/* Common target dependent code for GDB on ARM systems.
Copyright (C) 1988, 1989, 1991, 1992, 1993, 1995, 1996, 1998, 1999, 2000,
- 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
This file is part of GDB.
#include "gdb_assert.h"
#include "vec.h"
+#include "features/arm-with-m.c"
+
static int arm_debug;
/* Macros for setting and testing a bit in a minimal symbol that marks
{
"auto",
"arm",
- "thumb"
+ "thumb",
+ NULL
};
static const char *arm_fallback_mode_string = "auto";
struct trad_frame_saved_reg *saved_regs;
};
+static CORE_ADDR arm_analyze_prologue (struct gdbarch *gdbarch,
+ CORE_ADDR prologue_start,
+ CORE_ADDR prologue_end,
+ struct arm_prologue_cache *cache);
+
+/* Architecture version for displaced stepping. This effects the behaviour of
+ certain instructions, and really should not be hard-wired. */
+
+#define DISPLACED_STEPPING_ARCH_VERSION 5
+
/* Addresses for calling Thumb functions have the bit 0 set.
Here are some macros to test, set, or clear bit 0 of addresses. */
#define IS_THUMB_ADDR(addr) ((addr) & 1)
int arm_apcs_32 = 1;
-/* Determine if FRAME is executing in Thumb mode. */
+/* Return the bit mask in ARM_PS_REGNUM that indicates Thumb mode. */
static int
+arm_psr_thumb_bit (struct gdbarch *gdbarch)
+{
+ if (gdbarch_tdep (gdbarch)->is_m)
+ return XPSR_T;
+ else
+ return CPSR_T;
+}
+
+/* Determine if FRAME is executing in Thumb mode. */
+
+int
arm_frame_is_thumb (struct frame_info *frame)
{
CORE_ADDR cpsr;
+ ULONGEST t_bit = arm_psr_thumb_bit (get_frame_arch (frame));
/* Every ARM frame unwinder can unwind the T bit of the CPSR, either
directly (from a signal frame or dummy frame) or by interpreting
trust the unwinders. */
cpsr = get_frame_register_unsigned (frame, ARM_PS_REGNUM);
- return (cpsr & CPSR_T) != 0;
+ return (cpsr & t_bit) != 0;
}
/* Callback for VEC_lower_bound. */
return lhs->value < rhs->value;
}
-/* Determine if the program counter specified in MEMADDR is in a Thumb
- function. This function should be called for addresses unrelated to
- any executing frame; otherwise, prefer arm_frame_is_thumb. */
+/* Search for the mapping symbol covering MEMADDR. If one is found,
+ return its type. Otherwise, return 0. If START is non-NULL,
+ set *START to the location of the mapping symbol. */
-static int
-arm_pc_is_thumb (CORE_ADDR memaddr)
+static char
+arm_find_mapping_symbol (CORE_ADDR memaddr, CORE_ADDR *start)
{
struct obj_section *sec;
- struct minimal_symbol *sym;
-
- /* If bit 0 of the address is set, assume this is a Thumb address. */
- if (IS_THUMB_ADDR (memaddr))
- return 1;
-
- /* If the user wants to override the symbol table, let him. */
- if (strcmp (arm_force_mode_string, "arm") == 0)
- return 0;
- if (strcmp (arm_force_mode_string, "thumb") == 0)
- return 1;
/* If there are mapping symbols, consult them. */
sec = find_pc_section (memaddr);
{
map_sym = VEC_index (arm_mapping_symbol_s, map, idx);
if (map_sym->value == map_key.value)
- return map_sym->type == 't';
+ {
+ if (start)
+ *start = map_sym->value + obj_section_addr (sec);
+ return map_sym->type;
+ }
}
if (idx > 0)
{
map_sym = VEC_index (arm_mapping_symbol_s, map, idx - 1);
- return map_sym->type == 't';
+ if (start)
+ *start = map_sym->value + obj_section_addr (sec);
+ return map_sym->type;
}
}
}
}
+ return 0;
+}
+
+static CORE_ADDR arm_get_next_pc_raw (struct frame_info *frame,
+ CORE_ADDR pc, int insert_bkpt);
+
+/* Determine if the program counter specified in MEMADDR is in a Thumb
+ function. This function should be called for addresses unrelated to
+ any executing frame; otherwise, prefer arm_frame_is_thumb. */
+
+static int
+arm_pc_is_thumb (struct gdbarch *gdbarch, CORE_ADDR memaddr)
+{
+ struct obj_section *sec;
+ struct minimal_symbol *sym;
+ char type;
+
+ /* If bit 0 of the address is set, assume this is a Thumb address. */
+ if (IS_THUMB_ADDR (memaddr))
+ return 1;
+
+ /* If the user wants to override the symbol table, let him. */
+ if (strcmp (arm_force_mode_string, "arm") == 0)
+ return 0;
+ if (strcmp (arm_force_mode_string, "thumb") == 0)
+ return 1;
+
+ /* ARM v6-M and v7-M are always in Thumb mode. */
+ if (gdbarch_tdep (gdbarch)->is_m)
+ return 1;
+
+ /* If there are mapping symbols, consult them. */
+ type = arm_find_mapping_symbol (memaddr, NULL);
+ if (type)
+ return type == 't';
+
/* Thumb functions have a "special" bit set in minimal symbols. */
sym = lookup_minimal_symbol_by_pc (memaddr);
if (sym)
target, then trust the current value of $cpsr. This lets
"display/i $pc" always show the correct mode (though if there is
a symbol table we will not reach here, so it still may not be
- displayed in the mode it will be executed). */
+ displayed in the mode it will be executed).
+
+ As a further heuristic if we detect that we are doing a single-step we
+ see what state executing the current instruction ends up with us being
+ in. */
if (target_has_registers)
- return arm_frame_is_thumb (get_current_frame ());
+ {
+ struct frame_info *current_frame = get_current_frame ();
+ CORE_ADDR current_pc = get_frame_pc (current_frame);
+ int is_thumb = arm_frame_is_thumb (current_frame);
+ CORE_ADDR next_pc;
+ if (memaddr == current_pc)
+ return is_thumb;
+ else
+ {
+ struct gdbarch *gdbarch = get_frame_arch (current_frame);
+ next_pc = arm_get_next_pc_raw (current_frame, current_pc, FALSE);
+ if (memaddr == gdbarch_addr_bits_remove (gdbarch, next_pc))
+ return IS_THUMB_ADDR (next_pc);
+ else
+ return is_thumb;
+ }
+ }
/* Otherwise we're out of luck; we assume ARM. */
return 0;
return val & ~1;
}
+/* Return 1 if PC is the start of a compiler helper function which
+ can be safely ignored during prologue skipping. */
+static int
+skip_prologue_function (CORE_ADDR pc)
+{
+ struct minimal_symbol *msym;
+ const char *name;
+
+ msym = lookup_minimal_symbol_by_pc (pc);
+ if (msym == NULL || SYMBOL_VALUE_ADDRESS (msym) != pc)
+ return 0;
+
+ name = SYMBOL_LINKAGE_NAME (msym);
+ if (name == NULL)
+ return 0;
+
+ /* The GNU linker's Thumb call stub to foo is named
+ __foo_from_thumb. */
+ if (strstr (name, "_from_thumb") != NULL)
+ name += 2;
+
+ /* On soft-float targets, __truncdfsf2 is called to convert promoted
+ arguments to their argument types in non-prototyped
+ functions. */
+ if (strncmp (name, "__truncdfsf2", strlen ("__truncdfsf2")) == 0)
+ return 1;
+ if (strncmp (name, "__aeabi_d2f", strlen ("__aeabi_d2f")) == 0)
+ return 1;
+
+ /* Internal functions related to thread-local storage. */
+ if (strncmp (name, "__tls_get_addr", strlen ("__tls_get_addr")) == 0)
+ return 1;
+ if (strncmp (name, "__aeabi_read_tp", strlen ("__aeabi_read_tp")) == 0)
+ return 1;
+
+ return 0;
+}
+
+/* Support routines for instruction parsing. */
+#define submask(x) ((1L << ((x) + 1)) - 1)
+#define bit(obj,st) (((obj) >> (st)) & 1)
+#define bits(obj,st,fn) (((obj) >> (st)) & submask ((fn) - (st)))
+#define sbits(obj,st,fn) \
+ ((long) (bits(obj,st,fn) | ((long) bit(obj,fn) * ~ submask (fn - st))))
+#define BranchDest(addr,instr) \
+ ((CORE_ADDR) (((long) (addr)) + 8 + (sbits (instr, 0, 23) << 2)))
+
+/* Decode immediate value; implements ThumbExpandImmediate pseudo-op. */
+
+static unsigned int
+thumb_expand_immediate (unsigned int imm)
+{
+ unsigned int count = imm >> 7;
+
+ if (count < 8)
+ switch (count / 2)
+ {
+ case 0:
+ return imm & 0xff;
+ case 1:
+ return (imm & 0xff) | ((imm & 0xff) << 16);
+ case 2:
+ return ((imm & 0xff) << 8) | ((imm & 0xff) << 24);
+ case 3:
+ return (imm & 0xff) | ((imm & 0xff) << 8)
+ | ((imm & 0xff) << 16) | ((imm & 0xff) << 24);
+ }
+
+ return (0x80 | (imm & 0x7f)) << (32 - count);
+}
+
+/* Return 1 if the 16-bit Thumb instruction INST might change
+ control flow, 0 otherwise. */
+
+static int
+thumb_instruction_changes_pc (unsigned short inst)
+{
+ if ((inst & 0xff00) == 0xbd00) /* pop {rlist, pc} */
+ return 1;
+
+ if ((inst & 0xf000) == 0xd000) /* conditional branch */
+ return 1;
+
+ if ((inst & 0xf800) == 0xe000) /* unconditional branch */
+ return 1;
+
+ if ((inst & 0xff00) == 0x4700) /* bx REG, blx REG */
+ return 1;
+
+ if ((inst & 0xff87) == 0x4687) /* mov pc, REG */
+ return 1;
+
+ if ((inst & 0xf500) == 0xb100) /* CBNZ or CBZ. */
+ return 1;
+
+ return 0;
+}
+
+/* Return 1 if the 32-bit Thumb instruction in INST1 and INST2
+ might change control flow, 0 otherwise. */
+
+static int
+thumb2_instruction_changes_pc (unsigned short inst1, unsigned short inst2)
+{
+ if ((inst1 & 0xf800) == 0xf000 && (inst2 & 0x8000) == 0x8000)
+ {
+ /* Branches and miscellaneous control instructions. */
+
+ if ((inst2 & 0x1000) != 0 || (inst2 & 0xd001) == 0xc000)
+ {
+ /* B, BL, BLX. */
+ return 1;
+ }
+ else if (inst1 == 0xf3de && (inst2 & 0xff00) == 0x3f00)
+ {
+ /* SUBS PC, LR, #imm8. */
+ return 1;
+ }
+ else if ((inst2 & 0xd000) == 0x8000 && (inst1 & 0x0380) != 0x0380)
+ {
+ /* Conditional branch. */
+ return 1;
+ }
+
+ return 0;
+ }
+
+ if ((inst1 & 0xfe50) == 0xe810)
+ {
+ /* Load multiple or RFE. */
+
+ if (bit (inst1, 7) && !bit (inst1, 8))
+ {
+ /* LDMIA or POP */
+ if (bit (inst2, 15))
+ return 1;
+ }
+ else if (!bit (inst1, 7) && bit (inst1, 8))
+ {
+ /* LDMDB */
+ if (bit (inst2, 15))
+ return 1;
+ }
+ else if (bit (inst1, 7) && bit (inst1, 8))
+ {
+ /* RFEIA */
+ return 1;
+ }
+ else if (!bit (inst1, 7) && !bit (inst1, 8))
+ {
+ /* RFEDB */
+ return 1;
+ }
+
+ return 0;
+ }
+
+ if ((inst1 & 0xffef) == 0xea4f && (inst2 & 0xfff0) == 0x0f00)
+ {
+ /* MOV PC or MOVS PC. */
+ return 1;
+ }
+
+ if ((inst1 & 0xff70) == 0xf850 && (inst2 & 0xf000) == 0xf000)
+ {
+ /* LDR PC. */
+ if (bits (inst1, 0, 3) == 15)
+ return 1;
+ if (bit (inst1, 7))
+ return 1;
+ if (bit (inst2, 11))
+ return 1;
+ if ((inst2 & 0x0fc0) == 0x0000)
+ return 1;
+
+ return 0;
+ }
+
+ if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf000)
+ {
+ /* TBB. */
+ return 1;
+ }
+
+ if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf010)
+ {
+ /* TBH. */
+ return 1;
+ }
+
+ return 0;
+}
+
/* Analyze a Thumb prologue, looking for a recognizable stack frame
and frame pointer. Scan until we encounter a store that could
- clobber the stack frame unexpectedly, or an unknown instruction. */
+ clobber the stack frame unexpectedly, or an unknown instruction.
+ Return the last address which is definitely safe to skip for an
+ initial breakpoint. */
static CORE_ADDR
thumb_analyze_prologue (struct gdbarch *gdbarch,
CORE_ADDR start, CORE_ADDR limit,
struct arm_prologue_cache *cache)
{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
int i;
pv_t regs[16];
struct pv_area *stack;
struct cleanup *back_to;
CORE_ADDR offset;
+ CORE_ADDR unrecognized_pc = 0;
for (i = 0; i < 16; i++)
regs[i] = pv_register (i, 0);
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM],
offset);
}
- else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */
- regs[THUMB_FP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM],
- (insn & 0xff) << 2);
+ else if ((insn & 0xf800) == 0xa800) /* add Rd, sp, #imm */
+ regs[bits (insn, 8, 10)] = pv_add_constant (regs[ARM_SP_REGNUM],
+ (insn & 0xff) << 2);
+ else if ((insn & 0xfe00) == 0x1c00 /* add Rd, Rn, #imm */
+ && pv_is_register (regs[bits (insn, 3, 5)], ARM_SP_REGNUM))
+ regs[bits (insn, 0, 2)] = pv_add_constant (regs[bits (insn, 3, 5)],
+ bits (insn, 6, 8));
+ else if ((insn & 0xf800) == 0x3000 /* add Rd, #imm */
+ && pv_is_register (regs[bits (insn, 8, 10)], ARM_SP_REGNUM))
+ regs[bits (insn, 8, 10)] = pv_add_constant (regs[bits (insn, 8, 10)],
+ bits (insn, 0, 7));
+ else if ((insn & 0xfe00) == 0x1800 /* add Rd, Rn, Rm */
+ && pv_is_register (regs[bits (insn, 6, 8)], ARM_SP_REGNUM)
+ && pv_is_constant (regs[bits (insn, 3, 5)]))
+ regs[bits (insn, 0, 2)] = pv_add (regs[bits (insn, 3, 5)],
+ regs[bits (insn, 6, 8)]);
+ else if ((insn & 0xff00) == 0x4400 /* add Rd, Rm */
+ && pv_is_constant (regs[bits (insn, 3, 6)]))
+ {
+ int rd = (bit (insn, 7) << 3) + bits (insn, 0, 2);
+ int rm = bits (insn, 3, 6);
+ regs[rd] = pv_add (regs[rd], regs[rm]);
+ }
else if ((insn & 0xff00) == 0x4600) /* mov hi, lo or mov lo, hi */
{
int dst_reg = (insn & 0x7) + ((insn & 0x80) >> 4);
pv_area_store (stack, addr, 4, regs[regno]);
}
- else
+ else if ((insn & 0xf800) == 0x6000) /* str rd, [rn, #off] */
{
- /* We don't know what this instruction is. We're finished
- scanning. NOTE: Recognizing more safe-to-ignore
- instructions here will improve support for optimized
- code. */
- break;
- }
+ int rd = bits (insn, 0, 2);
+ int rn = bits (insn, 3, 5);
+ pv_t addr;
- start += 2;
- }
+ offset = bits (insn, 6, 10) << 2;
+ addr = pv_add_constant (regs[rn], offset);
- if (cache == NULL)
- {
- do_cleanups (back_to);
- return start;
- }
+ if (pv_area_store_would_trash (stack, addr))
+ break;
- if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM))
- {
- /* Frame pointer is fp. Frame size is constant. */
- cache->framereg = ARM_FP_REGNUM;
- cache->framesize = -regs[ARM_FP_REGNUM].k;
- }
- else if (pv_is_register (regs[THUMB_FP_REGNUM], ARM_SP_REGNUM))
- {
- /* Frame pointer is r7. Frame size is constant. */
- cache->framereg = THUMB_FP_REGNUM;
- cache->framesize = -regs[THUMB_FP_REGNUM].k;
- }
- else if (pv_is_register (regs[ARM_SP_REGNUM], ARM_SP_REGNUM))
- {
- /* Try the stack pointer... this is a bit desperate. */
- cache->framereg = ARM_SP_REGNUM;
- cache->framesize = -regs[ARM_SP_REGNUM].k;
- }
- else
- {
- /* We're just out of luck. We don't know where the frame is. */
- cache->framereg = -1;
- cache->framesize = 0;
- }
+ pv_area_store (stack, addr, 4, regs[rd]);
+ }
+ else if (((insn & 0xf800) == 0x7000 /* strb Rd, [Rn, #off] */
+ || (insn & 0xf800) == 0x8000) /* strh Rd, [Rn, #off] */
+ && pv_is_register (regs[bits (insn, 3, 5)], ARM_SP_REGNUM))
+ /* Ignore stores of argument registers to the stack. */
+ ;
+ else if ((insn & 0xf800) == 0xc800 /* ldmia Rn!, { registers } */
+ && pv_is_register (regs[bits (insn, 8, 10)], ARM_SP_REGNUM))
+ /* Ignore block loads from the stack, potentially copying
+ parameters from memory. */
+ ;
+ else if ((insn & 0xf800) == 0x9800 /* ldr Rd, [Rn, #immed] */
+ || ((insn & 0xf800) == 0x6800 /* ldr Rd, [sp, #immed] */
+ && pv_is_register (regs[bits (insn, 3, 5)], ARM_SP_REGNUM)))
+ /* Similarly ignore single loads from the stack. */
+ ;
+ else if ((insn & 0xffc0) == 0x0000 /* lsls Rd, Rm, #0 */
+ || (insn & 0xffc0) == 0x1c00) /* add Rd, Rn, #0 */
+ /* Skip register copies, i.e. saves to another register
+ instead of the stack. */
+ ;
+ else if ((insn & 0xf800) == 0x2000) /* movs Rd, #imm */
+ /* Recognize constant loads; even with small stacks these are necessary
+ on Thumb. */
+ regs[bits (insn, 8, 10)] = pv_constant (bits (insn, 0, 7));
+ else if ((insn & 0xf800) == 0x4800) /* ldr Rd, [pc, #imm] */
+ {
+ /* Constant pool loads, for the same reason. */
+ unsigned int constant;
+ CORE_ADDR loc;
- for (i = 0; i < 16; i++)
- if (pv_area_find_reg (stack, gdbarch, i, &offset))
- cache->saved_regs[i].addr = offset;
+ loc = start + 4 + bits (insn, 0, 7) * 4;
+ constant = read_memory_unsigned_integer (loc, 4, byte_order);
+ regs[bits (insn, 8, 10)] = pv_constant (constant);
+ }
+ else if ((insn & 0xe000) == 0xe000)
+ {
+ unsigned short inst2;
- do_cleanups (back_to);
- return start;
-}
+ inst2 = read_memory_unsigned_integer (start + 2, 2,
+ byte_order_for_code);
-/* Advance the PC across any function entry prologue instructions to
- reach some "real" code.
+ if ((insn & 0xf800) == 0xf000 && (inst2 & 0xe800) == 0xe800)
+ {
+ /* BL, BLX. Allow some special function calls when
+ skipping the prologue; GCC generates these before
+ storing arguments to the stack. */
+ CORE_ADDR nextpc;
+ int j1, j2, imm1, imm2;
+
+ imm1 = sbits (insn, 0, 10);
+ imm2 = bits (inst2, 0, 10);
+ j1 = bit (inst2, 13);
+ j2 = bit (inst2, 11);
+
+ offset = ((imm1 << 12) + (imm2 << 1));
+ offset ^= ((!j2) << 22) | ((!j1) << 23);
+
+ nextpc = start + 4 + offset;
+ /* For BLX make sure to clear the low bits. */
+ if (bit (inst2, 12) == 0)
+ nextpc = nextpc & 0xfffffffc;
+
+ if (!skip_prologue_function (nextpc))
+ break;
+ }
- The APCS (ARM Procedure Call Standard) defines the following
- prologue:
+ else if ((insn & 0xffd0) == 0xe900 /* stmdb Rn{!}, { registers } */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ {
+ pv_t addr = regs[bits (insn, 0, 3)];
+ int regno;
- mov ip, sp
- [stmfd sp!, {a1,a2,a3,a4}]
- stmfd sp!, {...,fp,ip,lr,pc}
- [stfe f7, [sp, #-12]!]
- [stfe f6, [sp, #-12]!]
- [stfe f5, [sp, #-12]!]
- [stfe f4, [sp, #-12]!]
- sub fp, ip, #nn @@ nn == 20 or 4 depending on second insn */
+ if (pv_area_store_would_trash (stack, addr))
+ break;
-static CORE_ADDR
-arm_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
-{
- enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
- unsigned long inst;
- CORE_ADDR skip_pc;
- CORE_ADDR func_addr, limit_pc;
- struct symtab_and_line sal;
+ /* Calculate offsets of saved registers. */
+ for (regno = ARM_LR_REGNUM; regno >= 0; regno--)
+ if (inst2 & (1 << regno))
+ {
+ addr = pv_add_constant (addr, -4);
+ pv_area_store (stack, addr, 4, regs[regno]);
+ }
- /* If we're in a dummy frame, don't even try to skip the prologue. */
- if (deprecated_pc_in_call_dummy (gdbarch, pc))
- return pc;
+ if (insn & 0x0020)
+ regs[bits (insn, 0, 3)] = addr;
+ }
- /* See if we can determine the end of the prologue via the symbol table.
- If so, then return either PC, or the PC after the prologue, whichever
- is greater. */
- if (find_pc_partial_function (pc, NULL, &func_addr, NULL))
- {
- CORE_ADDR post_prologue_pc
- = skip_prologue_using_sal (gdbarch, func_addr);
- if (post_prologue_pc != 0)
- return max (pc, post_prologue_pc);
- }
+ else if ((insn & 0xff50) == 0xe940 /* strd Rt, Rt2, [Rn, #+/-imm]{!} */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ {
+ int regno1 = bits (inst2, 12, 15);
+ int regno2 = bits (inst2, 8, 11);
+ pv_t addr = regs[bits (insn, 0, 3)];
- /* Can't determine prologue from the symbol table, need to examine
- instructions. */
+ offset = inst2 & 0xff;
+ if (insn & 0x0080)
+ addr = pv_add_constant (addr, offset);
+ else
+ addr = pv_add_constant (addr, -offset);
- /* Find an upper limit on the function prologue using the debug
+ if (pv_area_store_would_trash (stack, addr))
+ break;
+
+ pv_area_store (stack, addr, 4, regs[regno1]);
+ pv_area_store (stack, pv_add_constant (addr, 4),
+ 4, regs[regno2]);
+
+ if (insn & 0x0020)
+ regs[bits (insn, 0, 3)] = addr;
+ }
+
+ else if ((insn & 0xfff0) == 0xf8c0 /* str Rt,[Rn,+/-#imm]{!} */
+ && (inst2 & 0x0c00) == 0x0c00
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ {
+ int regno = bits (inst2, 12, 15);
+ pv_t addr = regs[bits (insn, 0, 3)];
+
+ offset = inst2 & 0xff;
+ if (inst2 & 0x0200)
+ addr = pv_add_constant (addr, offset);
+ else
+ addr = pv_add_constant (addr, -offset);
+
+ if (pv_area_store_would_trash (stack, addr))
+ break;
+
+ pv_area_store (stack, addr, 4, regs[regno]);
+
+ if (inst2 & 0x0100)
+ regs[bits (insn, 0, 3)] = addr;
+ }
+
+ else if ((insn & 0xfff0) == 0xf8c0 /* str.w Rt,[Rn,#imm] */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ {
+ int regno = bits (inst2, 12, 15);
+ pv_t addr;
+
+ offset = inst2 & 0xfff;
+ addr = pv_add_constant (regs[bits (insn, 0, 3)], offset);
+
+ if (pv_area_store_would_trash (stack, addr))
+ break;
+
+ pv_area_store (stack, addr, 4, regs[regno]);
+ }
+
+ else if ((insn & 0xffd0) == 0xf880 /* str{bh}.w Rt,[Rn,#imm] */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Ignore stores of argument registers to the stack. */
+ ;
+
+ else if ((insn & 0xffd0) == 0xf800 /* str{bh} Rt,[Rn,#+/-imm] */
+ && (inst2 & 0x0d00) == 0x0c00
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Ignore stores of argument registers to the stack. */
+ ;
+
+ else if ((insn & 0xffd0) == 0xe890 /* ldmia Rn[!], { registers } */
+ && (inst2 & 0x8000) == 0x0000
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Ignore block loads from the stack, potentially copying
+ parameters from memory. */
+ ;
+
+ else if ((insn & 0xffb0) == 0xe950 /* ldrd Rt, Rt2, [Rn, #+/-imm] */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Similarly ignore dual loads from the stack. */
+ ;
+
+ else if ((insn & 0xfff0) == 0xf850 /* ldr Rt,[Rn,#+/-imm] */
+ && (inst2 & 0x0d00) == 0x0c00
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Similarly ignore single loads from the stack. */
+ ;
+
+ else if ((insn & 0xfff0) == 0xf8d0 /* ldr.w Rt,[Rn,#imm] */
+ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM))
+ /* Similarly ignore single loads from the stack. */
+ ;
+
+ else if ((insn & 0xfbf0) == 0xf100 /* add.w Rd, Rn, #imm */
+ && (inst2 & 0x8000) == 0x0000)
+ {
+ unsigned int imm = ((bits (insn, 10, 10) << 11)
+ | (bits (inst2, 12, 14) << 8)
+ | bits (inst2, 0, 7));
+
+ regs[bits (inst2, 8, 11)]
+ = pv_add_constant (regs[bits (insn, 0, 3)],
+ thumb_expand_immediate (imm));
+ }
+
+ else if ((insn & 0xfbf0) == 0xf200 /* addw Rd, Rn, #imm */
+ && (inst2 & 0x8000) == 0x0000)
+ {
+ unsigned int imm = ((bits (insn, 10, 10) << 11)
+ | (bits (inst2, 12, 14) << 8)
+ | bits (inst2, 0, 7));
+
+ regs[bits (inst2, 8, 11)]
+ = pv_add_constant (regs[bits (insn, 0, 3)], imm);
+ }
+
+ else if ((insn & 0xfbf0) == 0xf1a0 /* sub.w Rd, Rn, #imm */
+ && (inst2 & 0x8000) == 0x0000)
+ {
+ unsigned int imm = ((bits (insn, 10, 10) << 11)
+ | (bits (inst2, 12, 14) << 8)
+ | bits (inst2, 0, 7));
+
+ regs[bits (inst2, 8, 11)]
+ = pv_add_constant (regs[bits (insn, 0, 3)],
+ - (CORE_ADDR) thumb_expand_immediate (imm));
+ }
+
+ else if ((insn & 0xfbf0) == 0xf2a0 /* subw Rd, Rn, #imm */
+ && (inst2 & 0x8000) == 0x0000)
+ {
+ unsigned int imm = ((bits (insn, 10, 10) << 11)
+ | (bits (inst2, 12, 14) << 8)
+ | bits (inst2, 0, 7));
+
+ regs[bits (inst2, 8, 11)]
+ = pv_add_constant (regs[bits (insn, 0, 3)], - (CORE_ADDR) imm);
+ }
+
+ else if ((insn & 0xfbff) == 0xf04f) /* mov.w Rd, #const */
+ {
+ unsigned int imm = ((bits (insn, 10, 10) << 11)
+ | (bits (inst2, 12, 14) << 8)
+ | bits (inst2, 0, 7));
+
+ regs[bits (inst2, 8, 11)]
+ = pv_constant (thumb_expand_immediate (imm));
+ }
+
+ else if ((insn & 0xfbf0) == 0xf240) /* movw Rd, #const */
+ {
+ unsigned int imm = ((bits (insn, 0, 3) << 12)
+ | (bits (insn, 10, 10) << 11)
+ | (bits (inst2, 12, 14) << 8)
+ | bits (inst2, 0, 7));
+
+ regs[bits (inst2, 8, 11)] = pv_constant (imm);
+ }
+
+ else if (insn == 0xea5f /* mov.w Rd,Rm */
+ && (inst2 & 0xf0f0) == 0)
+ {
+ int dst_reg = (inst2 & 0x0f00) >> 8;
+ int src_reg = inst2 & 0xf;
+ regs[dst_reg] = regs[src_reg];
+ }
+
+ else if ((insn & 0xff7f) == 0xf85f) /* ldr.w Rt,<label> */
+ {
+ /* Constant pool loads. */
+ unsigned int constant;
+ CORE_ADDR loc;
+
+ offset = bits (insn, 0, 11);
+ if (insn & 0x0080)
+ loc = start + 4 + offset;
+ else
+ loc = start + 4 - offset;
+
+ constant = read_memory_unsigned_integer (loc, 4, byte_order);
+ regs[bits (inst2, 12, 15)] = pv_constant (constant);
+ }
+
+ else if ((insn & 0xff7f) == 0xe95f) /* ldrd Rt,Rt2,<label> */
+ {
+ /* Constant pool loads. */
+ unsigned int constant;
+ CORE_ADDR loc;
+
+ offset = bits (insn, 0, 7) << 2;
+ if (insn & 0x0080)
+ loc = start + 4 + offset;
+ else
+ loc = start + 4 - offset;
+
+ constant = read_memory_unsigned_integer (loc, 4, byte_order);
+ regs[bits (inst2, 12, 15)] = pv_constant (constant);
+
+ constant = read_memory_unsigned_integer (loc + 4, 4, byte_order);
+ regs[bits (inst2, 8, 11)] = pv_constant (constant);
+ }
+
+ else if (thumb2_instruction_changes_pc (insn, inst2))
+ {
+ /* Don't scan past anything that might change control flow. */
+ break;
+ }
+ else
+ {
+ /* The optimizer might shove anything into the prologue,
+ so we just skip what we don't recognize. */
+ unrecognized_pc = start;
+ }
+
+ start += 2;
+ }
+ else if (thumb_instruction_changes_pc (insn))
+ {
+ /* Don't scan past anything that might change control flow. */
+ break;
+ }
+ else
+ {
+ /* The optimizer might shove anything into the prologue,
+ so we just skip what we don't recognize. */
+ unrecognized_pc = start;
+ }
+
+ start += 2;
+ }
+
+ if (arm_debug)
+ fprintf_unfiltered (gdb_stdlog, "Prologue scan stopped at %s\n",
+ paddress (gdbarch, start));
+
+ if (unrecognized_pc == 0)
+ unrecognized_pc = start;
+
+ if (cache == NULL)
+ {
+ do_cleanups (back_to);
+ return unrecognized_pc;
+ }
+
+ if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM))
+ {
+ /* Frame pointer is fp. Frame size is constant. */
+ cache->framereg = ARM_FP_REGNUM;
+ cache->framesize = -regs[ARM_FP_REGNUM].k;
+ }
+ else if (pv_is_register (regs[THUMB_FP_REGNUM], ARM_SP_REGNUM))
+ {
+ /* Frame pointer is r7. Frame size is constant. */
+ cache->framereg = THUMB_FP_REGNUM;
+ cache->framesize = -regs[THUMB_FP_REGNUM].k;
+ }
+ else if (pv_is_register (regs[ARM_SP_REGNUM], ARM_SP_REGNUM))
+ {
+ /* Try the stack pointer... this is a bit desperate. */
+ cache->framereg = ARM_SP_REGNUM;
+ cache->framesize = -regs[ARM_SP_REGNUM].k;
+ }
+ else
+ {
+ /* We're just out of luck. We don't know where the frame is. */
+ cache->framereg = -1;
+ cache->framesize = 0;
+ }
+
+ for (i = 0; i < 16; i++)
+ if (pv_area_find_reg (stack, gdbarch, i, &offset))
+ cache->saved_regs[i].addr = offset;
+
+ do_cleanups (back_to);
+ return unrecognized_pc;
+}
+
+/* Advance the PC across any function entry prologue instructions to
+ reach some "real" code.
+
+ The APCS (ARM Procedure Call Standard) defines the following
+ prologue:
+
+ mov ip, sp
+ [stmfd sp!, {a1,a2,a3,a4}]
+ stmfd sp!, {...,fp,ip,lr,pc}
+ [stfe f7, [sp, #-12]!]
+ [stfe f6, [sp, #-12]!]
+ [stfe f5, [sp, #-12]!]
+ [stfe f4, [sp, #-12]!]
+ sub fp, ip, #nn @@ nn == 20 or 4 depending on second insn */
+
+static CORE_ADDR
+arm_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ unsigned long inst;
+ CORE_ADDR skip_pc;
+ CORE_ADDR func_addr, limit_pc;
+ struct symtab_and_line sal;
+
+ /* See if we can determine the end of the prologue via the symbol table.
+ If so, then return either PC, or the PC after the prologue, whichever
+ is greater. */
+ if (find_pc_partial_function (pc, NULL, &func_addr, NULL))
+ {
+ CORE_ADDR post_prologue_pc
+ = skip_prologue_using_sal (gdbarch, func_addr);
+ struct symtab *s = find_pc_symtab (func_addr);
+
+ /* GCC always emits a line note before the prologue and another
+ one after, even if the two are at the same address or on the
+ same line. Take advantage of this so that we do not need to
+ know every instruction that might appear in the prologue. We
+ will have producer information for most binaries; if it is
+ missing (e.g. for -gstabs), assuming the GNU tools. */
+ if (post_prologue_pc
+ && (s == NULL
+ || s->producer == NULL
+ || strncmp (s->producer, "GNU ", sizeof ("GNU ") - 1) == 0))
+ return post_prologue_pc;
+
+ if (post_prologue_pc != 0)
+ {
+ CORE_ADDR analyzed_limit;
+
+ /* For non-GCC compilers, make sure the entire line is an
+ acceptable prologue; GDB will round this function's
+ return value up to the end of the following line so we
+ can not skip just part of a line (and we do not want to).
+
+ RealView does not treat the prologue specially, but does
+ associate prologue code with the opening brace; so this
+ lets us skip the first line if we think it is the opening
+ brace. */
+ if (arm_pc_is_thumb (gdbarch, func_addr))
+ analyzed_limit = thumb_analyze_prologue (gdbarch, func_addr,
+ post_prologue_pc, NULL);
+ else
+ analyzed_limit = arm_analyze_prologue (gdbarch, func_addr,
+ post_prologue_pc, NULL);
+
+ if (analyzed_limit != post_prologue_pc)
+ return func_addr;
+
+ return post_prologue_pc;
+ }
+ }
+
+ /* Can't determine prologue from the symbol table, need to examine
+ instructions. */
+
+ /* Find an upper limit on the function prologue using the debug
information. If the debug information could not be used to provide
that bound, then use an arbitrary large number as the upper bound. */
/* Like arm_scan_prologue, stop no later than pc + 64. */
/* Check if this is Thumb code. */
- if (arm_pc_is_thumb (pc))
+ if (arm_pc_is_thumb (gdbarch, pc))
return thumb_analyze_prologue (gdbarch, pc, limit_pc, NULL);
for (skip_pc = pc; skip_pc < limit_pc; skip_pc += 4)
if ((inst & 0xfffff000) == 0xe24dd000) /* sub sp, sp, #nn */
continue;
- if ((inst & 0xffffc000) == 0xe54b0000 || /* strb r(0123),[r11,#-nn] */
- (inst & 0xffffc0f0) == 0xe14b00b0 || /* strh r(0123),[r11,#-nn] */
- (inst & 0xffffc000) == 0xe50b0000) /* str r(0123),[r11,#-nn] */
+ if ((inst & 0xffffc000) == 0xe54b0000 /* strb r(0123),[r11,#-nn] */
+ || (inst & 0xffffc0f0) == 0xe14b00b0 /* strh r(0123),[r11,#-nn] */
+ || (inst & 0xffffc000) == 0xe50b0000) /* str r(0123),[r11,#-nn] */
continue;
- if ((inst & 0xffffc000) == 0xe5cd0000 || /* strb r(0123),[sp,#nn] */
- (inst & 0xffffc0f0) == 0xe1cd00b0 || /* strh r(0123),[sp,#nn] */
- (inst & 0xffffc000) == 0xe58d0000) /* str r(0123),[sp,#nn] */
+ if ((inst & 0xffffc000) == 0xe5cd0000 /* strb r(0123),[sp,#nn] */
+ || (inst & 0xffffc0f0) == 0xe1cd00b0 /* strh r(0123),[sp,#nn] */
+ || (inst & 0xffffc000) == 0xe58d0000) /* str r(0123),[sp,#nn] */
continue;
/* Un-recognized instruction; stop scanning. */
if (find_pc_partial_function (block_addr, NULL, &prologue_start,
&prologue_end))
{
- struct symtab_and_line sal = find_pc_line (prologue_start, 0);
-
- if (sal.line == 0) /* no line info, use current PC */
- prologue_end = prev_pc;
- else if (sal.end < prologue_end) /* next line begins after fn end */
- prologue_end = sal.end; /* (probably means no prologue) */
+ /* See comment in arm_scan_prologue for an explanation of
+ this heuristics. */
+ if (prologue_end > prologue_start + 64)
+ {
+ prologue_end = prologue_start + 64;
+ }
}
else
/* We're in the boondocks: we have no idea where the start of the
thumb_analyze_prologue (gdbarch, prologue_start, prologue_end, cache);
}
-/* This function decodes an ARM function prologue to determine:
- 1) the size of the stack frame
- 2) which registers are saved on it
- 3) the offsets of saved regs
- 4) the offset from the stack pointer to the frame pointer
- This information is stored in the "extra" fields of the frame_info.
-
- There are two basic forms for the ARM prologue. The fixed argument
- function call will look like:
-
- mov ip, sp
- stmfd sp!, {fp, ip, lr, pc}
- sub fp, ip, #4
- [sub sp, sp, #4]
-
- Which would create this stack frame (offsets relative to FP):
- IP -> 4 (caller's stack)
- FP -> 0 PC (points to address of stmfd instruction + 8 in callee)
- -4 LR (return address in caller)
- -8 IP (copy of caller's SP)
- -12 FP (caller's FP)
- SP -> -28 Local variables
-
- The frame size would thus be 32 bytes, and the frame offset would be
- 28 bytes. The stmfd call can also save any of the vN registers it
- plans to use, which increases the frame size accordingly.
-
- Note: The stored PC is 8 off of the STMFD instruction that stored it
- because the ARM Store instructions always store PC + 8 when you read
- the PC register.
-
- A variable argument function call will look like:
-
- mov ip, sp
- stmfd sp!, {a1, a2, a3, a4}
- stmfd sp!, {fp, ip, lr, pc}
- sub fp, ip, #20
-
- Which would create this stack frame (offsets relative to FP):
- IP -> 20 (caller's stack)
- 16 A4
- 12 A3
- 8 A2
- 4 A1
- FP -> 0 PC (points to address of stmfd instruction + 8 in callee)
- -4 LR (return address in caller)
- -8 IP (copy of caller's SP)
- -12 FP (caller's FP)
- SP -> -28 Local variables
-
- The frame size would thus be 48 bytes, and the frame offset would be
- 28 bytes.
-
- There is another potential complication, which is that the optimizer
- will try to separate the store of fp in the "stmfd" instruction from
- the "sub fp, ip, #NN" instruction. Almost anything can be there, so
- we just key on the stmfd, and then scan for the "sub fp, ip, #NN"...
-
- Also, note, the original version of the ARM toolchain claimed that there
- should be an
-
- instruction at the end of the prologue. I have never seen GCC produce
- this, and the ARM docs don't mention it. We still test for it below in
- case it happens...
-
- */
+/* Return 1 if THIS_INSTR might change control flow, 0 otherwise. */
-static void
-arm_scan_prologue (struct frame_info *this_frame,
- struct arm_prologue_cache *cache)
+static int
+arm_instruction_changes_pc (uint32_t this_instr)
+{
+ if (bits (this_instr, 28, 31) == INST_NV)
+ /* Unconditional instructions. */
+ switch (bits (this_instr, 24, 27))
+ {
+ case 0xa:
+ case 0xb:
+ /* Branch with Link and change to Thumb. */
+ return 1;
+ case 0xc:
+ case 0xd:
+ case 0xe:
+ /* Coprocessor register transfer. */
+ if (bits (this_instr, 12, 15) == 15)
+ error (_("Invalid update to pc in instruction"));
+ return 0;
+ default:
+ return 0;
+ }
+ else
+ switch (bits (this_instr, 25, 27))
+ {
+ case 0x0:
+ if (bits (this_instr, 23, 24) == 2 && bit (this_instr, 20) == 0)
+ {
+ /* Multiplies and extra load/stores. */
+ if (bit (this_instr, 4) == 1 && bit (this_instr, 7) == 1)
+ /* Neither multiplies nor extension load/stores are allowed
+ to modify PC. */
+ return 0;
+
+ /* Otherwise, miscellaneous instructions. */
+
+ /* BX <reg>, BXJ <reg>, BLX <reg> */
+ if (bits (this_instr, 4, 27) == 0x12fff1
+ || bits (this_instr, 4, 27) == 0x12fff2
+ || bits (this_instr, 4, 27) == 0x12fff3)
+ return 1;
+
+ /* Other miscellaneous instructions are unpredictable if they
+ modify PC. */
+ return 0;
+ }
+ /* Data processing instruction. Fall through. */
+
+ case 0x1:
+ if (bits (this_instr, 12, 15) == 15)
+ return 1;
+ else
+ return 0;
+
+ case 0x2:
+ case 0x3:
+ /* Media instructions and architecturally undefined instructions. */
+ if (bits (this_instr, 25, 27) == 3 && bit (this_instr, 4) == 1)
+ return 0;
+
+ /* Stores. */
+ if (bit (this_instr, 20) == 0)
+ return 0;
+
+ /* Loads. */
+ if (bits (this_instr, 12, 15) == ARM_PC_REGNUM)
+ return 1;
+ else
+ return 0;
+
+ case 0x4:
+ /* Load/store multiple. */
+ if (bit (this_instr, 20) == 1 && bit (this_instr, 15) == 1)
+ return 1;
+ else
+ return 0;
+
+ case 0x5:
+ /* Branch and branch with link. */
+ return 1;
+
+ case 0x6:
+ case 0x7:
+ /* Coprocessor transfers or SWIs can not affect PC. */
+ return 0;
+
+ default:
+ internal_error (__FILE__, __LINE__, "bad value in switch");
+ }
+}
+
+/* Analyze an ARM mode prologue starting at PROLOGUE_START and
+ continuing no further than PROLOGUE_END. If CACHE is non-NULL,
+ fill it in. Return the first address not recognized as a prologue
+ instruction.
+
+ We recognize all the instructions typically found in ARM prologues,
+ plus harmless instructions which can be skipped (either for analysis
+ purposes, or a more restrictive set that can be skipped when finding
+ the end of the prologue). */
+
+static CORE_ADDR
+arm_analyze_prologue (struct gdbarch *gdbarch,
+ CORE_ADDR prologue_start, CORE_ADDR prologue_end,
+ struct arm_prologue_cache *cache)
{
- struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
int regno;
- CORE_ADDR prologue_start, prologue_end, current_pc;
- CORE_ADDR prev_pc = get_frame_pc (this_frame);
- CORE_ADDR block_addr = get_frame_address_in_block (this_frame);
+ CORE_ADDR offset, current_pc;
pv_t regs[ARM_FPS_REGNUM];
struct pv_area *stack;
struct cleanup *back_to;
- CORE_ADDR offset;
-
- /* Assume there is no frame until proven otherwise. */
- cache->framereg = ARM_SP_REGNUM;
- cache->framesize = 0;
+ int framereg, framesize;
+ CORE_ADDR unrecognized_pc = 0;
- /* Check for Thumb prologue. */
- if (arm_frame_is_thumb (this_frame))
- {
- thumb_scan_prologue (gdbarch, prev_pc, block_addr, cache);
- return;
- }
+ /* Search the prologue looking for instructions that set up the
+ frame pointer, adjust the stack pointer, and save registers.
- /* Find the function prologue. If we can't find the function in
- the symbol table, peek in the stack frame to find the PC. */
- if (find_pc_partial_function (block_addr, NULL, &prologue_start,
- &prologue_end))
- {
- /* One way to find the end of the prologue (which works well
- for unoptimized code) is to do the following:
+ Be careful, however, and if it doesn't look like a prologue,
+ don't try to scan it. If, for instance, a frameless function
+ begins with stmfd sp!, then we will tell ourselves there is
+ a frame, which will confuse stack traceback, as well as "finish"
+ and other operations that rely on a knowledge of the stack
+ traceback. */
- struct symtab_and_line sal = find_pc_line (prologue_start, 0);
+ for (regno = 0; regno < ARM_FPS_REGNUM; regno++)
+ regs[regno] = pv_register (regno, 0);
+ stack = make_pv_area (ARM_SP_REGNUM, gdbarch_addr_bit (gdbarch));
+ back_to = make_cleanup_free_pv_area (stack);
- if (sal.line == 0)
- prologue_end = prev_pc;
- else if (sal.end < prologue_end)
- prologue_end = sal.end;
-
- This mechanism is very accurate so long as the optimizer
- doesn't move any instructions from the function body into the
- prologue. If this happens, sal.end will be the last
- instruction in the first hunk of prologue code just before
- the first instruction that the scheduler has moved from
- the body to the prologue.
-
- In order to make sure that we scan all of the prologue
- instructions, we use a slightly less accurate mechanism which
- may scan more than necessary. To help compensate for this
- lack of accuracy, the prologue scanning loop below contains
- several clauses which'll cause the loop to terminate early if
- an implausible prologue instruction is encountered.
-
- The expression
-
- prologue_start + 64
-
- is a suitable endpoint since it accounts for the largest
- possible prologue plus up to five instructions inserted by
- the scheduler. */
-
- if (prologue_end > prologue_start + 64)
- {
- prologue_end = prologue_start + 64; /* See above. */
- }
- }
- else
- {
- /* We have no symbol information. Our only option is to assume this
- function has a standard stack frame and the normal frame register.
- Then, we can find the value of our frame pointer on entrance to
- the callee (or at the present moment if this is the innermost frame).
- The value stored there should be the address of the stmfd + 8. */
- CORE_ADDR frame_loc;
- LONGEST return_value;
-
- frame_loc = get_frame_register_unsigned (this_frame, ARM_FP_REGNUM);
- if (!safe_read_memory_integer (frame_loc, 4, byte_order, &return_value))
- return;
- else
- {
- prologue_start = gdbarch_addr_bits_remove
- (gdbarch, return_value) - 8;
- prologue_end = prologue_start + 64; /* See above. */
- }
- }
-
- if (prev_pc < prologue_end)
- prologue_end = prev_pc;
-
- /* Now search the prologue looking for instructions that set up the
- frame pointer, adjust the stack pointer, and save registers.
-
- Be careful, however, and if it doesn't look like a prologue,
- don't try to scan it. If, for instance, a frameless function
- begins with stmfd sp!, then we will tell ourselves there is
- a frame, which will confuse stack traceback, as well as "finish"
- and other operations that rely on a knowledge of the stack
- traceback.
-
- In the APCS, the prologue should start with "mov ip, sp" so
- if we don't see this as the first insn, we will stop.
-
- [Note: This doesn't seem to be true any longer, so it's now an
- optional part of the prologue. - Kevin Buettner, 2001-11-20]
-
- [Note further: The "mov ip,sp" only seems to be missing in
- frameless functions at optimization level "-O2" or above,
- in which case it is often (but not always) replaced by
- "str lr, [sp, #-4]!". - Michael Snyder, 2002-04-23] */
-
- for (regno = 0; regno < ARM_FPS_REGNUM; regno++)
- regs[regno] = pv_register (regno, 0);
- stack = make_pv_area (ARM_SP_REGNUM, gdbarch_addr_bit (gdbarch));
- back_to = make_cleanup_free_pv_area (stack);
-
- for (current_pc = prologue_start;
- current_pc < prologue_end;
- current_pc += 4)
- {
- unsigned int insn
- = read_memory_unsigned_integer (current_pc, 4, byte_order_for_code);
+ for (current_pc = prologue_start;
+ current_pc < prologue_end;
+ current_pc += 4)
+ {
+ unsigned int insn
+ = read_memory_unsigned_integer (current_pc, 4, byte_order_for_code);
if (insn == 0xe1a0c00d) /* mov ip, sp */
{
regs[ARM_IP_REGNUM] = regs[ARM_SP_REGNUM];
continue;
}
- else if ((insn & 0xfffff000) == 0xe28dc000) /* add ip, sp #n */
+ else if ((insn & 0xfff00000) == 0xe2800000 /* add Rd, Rn, #n */
+ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
{
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
+ int rd = bits (insn, 12, 15);
imm = (imm >> rot) | (imm << (32 - rot));
- regs[ARM_IP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], imm);
+ regs[rd] = pv_add_constant (regs[bits (insn, 16, 19)], imm);
continue;
}
- else if ((insn & 0xfffff000) == 0xe24dc000) /* sub ip, sp #n */
+ else if ((insn & 0xfff00000) == 0xe2400000 /* sub Rd, Rn, #n */
+ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
{
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
+ int rd = bits (insn, 12, 15);
imm = (imm >> rot) | (imm << (32 - rot));
- regs[ARM_IP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -imm);
+ regs[rd] = pv_add_constant (regs[bits (insn, 16, 19)], -imm);
continue;
}
- else if (insn == 0xe52de004) /* str lr, [sp, #-4]! */
+ else if ((insn & 0xffff0fff) == 0xe52d0004) /* str Rd, [sp, #-4]! */
{
if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
break;
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -4);
- pv_area_store (stack, regs[ARM_SP_REGNUM], 4, regs[ARM_LR_REGNUM]);
+ pv_area_store (stack, regs[ARM_SP_REGNUM], 4,
+ regs[bits (insn, 12, 15)]);
continue;
}
else if ((insn & 0xffff0000) == 0xe92d0000)
pv_area_store (stack, regs[ARM_SP_REGNUM], 4, regs[regno]);
}
}
- else if ((insn & 0xffffc000) == 0xe54b0000 || /* strb rx,[r11,#-n] */
- (insn & 0xffffc0f0) == 0xe14b00b0 || /* strh rx,[r11,#-n] */
- (insn & 0xffffc000) == 0xe50b0000) /* str rx,[r11,#-n] */
+ else if ((insn & 0xffff0000) == 0xe54b0000 /* strb rx,[r11,#-n] */
+ || (insn & 0xffff00f0) == 0xe14b00b0 /* strh rx,[r11,#-n] */
+ || (insn & 0xffffc000) == 0xe50b0000) /* str rx,[r11,#-n] */
{
/* No need to add this to saved_regs -- it's just an arg reg. */
continue;
}
- else if ((insn & 0xffffc000) == 0xe5cd0000 || /* strb rx,[sp,#n] */
- (insn & 0xffffc0f0) == 0xe1cd00b0 || /* strh rx,[sp,#n] */
- (insn & 0xffffc000) == 0xe58d0000) /* str rx,[sp,#n] */
+ else if ((insn & 0xffff0000) == 0xe5cd0000 /* strb rx,[sp,#n] */
+ || (insn & 0xffff00f0) == 0xe1cd00b0 /* strh rx,[sp,#n] */
+ || (insn & 0xffffc000) == 0xe58d0000) /* str rx,[sp,#n] */
{
/* No need to add this to saved_regs -- it's just an arg reg. */
continue;
}
+ else if ((insn & 0xfff00000) == 0xe8800000 /* stm Rn, { registers } */
+ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
+ {
+ /* No need to add this to saved_regs -- it's just arg regs. */
+ continue;
+ }
else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */
{
unsigned imm = insn & 0xff; /* immediate value */
regs[fp_start_reg++]);
}
}
+ else if ((insn & 0xff000000) == 0xeb000000 && cache == NULL) /* bl */
+ {
+ /* Allow some special function calls when skipping the
+ prologue; GCC generates these before storing arguments to
+ the stack. */
+ CORE_ADDR dest = BranchDest (current_pc, insn);
+
+ if (skip_prologue_function (dest))
+ continue;
+ else
+ break;
+ }
else if ((insn & 0xf0000000) != 0xe0000000)
break; /* Condition not true, exit early */
- else if ((insn & 0xfe200000) == 0xe8200000) /* ldm? */
- break; /* Don't scan past a block load */
- else
- /* The optimizer might shove anything into the prologue,
- so we just skip what we don't recognize. */
+ else if (arm_instruction_changes_pc (insn))
+ /* Don't scan past anything that might change control flow. */
+ break;
+ else if ((insn & 0xfe500000) == 0xe8100000) /* ldm */
+ {
+ /* Ignore block loads from the stack, potentially copying
+ parameters from memory. */
+ if (pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
+ continue;
+ else
+ break;
+ }
+ else if ((insn & 0xfc500000) == 0xe4100000)
+ {
+ /* Similarly ignore single loads from the stack. */
+ if (pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
+ continue;
+ else
+ break;
+ }
+ else if ((insn & 0xffff0ff0) == 0xe1a00000)
+ /* MOV Rd, Rm. Skip register copies, i.e. saves to another
+ register instead of the stack. */
continue;
+ else
+ {
+ /* The optimizer might shove anything into the prologue,
+ so we just skip what we don't recognize. */
+ unrecognized_pc = current_pc;
+ continue;
+ }
}
+ if (unrecognized_pc == 0)
+ unrecognized_pc = current_pc;
+
/* The frame size is just the distance from the frame register
to the original stack pointer. */
if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM))
{
/* Frame pointer is fp. */
- cache->framereg = ARM_FP_REGNUM;
- cache->framesize = -regs[ARM_FP_REGNUM].k;
+ framereg = ARM_FP_REGNUM;
+ framesize = -regs[ARM_FP_REGNUM].k;
}
else if (pv_is_register (regs[ARM_SP_REGNUM], ARM_SP_REGNUM))
{
/* Try the stack pointer... this is a bit desperate. */
- cache->framereg = ARM_SP_REGNUM;
- cache->framesize = -regs[ARM_SP_REGNUM].k;
+ framereg = ARM_SP_REGNUM;
+ framesize = -regs[ARM_SP_REGNUM].k;
}
else
{
/* We're just out of luck. We don't know where the frame is. */
- cache->framereg = -1;
- cache->framesize = 0;
+ framereg = -1;
+ framesize = 0;
}
- for (regno = 0; regno < ARM_FPS_REGNUM; regno++)
- if (pv_area_find_reg (stack, gdbarch, regno, &offset))
- cache->saved_regs[regno].addr = offset;
+ if (cache)
+ {
+ cache->framereg = framereg;
+ cache->framesize = framesize;
+
+ for (regno = 0; regno < ARM_FPS_REGNUM; regno++)
+ if (pv_area_find_reg (stack, gdbarch, regno, &offset))
+ cache->saved_regs[regno].addr = offset;
+ }
+
+ if (arm_debug)
+ fprintf_unfiltered (gdb_stdlog, "Prologue scan stopped at %s\n",
+ paddress (gdbarch, unrecognized_pc));
do_cleanups (back_to);
+ return unrecognized_pc;
+}
+
+static void
+arm_scan_prologue (struct frame_info *this_frame,
+ struct arm_prologue_cache *cache)
+{
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ int regno;
+ CORE_ADDR prologue_start, prologue_end, current_pc;
+ CORE_ADDR prev_pc = get_frame_pc (this_frame);
+ CORE_ADDR block_addr = get_frame_address_in_block (this_frame);
+ pv_t regs[ARM_FPS_REGNUM];
+ struct pv_area *stack;
+ struct cleanup *back_to;
+ CORE_ADDR offset;
+
+ /* Assume there is no frame until proven otherwise. */
+ cache->framereg = ARM_SP_REGNUM;
+ cache->framesize = 0;
+
+ /* Check for Thumb prologue. */
+ if (arm_frame_is_thumb (this_frame))
+ {
+ thumb_scan_prologue (gdbarch, prev_pc, block_addr, cache);
+ return;
+ }
+
+ /* Find the function prologue. If we can't find the function in
+ the symbol table, peek in the stack frame to find the PC. */
+ if (find_pc_partial_function (block_addr, NULL, &prologue_start,
+ &prologue_end))
+ {
+ /* One way to find the end of the prologue (which works well
+ for unoptimized code) is to do the following:
+
+ struct symtab_and_line sal = find_pc_line (prologue_start, 0);
+
+ if (sal.line == 0)
+ prologue_end = prev_pc;
+ else if (sal.end < prologue_end)
+ prologue_end = sal.end;
+
+ This mechanism is very accurate so long as the optimizer
+ doesn't move any instructions from the function body into the
+ prologue. If this happens, sal.end will be the last
+ instruction in the first hunk of prologue code just before
+ the first instruction that the scheduler has moved from
+ the body to the prologue.
+
+ In order to make sure that we scan all of the prologue
+ instructions, we use a slightly less accurate mechanism which
+ may scan more than necessary. To help compensate for this
+ lack of accuracy, the prologue scanning loop below contains
+ several clauses which'll cause the loop to terminate early if
+ an implausible prologue instruction is encountered.
+
+ The expression
+
+ prologue_start + 64
+
+ is a suitable endpoint since it accounts for the largest
+ possible prologue plus up to five instructions inserted by
+ the scheduler. */
+
+ if (prologue_end > prologue_start + 64)
+ {
+ prologue_end = prologue_start + 64; /* See above. */
+ }
+ }
+ else
+ {
+ /* We have no symbol information. Our only option is to assume this
+ function has a standard stack frame and the normal frame register.
+ Then, we can find the value of our frame pointer on entrance to
+ the callee (or at the present moment if this is the innermost frame).
+ The value stored there should be the address of the stmfd + 8. */
+ CORE_ADDR frame_loc;
+ LONGEST return_value;
+
+ frame_loc = get_frame_register_unsigned (this_frame, ARM_FP_REGNUM);
+ if (!safe_read_memory_integer (frame_loc, 4, byte_order, &return_value))
+ return;
+ else
+ {
+ prologue_start = gdbarch_addr_bits_remove
+ (gdbarch, return_value) - 8;
+ prologue_end = prologue_start + 64; /* See above. */
+ }
+ }
+
+ if (prev_pc < prologue_end)
+ prologue_end = prev_pc;
+
+ arm_analyze_prologue (gdbarch, prologue_start, prologue_end, cache);
}
static struct arm_prologue_cache *
if (prev_regnum == ARM_PS_REGNUM)
{
CORE_ADDR lr, cpsr;
+ ULONGEST t_bit = arm_psr_thumb_bit (gdbarch);
cpsr = get_frame_register_unsigned (this_frame, prev_regnum);
lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
if (IS_THUMB_ADDR (lr))
- cpsr |= CPSR_T;
+ cpsr |= t_bit;
else
- cpsr &= ~CPSR_T;
+ cpsr &= ~t_bit;
return frame_unwind_got_constant (this_frame, prev_regnum, cpsr);
}
static struct arm_prologue_cache *
arm_make_stub_cache (struct frame_info *this_frame)
{
- int reg;
struct arm_prologue_cache *cache;
- CORE_ADDR unwound_fp;
cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache);
cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
addr_in_block = get_frame_address_in_block (this_frame);
if (in_plt_section (addr_in_block, NULL)
+ /* We also use the stub winder if the target memory is unreadable
+ to avoid having the prologue unwinder trying to read it. */
|| target_read_memory (get_frame_pc (this_frame), dummy, 4) != 0)
return 1;
{
struct gdbarch * gdbarch = get_frame_arch (this_frame);
CORE_ADDR lr, cpsr;
+ ULONGEST t_bit = arm_psr_thumb_bit (gdbarch);
switch (regnum)
{
cpsr = get_frame_register_unsigned (this_frame, regnum);
lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
if (IS_THUMB_ADDR (lr))
- cpsr |= CPSR_T;
+ cpsr |= t_bit;
else
- cpsr &= ~CPSR_T;
+ cpsr &= ~t_bit;
return frame_unwind_got_constant (this_frame, regnum, cpsr);
default:
}
}
-/* When arguments must be pushed onto the stack, they go on in reverse
- order. The code below implements a FILO (stack) to do this. */
+/* Return true if we are in the function's epilogue, i.e. after the
+ instruction that destroyed the function's stack frame. */
-struct stack_item
+static int
+thumb_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
{
- int len;
- struct stack_item *prev;
- void *data;
-};
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ unsigned int insn, insn2;
+ int found_return = 0, found_stack_adjust = 0;
+ CORE_ADDR func_start, func_end;
+ CORE_ADDR scan_pc;
+ gdb_byte buf[4];
-static struct stack_item *
-push_stack_item (struct stack_item *prev, void *contents, int len)
-{
- struct stack_item *si;
- si = xmalloc (sizeof (struct stack_item));
- si->data = xmalloc (len);
- si->len = len;
- si->prev = prev;
- memcpy (si->data, contents, len);
- return si;
-}
+ if (!find_pc_partial_function (pc, NULL, &func_start, &func_end))
+ return 0;
-static struct stack_item *
-pop_stack_item (struct stack_item *si)
-{
- struct stack_item *dead = si;
- si = si->prev;
- xfree (dead->data);
- xfree (dead);
- return si;
-}
+ /* The epilogue is a sequence of instructions along the following lines:
+ - add stack frame size to SP or FP
+ - [if frame pointer used] restore SP from FP
+ - restore registers from SP [may include PC]
+ - a return-type instruction [if PC wasn't already restored]
-/* Return the alignment (in bytes) of the given type. */
+ In a first pass, we scan forward from the current PC and verify the
+ instructions we find as compatible with this sequence, ending in a
+ return instruction.
-static int
-arm_type_align (struct type *t)
-{
- int n;
- int align;
- int falign;
+ However, this is not sufficient to distinguish indirect function calls
+ within a function from indirect tail calls in the epilogue in some cases.
+ Therefore, if we didn't already find any SP-changing instruction during
+ forward scan, we add a backward scanning heuristic to ensure we actually
+ are in the epilogue. */
- t = check_typedef (t);
- switch (TYPE_CODE (t))
+ scan_pc = pc;
+ while (scan_pc < func_end && !found_return)
{
- default:
- /* Should never happen. */
- internal_error (__FILE__, __LINE__, _("unknown type alignment"));
- return 4;
+ if (target_read_memory (scan_pc, buf, 2))
+ break;
- case TYPE_CODE_PTR:
- case TYPE_CODE_ENUM:
- case TYPE_CODE_INT:
- case TYPE_CODE_FLT:
- case TYPE_CODE_SET:
- case TYPE_CODE_RANGE:
- case TYPE_CODE_BITSTRING:
- case TYPE_CODE_REF:
- case TYPE_CODE_CHAR:
- case TYPE_CODE_BOOL:
- return TYPE_LENGTH (t);
+ scan_pc += 2;
+ insn = extract_unsigned_integer (buf, 2, byte_order_for_code);
+
+ if ((insn & 0xff80) == 0x4700) /* bx <Rm> */
+ found_return = 1;
+ else if (insn == 0x46f7) /* mov pc, lr */
+ found_return = 1;
+ else if (insn == 0x46bd) /* mov sp, r7 */
+ found_stack_adjust = 1;
+ else if ((insn & 0xff00) == 0xb000) /* add sp, imm or sub sp, imm */
+ found_stack_adjust = 1;
+ else if ((insn & 0xfe00) == 0xbc00) /* pop <registers> */
+ {
+ found_stack_adjust = 1;
+ if (insn & 0x0100) /* <registers> include PC. */
+ found_return = 1;
+ }
+ else if ((insn & 0xe000) == 0xe000) /* 32-bit Thumb-2 instruction */
+ {
+ if (target_read_memory (scan_pc, buf, 2))
+ break;
- case TYPE_CODE_ARRAY:
- case TYPE_CODE_COMPLEX:
+ scan_pc += 2;
+ insn2 = extract_unsigned_integer (buf, 2, byte_order_for_code);
+
+ if (insn == 0xe8bd) /* ldm.w sp!, <registers> */
+ {
+ found_stack_adjust = 1;
+ if (insn2 & 0x8000) /* <registers> include PC. */
+ found_return = 1;
+ }
+ else if (insn == 0xf85d /* ldr.w <Rt>, [sp], #4 */
+ && (insn2 & 0x0fff) == 0x0b04)
+ {
+ found_stack_adjust = 1;
+ if ((insn2 & 0xf000) == 0xf000) /* <Rt> is PC. */
+ found_return = 1;
+ }
+ else if ((insn & 0xffbf) == 0xecbd /* vldm sp!, <list> */
+ && (insn2 & 0x0e00) == 0x0a00)
+ found_stack_adjust = 1;
+ else
+ break;
+ }
+ else
+ break;
+ }
+
+ if (!found_return)
+ return 0;
+
+ /* Since any instruction in the epilogue sequence, with the possible
+ exception of return itself, updates the stack pointer, we need to
+ scan backwards for at most one instruction. Try either a 16-bit or
+ a 32-bit instruction. This is just a heuristic, so we do not worry
+ too much about false positives.*/
+
+ if (!found_stack_adjust)
+ {
+ if (pc - 4 < func_start)
+ return 0;
+ if (target_read_memory (pc - 4, buf, 4))
+ return 0;
+
+ insn = extract_unsigned_integer (buf, 2, byte_order_for_code);
+ insn2 = extract_unsigned_integer (buf + 2, 2, byte_order_for_code);
+
+ if (insn2 == 0x46bd) /* mov sp, r7 */
+ found_stack_adjust = 1;
+ else if ((insn2 & 0xff00) == 0xb000) /* add sp, imm or sub sp, imm */
+ found_stack_adjust = 1;
+ else if ((insn2 & 0xff00) == 0xbc00) /* pop <registers> without PC */
+ found_stack_adjust = 1;
+ else if (insn == 0xe8bd) /* ldm.w sp!, <registers> */
+ found_stack_adjust = 1;
+ else if (insn == 0xf85d /* ldr.w <Rt>, [sp], #4 */
+ && (insn2 & 0x0fff) == 0x0b04)
+ found_stack_adjust = 1;
+ else if ((insn & 0xffbf) == 0xecbd /* vldm sp!, <list> */
+ && (insn2 & 0x0e00) == 0x0a00)
+ found_stack_adjust = 1;
+ }
+
+ return found_stack_adjust;
+}
+
+/* Return true if we are in the function's epilogue, i.e. after the
+ instruction that destroyed the function's stack frame. */
+
+static int
+arm_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ unsigned int insn;
+ int found_return, found_stack_adjust;
+ CORE_ADDR func_start, func_end;
+
+ if (arm_pc_is_thumb (gdbarch, pc))
+ return thumb_in_function_epilogue_p (gdbarch, pc);
+
+ if (!find_pc_partial_function (pc, NULL, &func_start, &func_end))
+ return 0;
+
+ /* We are in the epilogue if the previous instruction was a stack
+ adjustment and the next instruction is a possible return (bx, mov
+ pc, or pop). We could have to scan backwards to find the stack
+ adjustment, or forwards to find the return, but this is a decent
+ approximation. First scan forwards. */
+
+ found_return = 0;
+ insn = read_memory_unsigned_integer (pc, 4, byte_order_for_code);
+ if (bits (insn, 28, 31) != INST_NV)
+ {
+ if ((insn & 0x0ffffff0) == 0x012fff10)
+ /* BX. */
+ found_return = 1;
+ else if ((insn & 0x0ffffff0) == 0x01a0f000)
+ /* MOV PC. */
+ found_return = 1;
+ else if ((insn & 0x0fff0000) == 0x08bd0000
+ && (insn & 0x0000c000) != 0)
+ /* POP (LDMIA), including PC or LR. */
+ found_return = 1;
+ }
+
+ if (!found_return)
+ return 0;
+
+ /* Scan backwards. This is just a heuristic, so do not worry about
+ false positives from mode changes. */
+
+ if (pc < func_start + 4)
+ return 0;
+
+ insn = read_memory_unsigned_integer (pc - 4, 4, byte_order_for_code);
+ if (bits (insn, 28, 31) != INST_NV)
+ {
+ if ((insn & 0x0df0f000) == 0x0080d000)
+ /* ADD SP (register or immediate). */
+ found_stack_adjust = 1;
+ else if ((insn & 0x0df0f000) == 0x0040d000)
+ /* SUB SP (register or immediate). */
+ found_stack_adjust = 1;
+ else if ((insn & 0x0ffffff0) == 0x01a0d000)
+ /* MOV SP. */
+ found_return = 1;
+ else if ((insn & 0x0fff0000) == 0x08bd0000)
+ /* POP (LDMIA). */
+ found_stack_adjust = 1;
+ }
+
+ if (found_stack_adjust)
+ return 1;
+
+ return 0;
+}
+
+
+/* When arguments must be pushed onto the stack, they go on in reverse
+ order. The code below implements a FILO (stack) to do this. */
+
+struct stack_item
+{
+ int len;
+ struct stack_item *prev;
+ void *data;
+};
+
+static struct stack_item *
+push_stack_item (struct stack_item *prev, const void *contents, int len)
+{
+ struct stack_item *si;
+ si = xmalloc (sizeof (struct stack_item));
+ si->data = xmalloc (len);
+ si->len = len;
+ si->prev = prev;
+ memcpy (si->data, contents, len);
+ return si;
+}
+
+static struct stack_item *
+pop_stack_item (struct stack_item *si)
+{
+ struct stack_item *dead = si;
+ si = si->prev;
+ xfree (dead->data);
+ xfree (dead);
+ return si;
+}
+
+
+/* Return the alignment (in bytes) of the given type. */
+
+static int
+arm_type_align (struct type *t)
+{
+ int n;
+ int align;
+ int falign;
+
+ t = check_typedef (t);
+ switch (TYPE_CODE (t))
+ {
+ default:
+ /* Should never happen. */
+ internal_error (__FILE__, __LINE__, _("unknown type alignment"));
+ return 4;
+
+ case TYPE_CODE_PTR:
+ case TYPE_CODE_ENUM:
+ case TYPE_CODE_INT:
+ case TYPE_CODE_FLT:
+ case TYPE_CODE_SET:
+ case TYPE_CODE_RANGE:
+ case TYPE_CODE_BITSTRING:
+ case TYPE_CODE_REF:
+ case TYPE_CODE_CHAR:
+ case TYPE_CODE_BOOL:
+ return TYPE_LENGTH (t);
+
+ case TYPE_CODE_ARRAY:
+ case TYPE_CODE_COMPLEX:
/* TODO: What about vector types? */
return arm_type_align (TYPE_TARGET_TYPE (t));
/* Set the return address. For the ARM, the return breakpoint is
always at BP_ADDR. */
- /* XXX Fix for Thumb. */
+ if (arm_pc_is_thumb (gdbarch, bp_addr))
+ bp_addr |= 1;
regcache_cooked_write_unsigned (regcache, ARM_LR_REGNUM, bp_addr);
/* Walk through the list of args and determine how large a temporary
struct type *arg_type;
struct type *target_type;
enum type_code typecode;
- bfd_byte *val;
+ const bfd_byte *val;
int align;
enum arm_vfp_cprc_base_type vfp_base_type;
int vfp_base_count;
len = TYPE_LENGTH (arg_type);
target_type = TYPE_TARGET_TYPE (arg_type);
typecode = TYPE_CODE (arg_type);
- val = value_contents_writeable (args[argnum]);
+ val = value_contents (args[argnum]);
align = arm_type_align (arg_type);
/* Round alignment up to a whole number of words. */
the THUMB bit in it. */
if (TYPE_CODE_PTR == typecode
&& target_type != NULL
- && TYPE_CODE_FUNC == TYPE_CODE (target_type))
+ && TYPE_CODE_FUNC == TYPE_CODE (check_typedef (target_type)))
{
CORE_ADDR regval = extract_unsigned_integer (val, len, byte_order);
- if (arm_pc_is_thumb (regval))
+ if (arm_pc_is_thumb (gdbarch, regval))
{
- val = alloca (len);
- store_unsigned_integer (val, len, byte_order,
+ bfd_byte *copy = alloca (len);
+ store_unsigned_integer (copy, len, byte_order,
MAKE_THUMB_ADDR (regval));
+ val = copy;
}
}
case INST_LT:
return (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0));
case INST_GT:
- return (((status_reg & FLAG_Z) == 0) &&
- (((status_reg & FLAG_N) == 0) == ((status_reg & FLAG_V) == 0)));
+ return (((status_reg & FLAG_Z) == 0)
+ && (((status_reg & FLAG_N) == 0)
+ == ((status_reg & FLAG_V) == 0)));
case INST_LE:
- return (((status_reg & FLAG_Z) != 0) ||
- (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0)));
+ return (((status_reg & FLAG_Z) != 0)
+ || (((status_reg & FLAG_N) == 0)
+ != ((status_reg & FLAG_V) == 0)));
}
return 1;
}
-/* Support routines for single stepping. Calculate the next PC value. */
-#define submask(x) ((1L << ((x) + 1)) - 1)
-#define bit(obj,st) (((obj) >> (st)) & 1)
-#define bits(obj,st,fn) (((obj) >> (st)) & submask ((fn) - (st)))
-#define sbits(obj,st,fn) \
- ((long) (bits(obj,st,fn) | ((long) bit(obj,fn) * ~ submask (fn - st))))
-#define BranchDest(addr,instr) \
- ((CORE_ADDR) (((long) (addr)) + 8 + (sbits (instr, 0, 23) << 2)))
-#define ARM_PC_32 1
-
static unsigned long
shifted_reg_val (struct frame_info *frame, unsigned long inst, int carry,
unsigned long pc_val, unsigned long status_reg)
shift = bits (inst, 7, 11);
res = (rm == 15
- ? ((pc_val | (ARM_PC_32 ? 0 : status_reg))
- + (bit (inst, 4) ? 12 : 8))
+ ? (pc_val + (bit (inst, 4) ? 12 : 8))
: get_frame_register_unsigned (frame, rm));
switch (shifttype)
return nbits;
}
+/* Return the size in bytes of the complete Thumb instruction whose
+ first halfword is INST1. */
+
+static int
+thumb_insn_size (unsigned short inst1)
+{
+ if ((inst1 & 0xe000) == 0xe000 && (inst1 & 0x1800) != 0)
+ return 4;
+ else
+ return 2;
+}
+
+static int
+thumb_advance_itstate (unsigned int itstate)
+{
+ /* Preserve IT[7:5], the first three bits of the condition. Shift
+ the upcoming condition flags left by one bit. */
+ itstate = (itstate & 0xe0) | ((itstate << 1) & 0x1f);
+
+ /* If we have finished the IT block, clear the state. */
+ if ((itstate & 0x0f) == 0)
+ itstate = 0;
+
+ return itstate;
+}
+
+/* Find the next PC after the current instruction executes. In some
+ cases we can not statically determine the answer (see the IT state
+ handling in this function); in that case, a breakpoint may be
+ inserted in addition to the returned PC, which will be used to set
+ another breakpoint by our caller. */
+
static CORE_ADDR
-thumb_get_next_pc (struct frame_info *frame, CORE_ADDR pc)
+thumb_get_next_pc_raw (struct frame_info *frame, CORE_ADDR pc, int insert_bkpt)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct address_space *aspace = get_frame_address_space (frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
unsigned long pc_val = ((unsigned long) pc) + 4; /* PC after prefetch */
unsigned short inst1;
CORE_ADDR nextpc = pc + 2; /* default is next instruction */
unsigned long offset;
+ ULONGEST status, itstate;
+
+ nextpc = MAKE_THUMB_ADDR (nextpc);
+ pc_val = MAKE_THUMB_ADDR (pc_val);
inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
+ /* Thumb-2 conditional execution support. There are eight bits in
+ the CPSR which describe conditional execution state. Once
+ reconstructed (they're in a funny order), the low five bits
+ describe the low bit of the condition for each instruction and
+ how many instructions remain. The high three bits describe the
+ base condition. One of the low four bits will be set if an IT
+ block is active. These bits read as zero on earlier
+ processors. */
+ status = get_frame_register_unsigned (frame, ARM_PS_REGNUM);
+ itstate = ((status >> 8) & 0xfc) | ((status >> 25) & 0x3);
+
+ /* If-Then handling. On GNU/Linux, where this routine is used, we
+ use an undefined instruction as a breakpoint. Unlike BKPT, IT
+ can disable execution of the undefined instruction. So we might
+ miss the breakpoint if we set it on a skipped conditional
+ instruction. Because conditional instructions can change the
+ flags, affecting the execution of further instructions, we may
+ need to set two breakpoints. */
+
+ if (gdbarch_tdep (gdbarch)->thumb2_breakpoint != NULL)
+ {
+ if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
+ {
+ /* An IT instruction. Because this instruction does not
+ modify the flags, we can accurately predict the next
+ executed instruction. */
+ itstate = inst1 & 0x00ff;
+ pc += thumb_insn_size (inst1);
+
+ while (itstate != 0 && ! condition_true (itstate >> 4, status))
+ {
+ inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
+ pc += thumb_insn_size (inst1);
+ itstate = thumb_advance_itstate (itstate);
+ }
+
+ return MAKE_THUMB_ADDR (pc);
+ }
+ else if (itstate != 0)
+ {
+ /* We are in a conditional block. Check the condition. */
+ if (! condition_true (itstate >> 4, status))
+ {
+ /* Advance to the next executed instruction. */
+ pc += thumb_insn_size (inst1);
+ itstate = thumb_advance_itstate (itstate);
+
+ while (itstate != 0 && ! condition_true (itstate >> 4, status))
+ {
+ inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
+ pc += thumb_insn_size (inst1);
+ itstate = thumb_advance_itstate (itstate);
+ }
+
+ return MAKE_THUMB_ADDR (pc);
+ }
+ else if ((itstate & 0x0f) == 0x08)
+ {
+ /* This is the last instruction of the conditional
+ block, and it is executed. We can handle it normally
+ because the following instruction is not conditional,
+ and we must handle it normally because it is
+ permitted to branch. Fall through. */
+ }
+ else
+ {
+ int cond_negated;
+
+ /* There are conditional instructions after this one.
+ If this instruction modifies the flags, then we can
+ not predict what the next executed instruction will
+ be. Fortunately, this instruction is architecturally
+ forbidden to branch; we know it will fall through.
+ Start by skipping past it. */
+ pc += thumb_insn_size (inst1);
+ itstate = thumb_advance_itstate (itstate);
+
+ /* Set a breakpoint on the following instruction. */
+ gdb_assert ((itstate & 0x0f) != 0);
+ if (insert_bkpt)
+ insert_single_step_breakpoint (gdbarch, aspace, pc);
+ cond_negated = (itstate >> 4) & 1;
+
+ /* Skip all following instructions with the same
+ condition. If there is a later instruction in the IT
+ block with the opposite condition, set the other
+ breakpoint there. If not, then set a breakpoint on
+ the instruction after the IT block. */
+ do
+ {
+ inst1 = read_memory_unsigned_integer (pc, 2, byte_order_for_code);
+ pc += thumb_insn_size (inst1);
+ itstate = thumb_advance_itstate (itstate);
+ }
+ while (itstate != 0 && ((itstate >> 4) & 1) == cond_negated);
+
+ return MAKE_THUMB_ADDR (pc);
+ }
+ }
+ }
+ else if (itstate & 0x0f)
+ {
+ /* We are in a conditional block. Check the condition. */
+ int cond = itstate >> 4;
+
+ if (! condition_true (cond, status))
+ {
+ /* Advance to the next instruction. All the 32-bit
+ instructions share a common prefix. */
+ if ((inst1 & 0xe000) == 0xe000 && (inst1 & 0x1800) != 0)
+ return MAKE_THUMB_ADDR (pc + 4);
+ else
+ return MAKE_THUMB_ADDR (pc + 2);
+ }
+
+ /* Otherwise, handle the instruction normally. */
+ }
+
if ((inst1 & 0xff00) == 0xbd00) /* pop {rlist, pc} */
{
CORE_ADDR sp;
offset = bitcount (bits (inst1, 0, 7)) * INT_REGISTER_SIZE;
sp = get_frame_register_unsigned (frame, ARM_SP_REGNUM);
nextpc = read_memory_unsigned_integer (sp + offset, 4, byte_order);
- nextpc = gdbarch_addr_bits_remove (gdbarch, nextpc);
- if (nextpc == pc)
- error (_("Infinite loop detected"));
}
else if ((inst1 & 0xf000) == 0xd000) /* conditional branch */
{
- unsigned long status = get_frame_register_unsigned (frame, ARM_PS_REGNUM);
unsigned long cond = bits (inst1, 8, 11);
- if (cond != 0x0f && condition_true (cond, status)) /* 0x0f = SWI */
+ if (cond == 0x0f) /* 0x0f = SWI */
+ {
+ struct gdbarch_tdep *tdep;
+ tdep = gdbarch_tdep (gdbarch);
+
+ if (tdep->syscall_next_pc != NULL)
+ nextpc = tdep->syscall_next_pc (frame);
+
+ }
+ else if (cond != 0x0f && condition_true (cond, status))
nextpc = pc_val + (sbits (inst1, 0, 7) << 1);
}
else if ((inst1 & 0xf800) == 0xe000) /* unconditional branch */
{
nextpc = pc_val + (sbits (inst1, 0, 10) << 1);
}
- else if ((inst1 & 0xf800) == 0xf000) /* long branch with link, and blx */
+ else if ((inst1 & 0xe000) == 0xe000) /* 32-bit instruction */
{
unsigned short inst2;
inst2 = read_memory_unsigned_integer (pc + 2, 2, byte_order_for_code);
- offset = (sbits (inst1, 0, 10) << 12) + (bits (inst2, 0, 10) << 1);
- nextpc = pc_val + offset;
- /* For BLX make sure to clear the low bits. */
- if (bits (inst2, 11, 12) == 1)
- nextpc = nextpc & 0xfffffffc;
+
+ /* Default to the next instruction. */
+ nextpc = pc + 4;
+ nextpc = MAKE_THUMB_ADDR (nextpc);
+
+ if ((inst1 & 0xf800) == 0xf000 && (inst2 & 0x8000) == 0x8000)
+ {
+ /* Branches and miscellaneous control instructions. */
+
+ if ((inst2 & 0x1000) != 0 || (inst2 & 0xd001) == 0xc000)
+ {
+ /* B, BL, BLX. */
+ int j1, j2, imm1, imm2;
+
+ imm1 = sbits (inst1, 0, 10);
+ imm2 = bits (inst2, 0, 10);
+ j1 = bit (inst2, 13);
+ j2 = bit (inst2, 11);
+
+ offset = ((imm1 << 12) + (imm2 << 1));
+ offset ^= ((!j2) << 22) | ((!j1) << 23);
+
+ nextpc = pc_val + offset;
+ /* For BLX make sure to clear the low bits. */
+ if (bit (inst2, 12) == 0)
+ nextpc = nextpc & 0xfffffffc;
+ }
+ else if (inst1 == 0xf3de && (inst2 & 0xff00) == 0x3f00)
+ {
+ /* SUBS PC, LR, #imm8. */
+ nextpc = get_frame_register_unsigned (frame, ARM_LR_REGNUM);
+ nextpc -= inst2 & 0x00ff;
+ }
+ else if ((inst2 & 0xd000) == 0x8000 && (inst1 & 0x0380) != 0x0380)
+ {
+ /* Conditional branch. */
+ if (condition_true (bits (inst1, 6, 9), status))
+ {
+ int sign, j1, j2, imm1, imm2;
+
+ sign = sbits (inst1, 10, 10);
+ imm1 = bits (inst1, 0, 5);
+ imm2 = bits (inst2, 0, 10);
+ j1 = bit (inst2, 13);
+ j2 = bit (inst2, 11);
+
+ offset = (sign << 20) + (j2 << 19) + (j1 << 18);
+ offset += (imm1 << 12) + (imm2 << 1);
+
+ nextpc = pc_val + offset;
+ }
+ }
+ }
+ else if ((inst1 & 0xfe50) == 0xe810)
+ {
+ /* Load multiple or RFE. */
+ int rn, offset, load_pc = 1;
+
+ rn = bits (inst1, 0, 3);
+ if (bit (inst1, 7) && !bit (inst1, 8))
+ {
+ /* LDMIA or POP */
+ if (!bit (inst2, 15))
+ load_pc = 0;
+ offset = bitcount (inst2) * 4 - 4;
+ }
+ else if (!bit (inst1, 7) && bit (inst1, 8))
+ {
+ /* LDMDB */
+ if (!bit (inst2, 15))
+ load_pc = 0;
+ offset = -4;
+ }
+ else if (bit (inst1, 7) && bit (inst1, 8))
+ {
+ /* RFEIA */
+ offset = 0;
+ }
+ else if (!bit (inst1, 7) && !bit (inst1, 8))
+ {
+ /* RFEDB */
+ offset = -8;
+ }
+ else
+ load_pc = 0;
+
+ if (load_pc)
+ {
+ CORE_ADDR addr = get_frame_register_unsigned (frame, rn);
+ nextpc = get_frame_memory_unsigned (frame, addr + offset, 4);
+ }
+ }
+ else if ((inst1 & 0xffef) == 0xea4f && (inst2 & 0xfff0) == 0x0f00)
+ {
+ /* MOV PC or MOVS PC. */
+ nextpc = get_frame_register_unsigned (frame, bits (inst2, 0, 3));
+ nextpc = MAKE_THUMB_ADDR (nextpc);
+ }
+ else if ((inst1 & 0xff70) == 0xf850 && (inst2 & 0xf000) == 0xf000)
+ {
+ /* LDR PC. */
+ CORE_ADDR base;
+ int rn, load_pc = 1;
+
+ rn = bits (inst1, 0, 3);
+ base = get_frame_register_unsigned (frame, rn);
+ if (rn == 15)
+ {
+ base = (base + 4) & ~(CORE_ADDR) 0x3;
+ if (bit (inst1, 7))
+ base += bits (inst2, 0, 11);
+ else
+ base -= bits (inst2, 0, 11);
+ }
+ else if (bit (inst1, 7))
+ base += bits (inst2, 0, 11);
+ else if (bit (inst2, 11))
+ {
+ if (bit (inst2, 10))
+ {
+ if (bit (inst2, 9))
+ base += bits (inst2, 0, 7);
+ else
+ base -= bits (inst2, 0, 7);
+ }
+ }
+ else if ((inst2 & 0x0fc0) == 0x0000)
+ {
+ int shift = bits (inst2, 4, 5), rm = bits (inst2, 0, 3);
+ base += get_frame_register_unsigned (frame, rm) << shift;
+ }
+ else
+ /* Reserved. */
+ load_pc = 0;
+
+ if (load_pc)
+ nextpc = get_frame_memory_unsigned (frame, base, 4);
+ }
+ else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf000)
+ {
+ /* TBB. */
+ CORE_ADDR tbl_reg, table, offset, length;
+
+ tbl_reg = bits (inst1, 0, 3);
+ if (tbl_reg == 0x0f)
+ table = pc + 4; /* Regcache copy of PC isn't right yet. */
+ else
+ table = get_frame_register_unsigned (frame, tbl_reg);
+
+ offset = get_frame_register_unsigned (frame, bits (inst2, 0, 3));
+ length = 2 * get_frame_memory_unsigned (frame, table + offset, 1);
+ nextpc = pc_val + length;
+ }
+ else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf010)
+ {
+ /* TBH. */
+ CORE_ADDR tbl_reg, table, offset, length;
+
+ tbl_reg = bits (inst1, 0, 3);
+ if (tbl_reg == 0x0f)
+ table = pc + 4; /* Regcache copy of PC isn't right yet. */
+ else
+ table = get_frame_register_unsigned (frame, tbl_reg);
+
+ offset = 2 * get_frame_register_unsigned (frame, bits (inst2, 0, 3));
+ length = 2 * get_frame_memory_unsigned (frame, table + offset, 2);
+ nextpc = pc_val + length;
+ }
}
else if ((inst1 & 0xff00) == 0x4700) /* bx REG, blx REG */
{
nextpc = pc_val;
else
nextpc = get_frame_register_unsigned (frame, bits (inst1, 3, 6));
-
- nextpc = gdbarch_addr_bits_remove (gdbarch, nextpc);
- if (nextpc == pc)
- error (_("Infinite loop detected"));
}
+ else if ((inst1 & 0xff87) == 0x4687) /* mov pc, REG */
+ {
+ if (bits (inst1, 3, 6) == 0x0f)
+ nextpc = pc_val;
+ else
+ nextpc = get_frame_register_unsigned (frame, bits (inst1, 3, 6));
+ nextpc = MAKE_THUMB_ADDR (nextpc);
+ }
+ else if ((inst1 & 0xf500) == 0xb100)
+ {
+ /* CBNZ or CBZ. */
+ int imm = (bit (inst1, 9) << 6) + (bits (inst1, 3, 7) << 1);
+ ULONGEST reg = get_frame_register_unsigned (frame, bits (inst1, 0, 2));
+
+ if (bit (inst1, 11) && reg != 0)
+ nextpc = pc_val + imm;
+ else if (!bit (inst1, 11) && reg == 0)
+ nextpc = pc_val + imm;
+ }
return nextpc;
}
-CORE_ADDR
-arm_get_next_pc (struct frame_info *frame, CORE_ADDR pc)
+/* Get the raw next address. PC is the current program counter, in
+ FRAME. INSERT_BKPT should be TRUE if we want a breakpoint set on
+ the alternative next instruction if there are two options.
+
+ The value returned has the execution state of the next instruction
+ encoded in it. Use IS_THUMB_ADDR () to see whether the instruction is
+ in Thumb-State, and gdbarch_addr_bits_remove () to get the plain memory
+ address.
+*/
+static CORE_ADDR
+arm_get_next_pc_raw (struct frame_info *frame, CORE_ADDR pc, int insert_bkpt)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
CORE_ADDR nextpc;
if (arm_frame_is_thumb (frame))
- return thumb_get_next_pc (frame, pc);
+ return thumb_get_next_pc_raw (frame, pc, insert_bkpt);
pc_val = (unsigned long) pc;
this_instr = read_memory_unsigned_integer (pc, 4, byte_order_for_code);
/* Branch with Link and change to Thumb. */
nextpc = BranchDest (pc, this_instr);
nextpc |= bit (this_instr, 24) << 1;
-
- nextpc = gdbarch_addr_bits_remove (gdbarch, nextpc);
- if (nextpc == pc)
- error (_("Infinite loop detected"));
+ nextpc = MAKE_THUMB_ADDR (nextpc);
break;
}
case 0xc:
|| bits (this_instr, 4, 27) == 0x12fff3)
{
rn = bits (this_instr, 0, 3);
- result = (rn == 15) ? pc_val + 8
+ nextpc = (rn == 15) ? pc_val + 8
: get_frame_register_unsigned (frame, rn);
- nextpc = (CORE_ADDR) gdbarch_addr_bits_remove
- (gdbarch, result);
-
- if (nextpc == pc)
- error (_("Infinite loop detected"));
-
return nextpc;
}
result = ~operand2;
break;
}
- nextpc = (CORE_ADDR) gdbarch_addr_bits_remove
- (gdbarch, result);
- if (nextpc == pc)
- error (_("Infinite loop detected"));
+ /* In 26-bit APCS the bottom two bits of the result are
+ ignored, and we always end up in ARM state. */
+ if (!arm_apcs_32)
+ nextpc = arm_addr_bits_remove (gdbarch, result);
+ else
+ nextpc = result;
+
break;
}
}
nextpc = (CORE_ADDR) read_memory_integer ((CORE_ADDR) base,
4, byte_order);
-
- nextpc = gdbarch_addr_bits_remove (gdbarch, nextpc);
-
- if (nextpc == pc)
- error (_("Infinite loop detected"));
}
}
break;
else if (bit (this_instr, 24))
offset = -4;
- {
- unsigned long rn_val =
- get_frame_register_unsigned (frame,
- bits (this_instr, 16, 19));
- nextpc =
- (CORE_ADDR) read_memory_integer ((CORE_ADDR) (rn_val
- + offset),
- 4, byte_order);
- }
- nextpc = gdbarch_addr_bits_remove
- (gdbarch, nextpc);
- if (nextpc == pc)
- error (_("Infinite loop detected"));
- }
- }
- break;
+ {
+ unsigned long rn_val =
+ get_frame_register_unsigned (frame,
+ bits (this_instr, 16, 19));
+ nextpc =
+ (CORE_ADDR) read_memory_integer ((CORE_ADDR) (rn_val
+ + offset),
+ 4, byte_order);
+ }
+ }
+ }
+ break;
+
+ case 0xb: /* branch & link */
+ case 0xa: /* branch */
+ {
+ nextpc = BranchDest (pc, this_instr);
+ break;
+ }
+
+ case 0xc:
+ case 0xd:
+ case 0xe: /* coproc ops */
+ break;
+ case 0xf: /* SWI */
+ {
+ struct gdbarch_tdep *tdep;
+ tdep = gdbarch_tdep (gdbarch);
+
+ if (tdep->syscall_next_pc != NULL)
+ nextpc = tdep->syscall_next_pc (frame);
+
+ }
+ break;
+
+ default:
+ fprintf_filtered (gdb_stderr, _("Bad bit-field extraction\n"));
+ return (pc);
+ }
+ }
+
+ return nextpc;
+}
+
+CORE_ADDR
+arm_get_next_pc (struct frame_info *frame, CORE_ADDR pc)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ CORE_ADDR nextpc =
+ gdbarch_addr_bits_remove (gdbarch,
+ arm_get_next_pc_raw (frame, pc, TRUE));
+ if (nextpc == pc)
+ error (_("Infinite loop detected"));
+ return nextpc;
+}
+
+/* single_step() is called just before we want to resume the inferior,
+ if we want to single-step it but there is no hardware or kernel
+ single-step support. We find the target of the coming instruction
+ and breakpoint it. */
+
+int
+arm_software_single_step (struct frame_info *frame)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct address_space *aspace = get_frame_address_space (frame);
+
+ /* NOTE: This may insert the wrong breakpoint instruction when
+ single-stepping over a mode-changing instruction, if the
+ CPSR heuristics are used. */
+
+ CORE_ADDR next_pc = arm_get_next_pc (frame, get_frame_pc (frame));
+ insert_single_step_breakpoint (gdbarch, aspace, next_pc);
+
+ return 1;
+}
+
+/* Given BUF, which is OLD_LEN bytes ending at ENDADDR, expand
+ the buffer to be NEW_LEN bytes ending at ENDADDR. Return
+ NULL if an error occurs. BUF is freed. */
+
+static gdb_byte *
+extend_buffer_earlier (gdb_byte *buf, CORE_ADDR endaddr,
+ int old_len, int new_len)
+{
+ gdb_byte *new_buf, *middle;
+ int bytes_to_read = new_len - old_len;
+
+ new_buf = xmalloc (new_len);
+ memcpy (new_buf + bytes_to_read, buf, old_len);
+ xfree (buf);
+ if (target_read_memory (endaddr - new_len, new_buf, bytes_to_read) != 0)
+ {
+ xfree (new_buf);
+ return NULL;
+ }
+ return new_buf;
+}
+
+/* An IT block is at most the 2-byte IT instruction followed by
+ four 4-byte instructions. The furthest back we must search to
+ find an IT block that affects the current instruction is thus
+ 2 + 3 * 4 == 14 bytes. */
+#define MAX_IT_BLOCK_PREFIX 14
+
+/* Use a quick scan if there are more than this many bytes of
+ code. */
+#define IT_SCAN_THRESHOLD 32
+
+/* Adjust a breakpoint's address to move breakpoints out of IT blocks.
+ A breakpoint in an IT block may not be hit, depending on the
+ condition flags. */
+static CORE_ADDR
+arm_adjust_breakpoint_address (struct gdbarch *gdbarch, CORE_ADDR bpaddr)
+{
+ gdb_byte *buf;
+ char map_type;
+ CORE_ADDR boundary, func_start;
+ int buf_len, buf2_len;
+ enum bfd_endian order = gdbarch_byte_order_for_code (gdbarch);
+ int i, any, last_it, last_it_count;
+
+ /* If we are using BKPT breakpoints, none of this is necessary. */
+ if (gdbarch_tdep (gdbarch)->thumb2_breakpoint == NULL)
+ return bpaddr;
+
+ /* ARM mode does not have this problem. */
+ if (!arm_pc_is_thumb (gdbarch, bpaddr))
+ return bpaddr;
+
+ /* We are setting a breakpoint in Thumb code that could potentially
+ contain an IT block. The first step is to find how much Thumb
+ code there is; we do not need to read outside of known Thumb
+ sequences. */
+ map_type = arm_find_mapping_symbol (bpaddr, &boundary);
+ if (map_type == 0)
+ /* Thumb-2 code must have mapping symbols to have a chance. */
+ return bpaddr;
+
+ bpaddr = gdbarch_addr_bits_remove (gdbarch, bpaddr);
+
+ if (find_pc_partial_function (bpaddr, NULL, &func_start, NULL)
+ && func_start > boundary)
+ boundary = func_start;
+
+ /* Search for a candidate IT instruction. We have to do some fancy
+ footwork to distinguish a real IT instruction from the second
+ half of a 32-bit instruction, but there is no need for that if
+ there's no candidate. */
+ buf_len = min (bpaddr - boundary, MAX_IT_BLOCK_PREFIX);
+ if (buf_len == 0)
+ /* No room for an IT instruction. */
+ return bpaddr;
+
+ buf = xmalloc (buf_len);
+ if (target_read_memory (bpaddr - buf_len, buf, buf_len) != 0)
+ return bpaddr;
+ any = 0;
+ for (i = 0; i < buf_len; i += 2)
+ {
+ unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
+ if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
+ {
+ any = 1;
+ break;
+ }
+ }
+ if (any == 0)
+ {
+ xfree (buf);
+ return bpaddr;
+ }
+
+ /* OK, the code bytes before this instruction contain at least one
+ halfword which resembles an IT instruction. We know that it's
+ Thumb code, but there are still two possibilities. Either the
+ halfword really is an IT instruction, or it is the second half of
+ a 32-bit Thumb instruction. The only way we can tell is to
+ scan forwards from a known instruction boundary. */
+ if (bpaddr - boundary > IT_SCAN_THRESHOLD)
+ {
+ int definite;
+
+ /* There's a lot of code before this instruction. Start with an
+ optimistic search; it's easy to recognize halfwords that can
+ not be the start of a 32-bit instruction, and use that to
+ lock on to the instruction boundaries. */
+ buf = extend_buffer_earlier (buf, bpaddr, buf_len, IT_SCAN_THRESHOLD);
+ if (buf == NULL)
+ return bpaddr;
+ buf_len = IT_SCAN_THRESHOLD;
+
+ definite = 0;
+ for (i = 0; i < buf_len - sizeof (buf) && ! definite; i += 2)
+ {
+ unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
+ if (thumb_insn_size (inst1) == 2)
+ {
+ definite = 1;
+ break;
+ }
+ }
+
+ /* At this point, if DEFINITE, BUF[I] is the first place we
+ are sure that we know the instruction boundaries, and it is far
+ enough from BPADDR that we could not miss an IT instruction
+ affecting BPADDR. If ! DEFINITE, give up - start from a
+ known boundary. */
+ if (! definite)
+ {
+ buf = extend_buffer_earlier (buf, bpaddr, buf_len, bpaddr - boundary);
+ if (buf == NULL)
+ return bpaddr;
+ buf_len = bpaddr - boundary;
+ i = 0;
+ }
+ }
+ else
+ {
+ buf = extend_buffer_earlier (buf, bpaddr, buf_len, bpaddr - boundary);
+ if (buf == NULL)
+ return bpaddr;
+ buf_len = bpaddr - boundary;
+ i = 0;
+ }
+
+ /* Scan forwards. Find the last IT instruction before BPADDR. */
+ last_it = -1;
+ last_it_count = 0;
+ while (i < buf_len)
+ {
+ unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order);
+ last_it_count--;
+ if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
+ {
+ last_it = i;
+ if (inst1 & 0x0001)
+ last_it_count = 4;
+ else if (inst1 & 0x0002)
+ last_it_count = 3;
+ else if (inst1 & 0x0004)
+ last_it_count = 2;
+ else
+ last_it_count = 1;
+ }
+ i += thumb_insn_size (inst1);
+ }
+
+ xfree (buf);
+
+ if (last_it == -1)
+ /* There wasn't really an IT instruction after all. */
+ return bpaddr;
+
+ if (last_it_count < 1)
+ /* It was too far away. */
+ return bpaddr;
+
+ /* This really is a trouble spot. Move the breakpoint to the IT
+ instruction. */
+ return bpaddr - buf_len + last_it;
+}
+
+/* ARM displaced stepping support.
+
+ Generally ARM displaced stepping works as follows:
+
+ 1. When an instruction is to be single-stepped, it is first decoded by
+ arm_process_displaced_insn (called from arm_displaced_step_copy_insn).
+ Depending on the type of instruction, it is then copied to a scratch
+ location, possibly in a modified form. The copy_* set of functions
+ performs such modification, as necessary. A breakpoint is placed after
+ the modified instruction in the scratch space to return control to GDB.
+ Note in particular that instructions which modify the PC will no longer
+ do so after modification.
+
+ 2. The instruction is single-stepped, by setting the PC to the scratch
+ location address, and resuming. Control returns to GDB when the
+ breakpoint is hit.
+
+ 3. A cleanup function (cleanup_*) is called corresponding to the copy_*
+ function used for the current instruction. This function's job is to
+ put the CPU/memory state back to what it would have been if the
+ instruction had been executed unmodified in its original location. */
+
+/* NOP instruction (mov r0, r0). */
+#define ARM_NOP 0xe1a00000
+
+/* Helper for register reads for displaced stepping. In particular, this
+ returns the PC as it would be seen by the instruction at its original
+ location. */
+
+ULONGEST
+displaced_read_reg (struct regcache *regs, CORE_ADDR from, int regno)
+{
+ ULONGEST ret;
+
+ if (regno == 15)
+ {
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: read pc value %.8lx\n",
+ (unsigned long) from + 8);
+ return (ULONGEST) from + 8; /* Pipeline offset. */
+ }
+ else
+ {
+ regcache_cooked_read_unsigned (regs, regno, &ret);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: read r%d value %.8lx\n",
+ regno, (unsigned long) ret);
+ return ret;
+ }
+}
+
+static int
+displaced_in_arm_mode (struct regcache *regs)
+{
+ ULONGEST ps;
+ ULONGEST t_bit = arm_psr_thumb_bit (get_regcache_arch (regs));
+
+ regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps);
+
+ return (ps & t_bit) == 0;
+}
+
+/* Write to the PC as from a branch instruction. */
+
+static void
+branch_write_pc (struct regcache *regs, ULONGEST val)
+{
+ if (displaced_in_arm_mode (regs))
+ /* Note: If bits 0/1 are set, this branch would be unpredictable for
+ architecture versions < 6. */
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & ~(ULONGEST) 0x3);
+ else
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & ~(ULONGEST) 0x1);
+}
+
+/* Write to the PC as from a branch-exchange instruction. */
+
+static void
+bx_write_pc (struct regcache *regs, ULONGEST val)
+{
+ ULONGEST ps;
+ ULONGEST t_bit = arm_psr_thumb_bit (get_regcache_arch (regs));
+
+ regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps);
+
+ if ((val & 1) == 1)
+ {
+ regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps | t_bit);
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffe);
+ }
+ else if ((val & 2) == 0)
+ {
+ regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps & ~t_bit);
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val);
+ }
+ else
+ {
+ /* Unpredictable behaviour. Try to do something sensible (switch to ARM
+ mode, align dest to 4 bytes). */
+ warning (_("Single-stepping BX to non-word-aligned ARM instruction."));
+ regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps & ~t_bit);
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffc);
+ }
+}
+
+/* Write to the PC as if from a load instruction. */
+
+static void
+load_write_pc (struct regcache *regs, ULONGEST val)
+{
+ if (DISPLACED_STEPPING_ARCH_VERSION >= 5)
+ bx_write_pc (regs, val);
+ else
+ branch_write_pc (regs, val);
+}
+
+/* Write to the PC as if from an ALU instruction. */
+
+static void
+alu_write_pc (struct regcache *regs, ULONGEST val)
+{
+ if (DISPLACED_STEPPING_ARCH_VERSION >= 7 && displaced_in_arm_mode (regs))
+ bx_write_pc (regs, val);
+ else
+ branch_write_pc (regs, val);
+}
+
+/* Helper for writing to registers for displaced stepping. Writing to the PC
+ has a varying effects depending on the instruction which does the write:
+ this is controlled by the WRITE_PC argument. */
+
+void
+displaced_write_reg (struct regcache *regs, struct displaced_step_closure *dsc,
+ int regno, ULONGEST val, enum pc_write_style write_pc)
+{
+ if (regno == 15)
+ {
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: writing pc %.8lx\n",
+ (unsigned long) val);
+ switch (write_pc)
+ {
+ case BRANCH_WRITE_PC:
+ branch_write_pc (regs, val);
+ break;
+
+ case BX_WRITE_PC:
+ bx_write_pc (regs, val);
+ break;
+
+ case LOAD_WRITE_PC:
+ load_write_pc (regs, val);
+ break;
+
+ case ALU_WRITE_PC:
+ alu_write_pc (regs, val);
+ break;
+
+ case CANNOT_WRITE_PC:
+ warning (_("Instruction wrote to PC in an unexpected way when "
+ "single-stepping"));
+ break;
+
+ default:
+ internal_error (__FILE__, __LINE__,
+ _("Invalid argument to displaced_write_reg"));
+ }
+
+ dsc->wrote_to_pc = 1;
+ }
+ else
+ {
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: writing r%d value %.8lx\n",
+ regno, (unsigned long) val);
+ regcache_cooked_write_unsigned (regs, regno, val);
+ }
+}
+
+/* This function is used to concisely determine if an instruction INSN
+ references PC. Register fields of interest in INSN should have the
+ corresponding fields of BITMASK set to 0b1111. The function returns return 1
+ if any of these fields in INSN reference the PC (also 0b1111, r15), else it
+ returns 0. */
+
+static int
+insn_references_pc (uint32_t insn, uint32_t bitmask)
+{
+ uint32_t lowbit = 1;
+
+ while (bitmask != 0)
+ {
+ uint32_t mask;
+
+ for (; lowbit && (bitmask & lowbit) == 0; lowbit <<= 1)
+ ;
+
+ if (!lowbit)
+ break;
+
+ mask = lowbit * 0xf;
+
+ if ((insn & mask) == mask)
+ return 1;
+
+ bitmask &= ~mask;
+ }
+
+ return 0;
+}
+
+/* The simplest copy function. Many instructions have the same effect no
+ matter what address they are executed at: in those cases, use this. */
+
+static int
+copy_unmodified (struct gdbarch *gdbarch, uint32_t insn,
+ const char *iname, struct displaced_step_closure *dsc)
+{
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying insn %.8lx, "
+ "opcode/class '%s' unmodified\n", (unsigned long) insn,
+ iname);
+
+ dsc->modinsn[0] = insn;
+
+ return 0;
+}
+
+/* Preload instructions with immediate offset. */
+
+static void
+cleanup_preload (struct gdbarch *gdbarch,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
+ if (!dsc->u.preload.immed)
+ displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
+}
+
+static int
+copy_preload (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int rn = bits (insn, 16, 19);
+ ULONGEST rn_val;
+ CORE_ADDR from = dsc->insn_addr;
+
+ if (!insn_references_pc (insn, 0x000f0000ul))
+ return copy_unmodified (gdbarch, insn, "preload", dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying preload insn %.8lx\n",
+ (unsigned long) insn);
+
+ /* Preload instructions:
+
+ {pli/pld} [rn, #+/-imm]
+ ->
+ {pli/pld} [r0, #+/-imm]. */
+
+ dsc->tmp[0] = displaced_read_reg (regs, from, 0);
+ rn_val = displaced_read_reg (regs, from, rn);
+ displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
+
+ dsc->u.preload.immed = 1;
+
+ dsc->modinsn[0] = insn & 0xfff0ffff;
+
+ dsc->cleanup = &cleanup_preload;
+
+ return 0;
+}
+
+/* Preload instructions with register offset. */
+
+static int
+copy_preload_reg (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int rn = bits (insn, 16, 19);
+ unsigned int rm = bits (insn, 0, 3);
+ ULONGEST rn_val, rm_val;
+ CORE_ADDR from = dsc->insn_addr;
+
+ if (!insn_references_pc (insn, 0x000f000ful))
+ return copy_unmodified (gdbarch, insn, "preload reg", dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying preload insn %.8lx\n",
+ (unsigned long) insn);
+
+ /* Preload register-offset instructions:
+
+ {pli/pld} [rn, rm {, shift}]
+ ->
+ {pli/pld} [r0, r1 {, shift}]. */
+
+ dsc->tmp[0] = displaced_read_reg (regs, from, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, from, 1);
+ rn_val = displaced_read_reg (regs, from, rn);
+ rm_val = displaced_read_reg (regs, from, rm);
+ displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, rm_val, CANNOT_WRITE_PC);
+
+ dsc->u.preload.immed = 0;
+
+ dsc->modinsn[0] = (insn & 0xfff0fff0) | 0x1;
+
+ dsc->cleanup = &cleanup_preload;
+
+ return 0;
+}
+
+/* Copy/cleanup coprocessor load and store instructions. */
+
+static void
+cleanup_copro_load_store (struct gdbarch *gdbarch,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ ULONGEST rn_val = displaced_read_reg (regs, dsc->insn_addr, 0);
+
+ displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
+
+ if (dsc->u.ldst.writeback)
+ displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, LOAD_WRITE_PC);
+}
+
+static int
+copy_copro_load_store (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int rn = bits (insn, 16, 19);
+ ULONGEST rn_val;
+ CORE_ADDR from = dsc->insn_addr;
+
+ if (!insn_references_pc (insn, 0x000f0000ul))
+ return copy_unmodified (gdbarch, insn, "copro load/store", dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying coprocessor "
+ "load/store insn %.8lx\n", (unsigned long) insn);
+
+ /* Coprocessor load/store instructions:
+
+ {stc/stc2} [<Rn>, #+/-imm] (and other immediate addressing modes)
+ ->
+ {stc/stc2} [r0, #+/-imm].
+
+ ldc/ldc2 are handled identically. */
+
+ dsc->tmp[0] = displaced_read_reg (regs, from, 0);
+ rn_val = displaced_read_reg (regs, from, rn);
+ displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC);
+
+ dsc->u.ldst.writeback = bit (insn, 25);
+ dsc->u.ldst.rn = rn;
+
+ dsc->modinsn[0] = insn & 0xfff0ffff;
+
+ dsc->cleanup = &cleanup_copro_load_store;
+
+ return 0;
+}
+
+/* Clean up branch instructions (actually perform the branch, by setting
+ PC). */
+
+static void
+cleanup_branch (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ ULONGEST from = dsc->insn_addr;
+ uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
+ int branch_taken = condition_true (dsc->u.branch.cond, status);
+ enum pc_write_style write_pc = dsc->u.branch.exchange
+ ? BX_WRITE_PC : BRANCH_WRITE_PC;
+
+ if (!branch_taken)
+ return;
+
+ if (dsc->u.branch.link)
+ {
+ ULONGEST pc = displaced_read_reg (regs, from, 15);
+ displaced_write_reg (regs, dsc, 14, pc - 4, CANNOT_WRITE_PC);
+ }
+
+ displaced_write_reg (regs, dsc, 15, dsc->u.branch.dest, write_pc);
+}
+
+/* Copy B/BL/BLX instructions with immediate destinations. */
+
+static int
+copy_b_bl_blx (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ unsigned int cond = bits (insn, 28, 31);
+ int exchange = (cond == 0xf);
+ int link = exchange || bit (insn, 24);
+ CORE_ADDR from = dsc->insn_addr;
+ long offset;
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying %s immediate insn "
+ "%.8lx\n", (exchange) ? "blx" : (link) ? "bl" : "b",
+ (unsigned long) insn);
+
+ /* Implement "BL<cond> <label>" as:
+
+ Preparation: cond <- instruction condition
+ Insn: mov r0, r0 (nop)
+ Cleanup: if (condition true) { r14 <- pc; pc <- label }.
+
+ B<cond> similar, but don't set r14 in cleanup. */
+
+ if (exchange)
+ /* For BLX, set bit 0 of the destination. The cleanup_branch function will
+ then arrange the switch into Thumb mode. */
+ offset = (bits (insn, 0, 23) << 2) | (bit (insn, 24) << 1) | 1;
+ else
+ offset = bits (insn, 0, 23) << 2;
+
+ if (bit (offset, 25))
+ offset = offset | ~0x3ffffff;
+
+ dsc->u.branch.cond = cond;
+ dsc->u.branch.link = link;
+ dsc->u.branch.exchange = exchange;
+ dsc->u.branch.dest = from + 8 + offset;
+
+ dsc->modinsn[0] = ARM_NOP;
+
+ dsc->cleanup = &cleanup_branch;
+
+ return 0;
+}
+
+/* Copy BX/BLX with register-specified destinations. */
+
+static int
+copy_bx_blx_reg (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ unsigned int cond = bits (insn, 28, 31);
+ /* BX: x12xxx1x
+ BLX: x12xxx3x. */
+ int link = bit (insn, 5);
+ unsigned int rm = bits (insn, 0, 3);
+ CORE_ADDR from = dsc->insn_addr;
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying %s register insn "
+ "%.8lx\n", (link) ? "blx" : "bx", (unsigned long) insn);
+
+ /* Implement {BX,BLX}<cond> <reg>" as:
+
+ Preparation: cond <- instruction condition
+ Insn: mov r0, r0 (nop)
+ Cleanup: if (condition true) { r14 <- pc; pc <- dest; }.
+
+ Don't set r14 in cleanup for BX. */
+
+ dsc->u.branch.dest = displaced_read_reg (regs, from, rm);
+
+ dsc->u.branch.cond = cond;
+ dsc->u.branch.link = link;
+ dsc->u.branch.exchange = 1;
+
+ dsc->modinsn[0] = ARM_NOP;
+
+ dsc->cleanup = &cleanup_branch;
+
+ return 0;
+}
+
+/* Copy/cleanup arithmetic/logic instruction with immediate RHS. */
+
+static void
+cleanup_alu_imm (struct gdbarch *gdbarch,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ ULONGEST rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
+ displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
+}
+
+static int
+copy_alu_imm (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int rn = bits (insn, 16, 19);
+ unsigned int rd = bits (insn, 12, 15);
+ unsigned int op = bits (insn, 21, 24);
+ int is_mov = (op == 0xd);
+ ULONGEST rd_val, rn_val;
+ CORE_ADDR from = dsc->insn_addr;
+
+ if (!insn_references_pc (insn, 0x000ff000ul))
+ return copy_unmodified (gdbarch, insn, "ALU immediate", dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying immediate %s insn "
+ "%.8lx\n", is_mov ? "move" : "ALU",
+ (unsigned long) insn);
+
+ /* Instruction is of form:
+
+ <op><cond> rd, [rn,] #imm
+
+ Rewrite as:
+
+ Preparation: tmp1, tmp2 <- r0, r1;
+ r0, r1 <- rd, rn
+ Insn: <op><cond> r0, r1, #imm
+ Cleanup: rd <- r0; r0 <- tmp1; r1 <- tmp2
+ */
+
+ dsc->tmp[0] = displaced_read_reg (regs, from, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, from, 1);
+ rn_val = displaced_read_reg (regs, from, rn);
+ rd_val = displaced_read_reg (regs, from, rd);
+ displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
+ dsc->rd = rd;
+
+ if (is_mov)
+ dsc->modinsn[0] = insn & 0xfff00fff;
+ else
+ dsc->modinsn[0] = (insn & 0xfff00fff) | 0x10000;
+
+ dsc->cleanup = &cleanup_alu_imm;
+
+ return 0;
+}
+
+/* Copy/cleanup arithmetic/logic insns with register RHS. */
+
+static void
+cleanup_alu_reg (struct gdbarch *gdbarch,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ ULONGEST rd_val;
+ int i;
+
+ rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
+
+ for (i = 0; i < 3; i++)
+ displaced_write_reg (regs, dsc, i, dsc->tmp[i], CANNOT_WRITE_PC);
+
+ displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
+}
+
+static int
+copy_alu_reg (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int rn = bits (insn, 16, 19);
+ unsigned int rm = bits (insn, 0, 3);
+ unsigned int rd = bits (insn, 12, 15);
+ unsigned int op = bits (insn, 21, 24);
+ int is_mov = (op == 0xd);
+ ULONGEST rd_val, rn_val, rm_val;
+ CORE_ADDR from = dsc->insn_addr;
+
+ if (!insn_references_pc (insn, 0x000ff00ful))
+ return copy_unmodified (gdbarch, insn, "ALU reg", dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying reg %s insn %.8lx\n",
+ is_mov ? "move" : "ALU", (unsigned long) insn);
+
+ /* Instruction is of form:
+
+ <op><cond> rd, [rn,] rm [, <shift>]
+
+ Rewrite as:
+
+ Preparation: tmp1, tmp2, tmp3 <- r0, r1, r2;
+ r0, r1, r2 <- rd, rn, rm
+ Insn: <op><cond> r0, r1, r2 [, <shift>]
+ Cleanup: rd <- r0; r0, r1, r2 <- tmp1, tmp2, tmp3
+ */
+
+ dsc->tmp[0] = displaced_read_reg (regs, from, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, from, 1);
+ dsc->tmp[2] = displaced_read_reg (regs, from, 2);
+ rd_val = displaced_read_reg (regs, from, rd);
+ rn_val = displaced_read_reg (regs, from, rn);
+ rm_val = displaced_read_reg (regs, from, rm);
+ displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC);
+ dsc->rd = rd;
+
+ if (is_mov)
+ dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x2;
+ else
+ dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x10002;
+
+ dsc->cleanup = &cleanup_alu_reg;
+
+ return 0;
+}
+
+/* Cleanup/copy arithmetic/logic insns with shifted register RHS. */
+
+static void
+cleanup_alu_shifted_reg (struct gdbarch *gdbarch,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ ULONGEST rd_val = displaced_read_reg (regs, dsc->insn_addr, 0);
+ int i;
+
+ for (i = 0; i < 4; i++)
+ displaced_write_reg (regs, dsc, i, dsc->tmp[i], CANNOT_WRITE_PC);
+
+ displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC);
+}
+
+static int
+copy_alu_shifted_reg (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ unsigned int rn = bits (insn, 16, 19);
+ unsigned int rm = bits (insn, 0, 3);
+ unsigned int rd = bits (insn, 12, 15);
+ unsigned int rs = bits (insn, 8, 11);
+ unsigned int op = bits (insn, 21, 24);
+ int is_mov = (op == 0xd), i;
+ ULONGEST rd_val, rn_val, rm_val, rs_val;
+ CORE_ADDR from = dsc->insn_addr;
+
+ if (!insn_references_pc (insn, 0x000fff0ful))
+ return copy_unmodified (gdbarch, insn, "ALU shifted reg", dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying shifted reg %s insn "
+ "%.8lx\n", is_mov ? "move" : "ALU",
+ (unsigned long) insn);
+
+ /* Instruction is of form:
+
+ <op><cond> rd, [rn,] rm, <shift> rs
+
+ Rewrite as:
+
+ Preparation: tmp1, tmp2, tmp3, tmp4 <- r0, r1, r2, r3
+ r0, r1, r2, r3 <- rd, rn, rm, rs
+ Insn: <op><cond> r0, r1, r2, <shift> r3
+ Cleanup: tmp5 <- r0
+ r0, r1, r2, r3 <- tmp1, tmp2, tmp3, tmp4
+ rd <- tmp5
+ */
+
+ for (i = 0; i < 4; i++)
+ dsc->tmp[i] = displaced_read_reg (regs, from, i);
+
+ rd_val = displaced_read_reg (regs, from, rd);
+ rn_val = displaced_read_reg (regs, from, rn);
+ rm_val = displaced_read_reg (regs, from, rm);
+ rs_val = displaced_read_reg (regs, from, rs);
+ displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 3, rs_val, CANNOT_WRITE_PC);
+ dsc->rd = rd;
+
+ if (is_mov)
+ dsc->modinsn[0] = (insn & 0xfff000f0) | 0x302;
+ else
+ dsc->modinsn[0] = (insn & 0xfff000f0) | 0x10302;
+
+ dsc->cleanup = &cleanup_alu_shifted_reg;
+
+ return 0;
+}
+
+/* Clean up load instructions. */
+
+static void
+cleanup_load (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ ULONGEST rt_val, rt_val2 = 0, rn_val;
+ CORE_ADDR from = dsc->insn_addr;
+
+ rt_val = displaced_read_reg (regs, from, 0);
+ if (dsc->u.ldst.xfersize == 8)
+ rt_val2 = displaced_read_reg (regs, from, 1);
+ rn_val = displaced_read_reg (regs, from, 2);
+
+ displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
+ if (dsc->u.ldst.xfersize > 4)
+ displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, dsc->tmp[2], CANNOT_WRITE_PC);
+ if (!dsc->u.ldst.immed)
+ displaced_write_reg (regs, dsc, 3, dsc->tmp[3], CANNOT_WRITE_PC);
+
+ /* Handle register writeback. */
+ if (dsc->u.ldst.writeback)
+ displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, CANNOT_WRITE_PC);
+ /* Put result in right place. */
+ displaced_write_reg (regs, dsc, dsc->rd, rt_val, LOAD_WRITE_PC);
+ if (dsc->u.ldst.xfersize == 8)
+ displaced_write_reg (regs, dsc, dsc->rd + 1, rt_val2, LOAD_WRITE_PC);
+}
+
+/* Clean up store instructions. */
+
+static void
+cleanup_store (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ CORE_ADDR from = dsc->insn_addr;
+ ULONGEST rn_val = displaced_read_reg (regs, from, 2);
+
+ displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC);
+ if (dsc->u.ldst.xfersize > 4)
+ displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, dsc->tmp[2], CANNOT_WRITE_PC);
+ if (!dsc->u.ldst.immed)
+ displaced_write_reg (regs, dsc, 3, dsc->tmp[3], CANNOT_WRITE_PC);
+ if (!dsc->u.ldst.restore_r4)
+ displaced_write_reg (regs, dsc, 4, dsc->tmp[4], CANNOT_WRITE_PC);
+
+ /* Writeback. */
+ if (dsc->u.ldst.writeback)
+ displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, CANNOT_WRITE_PC);
+}
+
+/* Copy "extra" load/store instructions. These are halfword/doubleword
+ transfers, which have a different encoding to byte/word transfers. */
+
+static int
+copy_extra_ld_st (struct gdbarch *gdbarch, uint32_t insn, int unpriveleged,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ unsigned int op1 = bits (insn, 20, 24);
+ unsigned int op2 = bits (insn, 5, 6);
+ unsigned int rt = bits (insn, 12, 15);
+ unsigned int rn = bits (insn, 16, 19);
+ unsigned int rm = bits (insn, 0, 3);
+ char load[12] = {0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1};
+ char bytesize[12] = {2, 2, 2, 2, 8, 1, 8, 1, 8, 2, 8, 2};
+ int immed = (op1 & 0x4) != 0;
+ int opcode;
+ ULONGEST rt_val, rt_val2 = 0, rn_val, rm_val = 0;
+ CORE_ADDR from = dsc->insn_addr;
+
+ if (!insn_references_pc (insn, 0x000ff00ful))
+ return copy_unmodified (gdbarch, insn, "extra load/store", dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying %sextra load/store "
+ "insn %.8lx\n", unpriveleged ? "unpriveleged " : "",
+ (unsigned long) insn);
+
+ opcode = ((op2 << 2) | (op1 & 0x1) | ((op1 & 0x4) >> 1)) - 4;
+
+ if (opcode < 0)
+ internal_error (__FILE__, __LINE__,
+ _("copy_extra_ld_st: instruction decode error"));
+
+ dsc->tmp[0] = displaced_read_reg (regs, from, 0);
+ dsc->tmp[1] = displaced_read_reg (regs, from, 1);
+ dsc->tmp[2] = displaced_read_reg (regs, from, 2);
+ if (!immed)
+ dsc->tmp[3] = displaced_read_reg (regs, from, 3);
+
+ rt_val = displaced_read_reg (regs, from, rt);
+ if (bytesize[opcode] == 8)
+ rt_val2 = displaced_read_reg (regs, from, rt + 1);
+ rn_val = displaced_read_reg (regs, from, rn);
+ if (!immed)
+ rm_val = displaced_read_reg (regs, from, rm);
+
+ displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC);
+ if (bytesize[opcode] == 8)
+ displaced_write_reg (regs, dsc, 1, rt_val2, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, rn_val, CANNOT_WRITE_PC);
+ if (!immed)
+ displaced_write_reg (regs, dsc, 3, rm_val, CANNOT_WRITE_PC);
+
+ dsc->rd = rt;
+ dsc->u.ldst.xfersize = bytesize[opcode];
+ dsc->u.ldst.rn = rn;
+ dsc->u.ldst.immed = immed;
+ dsc->u.ldst.writeback = bit (insn, 24) == 0 || bit (insn, 21) != 0;
+ dsc->u.ldst.restore_r4 = 0;
+
+ if (immed)
+ /* {ldr,str}<width><cond> rt, [rt2,] [rn, #imm]
+ ->
+ {ldr,str}<width><cond> r0, [r1,] [r2, #imm]. */
+ dsc->modinsn[0] = (insn & 0xfff00fff) | 0x20000;
+ else
+ /* {ldr,str}<width><cond> rt, [rt2,] [rn, +/-rm]
+ ->
+ {ldr,str}<width><cond> r0, [r1,] [r2, +/-r3]. */
+ dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x20003;
+
+ dsc->cleanup = load[opcode] ? &cleanup_load : &cleanup_store;
+
+ return 0;
+}
+
+/* Copy byte/word loads and stores. */
+
+static int
+copy_ldr_str_ldrb_strb (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc, int load, int byte,
+ int usermode)
+{
+ int immed = !bit (insn, 25);
+ unsigned int rt = bits (insn, 12, 15);
+ unsigned int rn = bits (insn, 16, 19);
+ unsigned int rm = bits (insn, 0, 3); /* Only valid if !immed. */
+ ULONGEST rt_val, rn_val, rm_val = 0;
+ CORE_ADDR from = dsc->insn_addr;
+
+ if (!insn_references_pc (insn, 0x000ff00ful))
+ return copy_unmodified (gdbarch, insn, "load/store", dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying %s%s insn %.8lx\n",
+ load ? (byte ? "ldrb" : "ldr")
+ : (byte ? "strb" : "str"), usermode ? "t" : "",
+ (unsigned long) insn);
+
+ dsc->tmp[0] = displaced_read_reg (regs, from, 0);
+ dsc->tmp[2] = displaced_read_reg (regs, from, 2);
+ if (!immed)
+ dsc->tmp[3] = displaced_read_reg (regs, from, 3);
+ if (!load)
+ dsc->tmp[4] = displaced_read_reg (regs, from, 4);
+
+ rt_val = displaced_read_reg (regs, from, rt);
+ rn_val = displaced_read_reg (regs, from, rn);
+ if (!immed)
+ rm_val = displaced_read_reg (regs, from, rm);
+
+ displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, 2, rn_val, CANNOT_WRITE_PC);
+ if (!immed)
+ displaced_write_reg (regs, dsc, 3, rm_val, CANNOT_WRITE_PC);
+
+ dsc->rd = rt;
+ dsc->u.ldst.xfersize = byte ? 1 : 4;
+ dsc->u.ldst.rn = rn;
+ dsc->u.ldst.immed = immed;
+ dsc->u.ldst.writeback = bit (insn, 24) == 0 || bit (insn, 21) != 0;
+
+ /* To write PC we can do:
+
+ scratch+0: str pc, temp (*temp = scratch + 8 + offset)
+ scratch+4: ldr r4, temp
+ scratch+8: sub r4, r4, pc (r4 = scratch + 8 + offset - scratch - 8 - 8)
+ scratch+12: add r4, r4, #8 (r4 = offset)
+ scratch+16: add r0, r0, r4
+ scratch+20: str r0, [r2, #imm] (or str r0, [r2, r3])
+ scratch+24: <temp>
+
+ Otherwise we don't know what value to write for PC, since the offset is
+ architecture-dependent (sometimes PC+8, sometimes PC+12). */
+
+ if (load || rt != 15)
+ {
+ dsc->u.ldst.restore_r4 = 0;
+
+ if (immed)
+ /* {ldr,str}[b]<cond> rt, [rn, #imm], etc.
+ ->
+ {ldr,str}[b]<cond> r0, [r2, #imm]. */
+ dsc->modinsn[0] = (insn & 0xfff00fff) | 0x20000;
+ else
+ /* {ldr,str}[b]<cond> rt, [rn, rm], etc.
+ ->
+ {ldr,str}[b]<cond> r0, [r2, r3]. */
+ dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x20003;
+ }
+ else
+ {
+ /* We need to use r4 as scratch. Make sure it's restored afterwards. */
+ dsc->u.ldst.restore_r4 = 1;
+
+ dsc->modinsn[0] = 0xe58ff014; /* str pc, [pc, #20]. */
+ dsc->modinsn[1] = 0xe59f4010; /* ldr r4, [pc, #16]. */
+ dsc->modinsn[2] = 0xe044400f; /* sub r4, r4, pc. */
+ dsc->modinsn[3] = 0xe2844008; /* add r4, r4, #8. */
+ dsc->modinsn[4] = 0xe0800004; /* add r0, r0, r4. */
+
+ /* As above. */
+ if (immed)
+ dsc->modinsn[5] = (insn & 0xfff00fff) | 0x20000;
+ else
+ dsc->modinsn[5] = (insn & 0xfff00ff0) | 0x20003;
+
+ dsc->modinsn[6] = 0x0; /* breakpoint location. */
+ dsc->modinsn[7] = 0x0; /* scratch space. */
+
+ dsc->numinsns = 6;
+ }
+
+ dsc->cleanup = load ? &cleanup_load : &cleanup_store;
+
+ return 0;
+}
+
+/* Cleanup LDM instructions with fully-populated register list. This is an
+ unfortunate corner case: it's impossible to implement correctly by modifying
+ the instruction. The issue is as follows: we have an instruction,
+
+ ldm rN, {r0-r15}
+
+ which we must rewrite to avoid loading PC. A possible solution would be to
+ do the load in two halves, something like (with suitable cleanup
+ afterwards):
+
+ mov r8, rN
+ ldm[id][ab] r8!, {r0-r7}
+ str r7, <temp>
+ ldm[id][ab] r8, {r7-r14}
+ <bkpt>
+
+ but at present there's no suitable place for <temp>, since the scratch space
+ is overwritten before the cleanup routine is called. For now, we simply
+ emulate the instruction. */
+
+static void
+cleanup_block_load_all (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ ULONGEST from = dsc->insn_addr;
+ int inc = dsc->u.block.increment;
+ int bump_before = dsc->u.block.before ? (inc ? 4 : -4) : 0;
+ int bump_after = dsc->u.block.before ? 0 : (inc ? 4 : -4);
+ uint32_t regmask = dsc->u.block.regmask;
+ int regno = inc ? 0 : 15;
+ CORE_ADDR xfer_addr = dsc->u.block.xfer_addr;
+ int exception_return = dsc->u.block.load && dsc->u.block.user
+ && (regmask & 0x8000) != 0;
+ uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
+ int do_transfer = condition_true (dsc->u.block.cond, status);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
+ if (!do_transfer)
+ return;
+
+ /* If the instruction is ldm rN, {...pc}^, I don't think there's anything
+ sensible we can do here. Complain loudly. */
+ if (exception_return)
+ error (_("Cannot single-step exception return"));
+
+ /* We don't handle any stores here for now. */
+ gdb_assert (dsc->u.block.load != 0);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: emulating block transfer: "
+ "%s %s %s\n", dsc->u.block.load ? "ldm" : "stm",
+ dsc->u.block.increment ? "inc" : "dec",
+ dsc->u.block.before ? "before" : "after");
+
+ while (regmask)
+ {
+ uint32_t memword;
+
+ if (inc)
+ while (regno <= 15 && (regmask & (1 << regno)) == 0)
+ regno++;
+ else
+ while (regno >= 0 && (regmask & (1 << regno)) == 0)
+ regno--;
+
+ xfer_addr += bump_before;
+
+ memword = read_memory_unsigned_integer (xfer_addr, 4, byte_order);
+ displaced_write_reg (regs, dsc, regno, memword, LOAD_WRITE_PC);
+
+ xfer_addr += bump_after;
+
+ regmask &= ~(1 << regno);
+ }
+
+ if (dsc->u.block.writeback)
+ displaced_write_reg (regs, dsc, dsc->u.block.rn, xfer_addr,
+ CANNOT_WRITE_PC);
+}
+
+/* Clean up an STM which included the PC in the register list. */
+
+static void
+cleanup_block_store_pc (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ ULONGEST from = dsc->insn_addr;
+ uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
+ int store_executed = condition_true (dsc->u.block.cond, status);
+ CORE_ADDR pc_stored_at, transferred_regs = bitcount (dsc->u.block.regmask);
+ CORE_ADDR stm_insn_addr;
+ uint32_t pc_val;
+ long offset;
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
+ /* If condition code fails, there's nothing else to do. */
+ if (!store_executed)
+ return;
+
+ if (dsc->u.block.increment)
+ {
+ pc_stored_at = dsc->u.block.xfer_addr + 4 * transferred_regs;
+
+ if (dsc->u.block.before)
+ pc_stored_at += 4;
+ }
+ else
+ {
+ pc_stored_at = dsc->u.block.xfer_addr;
+
+ if (dsc->u.block.before)
+ pc_stored_at -= 4;
+ }
+
+ pc_val = read_memory_unsigned_integer (pc_stored_at, 4, byte_order);
+ stm_insn_addr = dsc->scratch_base;
+ offset = pc_val - stm_insn_addr;
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: detected PC offset %.8lx for "
+ "STM instruction\n", offset);
+
+ /* Rewrite the stored PC to the proper value for the non-displaced original
+ instruction. */
+ write_memory_unsigned_integer (pc_stored_at, 4, byte_order,
+ dsc->insn_addr + offset);
+}
+
+/* Clean up an LDM which includes the PC in the register list. We clumped all
+ the registers in the transferred list into a contiguous range r0...rX (to
+ avoid loading PC directly and losing control of the debugged program), so we
+ must undo that here. */
+
+static void
+cleanup_block_load_pc (struct gdbarch *gdbarch,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ ULONGEST from = dsc->insn_addr;
+ uint32_t status = displaced_read_reg (regs, from, ARM_PS_REGNUM);
+ int load_executed = condition_true (dsc->u.block.cond, status), i;
+ unsigned int mask = dsc->u.block.regmask, write_reg = 15;
+ unsigned int regs_loaded = bitcount (mask);
+ unsigned int num_to_shuffle = regs_loaded, clobbered;
+
+ /* The method employed here will fail if the register list is fully populated
+ (we need to avoid loading PC directly). */
+ gdb_assert (num_to_shuffle < 16);
+
+ if (!load_executed)
+ return;
+
+ clobbered = (1 << num_to_shuffle) - 1;
+
+ while (num_to_shuffle > 0)
+ {
+ if ((mask & (1 << write_reg)) != 0)
+ {
+ unsigned int read_reg = num_to_shuffle - 1;
+
+ if (read_reg != write_reg)
+ {
+ ULONGEST rval = displaced_read_reg (regs, from, read_reg);
+ displaced_write_reg (regs, dsc, write_reg, rval, LOAD_WRITE_PC);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: move "
+ "loaded register r%d to r%d\n"), read_reg,
+ write_reg);
+ }
+ else if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: register "
+ "r%d already in the right place\n"),
+ write_reg);
+
+ clobbered &= ~(1 << write_reg);
+
+ num_to_shuffle--;
+ }
+
+ write_reg--;
+ }
+
+ /* Restore any registers we scribbled over. */
+ for (write_reg = 0; clobbered != 0; write_reg++)
+ {
+ if ((clobbered & (1 << write_reg)) != 0)
+ {
+ displaced_write_reg (regs, dsc, write_reg, dsc->tmp[write_reg],
+ CANNOT_WRITE_PC);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, _("displaced: LDM: restored "
+ "clobbered register r%d\n"), write_reg);
+ clobbered &= ~(1 << write_reg);
+ }
+ }
+
+ /* Perform register writeback manually. */
+ if (dsc->u.block.writeback)
+ {
+ ULONGEST new_rn_val = dsc->u.block.xfer_addr;
+
+ if (dsc->u.block.increment)
+ new_rn_val += regs_loaded * 4;
+ else
+ new_rn_val -= regs_loaded * 4;
+
+ displaced_write_reg (regs, dsc, dsc->u.block.rn, new_rn_val,
+ CANNOT_WRITE_PC);
+ }
+}
+
+/* Handle ldm/stm, apart from some tricky cases which are unlikely to occur
+ in user-level code (in particular exception return, ldm rn, {...pc}^). */
+
+static int
+copy_block_xfer (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ int load = bit (insn, 20);
+ int user = bit (insn, 22);
+ int increment = bit (insn, 23);
+ int before = bit (insn, 24);
+ int writeback = bit (insn, 21);
+ int rn = bits (insn, 16, 19);
+ CORE_ADDR from = dsc->insn_addr;
+
+ /* Block transfers which don't mention PC can be run directly out-of-line. */
+ if (rn != 15 && (insn & 0x8000) == 0)
+ return copy_unmodified (gdbarch, insn, "ldm/stm", dsc);
+
+ if (rn == 15)
+ {
+ warning (_("displaced: Unpredictable LDM or STM with base register r15"));
+ return copy_unmodified (gdbarch, insn, "unpredictable ldm/stm", dsc);
+ }
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying block transfer insn "
+ "%.8lx\n", (unsigned long) insn);
+
+ dsc->u.block.xfer_addr = displaced_read_reg (regs, from, rn);
+ dsc->u.block.rn = rn;
+
+ dsc->u.block.load = load;
+ dsc->u.block.user = user;
+ dsc->u.block.increment = increment;
+ dsc->u.block.before = before;
+ dsc->u.block.writeback = writeback;
+ dsc->u.block.cond = bits (insn, 28, 31);
+
+ dsc->u.block.regmask = insn & 0xffff;
+
+ if (load)
+ {
+ if ((insn & 0xffff) == 0xffff)
+ {
+ /* LDM with a fully-populated register list. This case is
+ particularly tricky. Implement for now by fully emulating the
+ instruction (which might not behave perfectly in all cases, but
+ these instructions should be rare enough for that not to matter
+ too much). */
+ dsc->modinsn[0] = ARM_NOP;
+
+ dsc->cleanup = &cleanup_block_load_all;
+ }
+ else
+ {
+ /* LDM of a list of registers which includes PC. Implement by
+ rewriting the list of registers to be transferred into a
+ contiguous chunk r0...rX before doing the transfer, then shuffling
+ registers into the correct places in the cleanup routine. */
+ unsigned int regmask = insn & 0xffff;
+ unsigned int num_in_list = bitcount (regmask), new_regmask, bit = 1;
+ unsigned int to = 0, from = 0, i, new_rn;
+
+ for (i = 0; i < num_in_list; i++)
+ dsc->tmp[i] = displaced_read_reg (regs, from, i);
+
+ /* Writeback makes things complicated. We need to avoid clobbering
+ the base register with one of the registers in our modified
+ register list, but just using a different register can't work in
+ all cases, e.g.:
+
+ ldm r14!, {r0-r13,pc}
+
+ which would need to be rewritten as:
+
+ ldm rN!, {r0-r14}
+
+ but that can't work, because there's no free register for N.
+
+ Solve this by turning off the writeback bit, and emulating
+ writeback manually in the cleanup routine. */
+
+ if (writeback)
+ insn &= ~(1 << 21);
+
+ new_regmask = (1 << num_in_list) - 1;
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, _("displaced: LDM r%d%s, "
+ "{..., pc}: original reg list %.4x, modified "
+ "list %.4x\n"), rn, writeback ? "!" : "",
+ (int) insn & 0xffff, new_regmask);
+
+ dsc->modinsn[0] = (insn & ~0xffff) | (new_regmask & 0xffff);
+
+ dsc->cleanup = &cleanup_block_load_pc;
+ }
+ }
+ else
+ {
+ /* STM of a list of registers which includes PC. Run the instruction
+ as-is, but out of line: this will store the wrong value for the PC,
+ so we must manually fix up the memory in the cleanup routine.
+ Doing things this way has the advantage that we can auto-detect
+ the offset of the PC write (which is architecture-dependent) in
+ the cleanup routine. */
+ dsc->modinsn[0] = insn;
+
+ dsc->cleanup = &cleanup_block_store_pc;
+ }
+
+ return 0;
+}
+
+/* Cleanup/copy SVC (SWI) instructions. These two functions are overridden
+ for Linux, where some SVC instructions must be treated specially. */
+
+static void
+cleanup_svc (struct gdbarch *gdbarch, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ CORE_ADDR from = dsc->insn_addr;
+ CORE_ADDR resume_addr = from + 4;
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: cleanup for svc, resume at "
+ "%.8lx\n", (unsigned long) resume_addr);
+
+ displaced_write_reg (regs, dsc, ARM_PC_REGNUM, resume_addr, BRANCH_WRITE_PC);
+}
+
+static int
+copy_svc (struct gdbarch *gdbarch, uint32_t insn, CORE_ADDR to,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ CORE_ADDR from = dsc->insn_addr;
+
+ /* Allow OS-specific code to override SVC handling. */
+ if (dsc->u.svc.copy_svc_os)
+ return dsc->u.svc.copy_svc_os (gdbarch, insn, to, regs, dsc);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying svc insn %.8lx\n",
+ (unsigned long) insn);
+
+ /* Preparation: none.
+ Insn: unmodified svc.
+ Cleanup: pc <- insn_addr + 4. */
+
+ dsc->modinsn[0] = insn;
+
+ dsc->cleanup = &cleanup_svc;
+ /* Pretend we wrote to the PC, so cleanup doesn't set PC to the next
+ instruction. */
+ dsc->wrote_to_pc = 1;
+
+ return 0;
+}
+
+/* Copy undefined instructions. */
+
+static int
+copy_undef (struct gdbarch *gdbarch, uint32_t insn,
+ struct displaced_step_closure *dsc)
+{
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying undefined insn %.8lx\n",
+ (unsigned long) insn);
+
+ dsc->modinsn[0] = insn;
+
+ return 0;
+}
+
+/* Copy unpredictable instructions. */
+
+static int
+copy_unpred (struct gdbarch *gdbarch, uint32_t insn,
+ struct displaced_step_closure *dsc)
+{
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying unpredictable insn "
+ "%.8lx\n", (unsigned long) insn);
+
+ dsc->modinsn[0] = insn;
+
+ return 0;
+}
+
+/* The decode_* functions are instruction decoding helpers. They mostly follow
+ the presentation in the ARM ARM. */
+
+static int
+decode_misc_memhint_neon (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ unsigned int op1 = bits (insn, 20, 26), op2 = bits (insn, 4, 7);
+ unsigned int rn = bits (insn, 16, 19);
+
+ if (op1 == 0x10 && (op2 & 0x2) == 0x0 && (rn & 0xe) == 0x0)
+ return copy_unmodified (gdbarch, insn, "cps", dsc);
+ else if (op1 == 0x10 && op2 == 0x0 && (rn & 0xe) == 0x1)
+ return copy_unmodified (gdbarch, insn, "setend", dsc);
+ else if ((op1 & 0x60) == 0x20)
+ return copy_unmodified (gdbarch, insn, "neon dataproc", dsc);
+ else if ((op1 & 0x71) == 0x40)
+ return copy_unmodified (gdbarch, insn, "neon elt/struct load/store", dsc);
+ else if ((op1 & 0x77) == 0x41)
+ return copy_unmodified (gdbarch, insn, "unallocated mem hint", dsc);
+ else if ((op1 & 0x77) == 0x45)
+ return copy_preload (gdbarch, insn, regs, dsc); /* pli. */
+ else if ((op1 & 0x77) == 0x51)
+ {
+ if (rn != 0xf)
+ return copy_preload (gdbarch, insn, regs, dsc); /* pld/pldw. */
+ else
+ return copy_unpred (gdbarch, insn, dsc);
+ }
+ else if ((op1 & 0x77) == 0x55)
+ return copy_preload (gdbarch, insn, regs, dsc); /* pld/pldw. */
+ else if (op1 == 0x57)
+ switch (op2)
+ {
+ case 0x1: return copy_unmodified (gdbarch, insn, "clrex", dsc);
+ case 0x4: return copy_unmodified (gdbarch, insn, "dsb", dsc);
+ case 0x5: return copy_unmodified (gdbarch, insn, "dmb", dsc);
+ case 0x6: return copy_unmodified (gdbarch, insn, "isb", dsc);
+ default: return copy_unpred (gdbarch, insn, dsc);
+ }
+ else if ((op1 & 0x63) == 0x43)
+ return copy_unpred (gdbarch, insn, dsc);
+ else if ((op2 & 0x1) == 0x0)
+ switch (op1 & ~0x80)
+ {
+ case 0x61:
+ return copy_unmodified (gdbarch, insn, "unallocated mem hint", dsc);
+ case 0x65:
+ return copy_preload_reg (gdbarch, insn, regs, dsc); /* pli reg. */
+ case 0x71: case 0x75:
+ /* pld/pldw reg. */
+ return copy_preload_reg (gdbarch, insn, regs, dsc);
+ case 0x63: case 0x67: case 0x73: case 0x77:
+ return copy_unpred (gdbarch, insn, dsc);
+ default:
+ return copy_undef (gdbarch, insn, dsc);
+ }
+ else
+ return copy_undef (gdbarch, insn, dsc); /* Probably unreachable. */
+}
+
+static int
+decode_unconditional (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ if (bit (insn, 27) == 0)
+ return decode_misc_memhint_neon (gdbarch, insn, regs, dsc);
+ /* Switch on bits: 0bxxxxx321xxx0xxxxxxxxxxxxxxxxxxxx. */
+ else switch (((insn & 0x7000000) >> 23) | ((insn & 0x100000) >> 20))
+ {
+ case 0x0: case 0x2:
+ return copy_unmodified (gdbarch, insn, "srs", dsc);
+
+ case 0x1: case 0x3:
+ return copy_unmodified (gdbarch, insn, "rfe", dsc);
+
+ case 0x4: case 0x5: case 0x6: case 0x7:
+ return copy_b_bl_blx (gdbarch, insn, regs, dsc);
+
+ case 0x8:
+ switch ((insn & 0xe00000) >> 21)
+ {
+ case 0x1: case 0x3: case 0x4: case 0x5: case 0x6: case 0x7:
+ /* stc/stc2. */
+ return copy_copro_load_store (gdbarch, insn, regs, dsc);
+
+ case 0x2:
+ return copy_unmodified (gdbarch, insn, "mcrr/mcrr2", dsc);
+
+ default:
+ return copy_undef (gdbarch, insn, dsc);
+ }
+
+ case 0x9:
+ {
+ int rn_f = (bits (insn, 16, 19) == 0xf);
+ switch ((insn & 0xe00000) >> 21)
+ {
+ case 0x1: case 0x3:
+ /* ldc/ldc2 imm (undefined for rn == pc). */
+ return rn_f ? copy_undef (gdbarch, insn, dsc)
+ : copy_copro_load_store (gdbarch, insn, regs, dsc);
+
+ case 0x2:
+ return copy_unmodified (gdbarch, insn, "mrrc/mrrc2", dsc);
+
+ case 0x4: case 0x5: case 0x6: case 0x7:
+ /* ldc/ldc2 lit (undefined for rn != pc). */
+ return rn_f ? copy_copro_load_store (gdbarch, insn, regs, dsc)
+ : copy_undef (gdbarch, insn, dsc);
+
+ default:
+ return copy_undef (gdbarch, insn, dsc);
+ }
+ }
+
+ case 0xa:
+ return copy_unmodified (gdbarch, insn, "stc/stc2", dsc);
+
+ case 0xb:
+ if (bits (insn, 16, 19) == 0xf)
+ /* ldc/ldc2 lit. */
+ return copy_copro_load_store (gdbarch, insn, regs, dsc);
+ else
+ return copy_undef (gdbarch, insn, dsc);
+
+ case 0xc:
+ if (bit (insn, 4))
+ return copy_unmodified (gdbarch, insn, "mcr/mcr2", dsc);
+ else
+ return copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
+
+ case 0xd:
+ if (bit (insn, 4))
+ return copy_unmodified (gdbarch, insn, "mrc/mrc2", dsc);
+ else
+ return copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
+
+ default:
+ return copy_undef (gdbarch, insn, dsc);
+ }
+}
+
+/* Decode miscellaneous instructions in dp/misc encoding space. */
+
+static int
+decode_miscellaneous (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ unsigned int op2 = bits (insn, 4, 6);
+ unsigned int op = bits (insn, 21, 22);
+ unsigned int op1 = bits (insn, 16, 19);
+
+ switch (op2)
+ {
+ case 0x0:
+ return copy_unmodified (gdbarch, insn, "mrs/msr", dsc);
+
+ case 0x1:
+ if (op == 0x1) /* bx. */
+ return copy_bx_blx_reg (gdbarch, insn, regs, dsc);
+ else if (op == 0x3)
+ return copy_unmodified (gdbarch, insn, "clz", dsc);
+ else
+ return copy_undef (gdbarch, insn, dsc);
+
+ case 0x2:
+ if (op == 0x1)
+ /* Not really supported. */
+ return copy_unmodified (gdbarch, insn, "bxj", dsc);
+ else
+ return copy_undef (gdbarch, insn, dsc);
+
+ case 0x3:
+ if (op == 0x1)
+ return copy_bx_blx_reg (gdbarch, insn, regs, dsc); /* blx register. */
+ else
+ return copy_undef (gdbarch, insn, dsc);
+
+ case 0x5:
+ return copy_unmodified (gdbarch, insn, "saturating add/sub", dsc);
+
+ case 0x7:
+ if (op == 0x1)
+ return copy_unmodified (gdbarch, insn, "bkpt", dsc);
+ else if (op == 0x3)
+ /* Not really supported. */
+ return copy_unmodified (gdbarch, insn, "smc", dsc);
+
+ default:
+ return copy_undef (gdbarch, insn, dsc);
+ }
+}
+
+static int
+decode_dp_misc (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ if (bit (insn, 25))
+ switch (bits (insn, 20, 24))
+ {
+ case 0x10:
+ return copy_unmodified (gdbarch, insn, "movw", dsc);
+
+ case 0x14:
+ return copy_unmodified (gdbarch, insn, "movt", dsc);
+
+ case 0x12: case 0x16:
+ return copy_unmodified (gdbarch, insn, "msr imm", dsc);
+
+ default:
+ return copy_alu_imm (gdbarch, insn, regs, dsc);
+ }
+ else
+ {
+ uint32_t op1 = bits (insn, 20, 24), op2 = bits (insn, 4, 7);
+
+ if ((op1 & 0x19) != 0x10 && (op2 & 0x1) == 0x0)
+ return copy_alu_reg (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x19) != 0x10 && (op2 & 0x9) == 0x1)
+ return copy_alu_shifted_reg (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x19) == 0x10 && (op2 & 0x8) == 0x0)
+ return decode_miscellaneous (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x19) == 0x10 && (op2 & 0x9) == 0x8)
+ return copy_unmodified (gdbarch, insn, "halfword mul/mla", dsc);
+ else if ((op1 & 0x10) == 0x00 && op2 == 0x9)
+ return copy_unmodified (gdbarch, insn, "mul/mla", dsc);
+ else if ((op1 & 0x10) == 0x10 && op2 == 0x9)
+ return copy_unmodified (gdbarch, insn, "synch", dsc);
+ else if (op2 == 0xb || (op2 & 0xd) == 0xd)
+ /* 2nd arg means "unpriveleged". */
+ return copy_extra_ld_st (gdbarch, insn, (op1 & 0x12) == 0x02, regs,
+ dsc);
+ }
+
+ /* Should be unreachable. */
+ return 1;
+}
+
+static int
+decode_ld_st_word_ubyte (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ int a = bit (insn, 25), b = bit (insn, 4);
+ uint32_t op1 = bits (insn, 20, 24);
+ int rn_f = bits (insn, 16, 19) == 0xf;
+
+ if ((!a && (op1 & 0x05) == 0x00 && (op1 & 0x17) != 0x02)
+ || (a && (op1 & 0x05) == 0x00 && (op1 & 0x17) != 0x02 && !b))
+ return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 0, 0);
+ else if ((!a && (op1 & 0x17) == 0x02)
+ || (a && (op1 & 0x17) == 0x02 && !b))
+ return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 0, 1);
+ else if ((!a && (op1 & 0x05) == 0x01 && (op1 & 0x17) != 0x03)
+ || (a && (op1 & 0x05) == 0x01 && (op1 & 0x17) != 0x03 && !b))
+ return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 0, 0);
+ else if ((!a && (op1 & 0x17) == 0x03)
+ || (a && (op1 & 0x17) == 0x03 && !b))
+ return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 0, 1);
+ else if ((!a && (op1 & 0x05) == 0x04 && (op1 & 0x17) != 0x06)
+ || (a && (op1 & 0x05) == 0x04 && (op1 & 0x17) != 0x06 && !b))
+ return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 1, 0);
+ else if ((!a && (op1 & 0x17) == 0x06)
+ || (a && (op1 & 0x17) == 0x06 && !b))
+ return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 1, 1);
+ else if ((!a && (op1 & 0x05) == 0x05 && (op1 & 0x17) != 0x07)
+ || (a && (op1 & 0x05) == 0x05 && (op1 & 0x17) != 0x07 && !b))
+ return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 1, 0);
+ else if ((!a && (op1 & 0x17) == 0x07)
+ || (a && (op1 & 0x17) == 0x07 && !b))
+ return copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 1, 1);
+
+ /* Should be unreachable. */
+ return 1;
+}
+
+static int
+decode_media (struct gdbarch *gdbarch, uint32_t insn,
+ struct displaced_step_closure *dsc)
+{
+ switch (bits (insn, 20, 24))
+ {
+ case 0x00: case 0x01: case 0x02: case 0x03:
+ return copy_unmodified (gdbarch, insn, "parallel add/sub signed", dsc);
+
+ case 0x04: case 0x05: case 0x06: case 0x07:
+ return copy_unmodified (gdbarch, insn, "parallel add/sub unsigned", dsc);
+
+ case 0x08: case 0x09: case 0x0a: case 0x0b:
+ case 0x0c: case 0x0d: case 0x0e: case 0x0f:
+ return copy_unmodified (gdbarch, insn,
+ "decode/pack/unpack/saturate/reverse", dsc);
+
+ case 0x18:
+ if (bits (insn, 5, 7) == 0) /* op2. */
+ {
+ if (bits (insn, 12, 15) == 0xf)
+ return copy_unmodified (gdbarch, insn, "usad8", dsc);
+ else
+ return copy_unmodified (gdbarch, insn, "usada8", dsc);
+ }
+ else
+ return copy_undef (gdbarch, insn, dsc);
+
+ case 0x1a: case 0x1b:
+ if (bits (insn, 5, 6) == 0x2) /* op2[1:0]. */
+ return copy_unmodified (gdbarch, insn, "sbfx", dsc);
+ else
+ return copy_undef (gdbarch, insn, dsc);
+
+ case 0x1c: case 0x1d:
+ if (bits (insn, 5, 6) == 0x0) /* op2[1:0]. */
+ {
+ if (bits (insn, 0, 3) == 0xf)
+ return copy_unmodified (gdbarch, insn, "bfc", dsc);
+ else
+ return copy_unmodified (gdbarch, insn, "bfi", dsc);
+ }
+ else
+ return copy_undef (gdbarch, insn, dsc);
+
+ case 0x1e: case 0x1f:
+ if (bits (insn, 5, 6) == 0x2) /* op2[1:0]. */
+ return copy_unmodified (gdbarch, insn, "ubfx", dsc);
+ else
+ return copy_undef (gdbarch, insn, dsc);
+ }
+
+ /* Should be unreachable. */
+ return 1;
+}
+
+static int
+decode_b_bl_ldmstm (struct gdbarch *gdbarch, int32_t insn,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ if (bit (insn, 25))
+ return copy_b_bl_blx (gdbarch, insn, regs, dsc);
+ else
+ return copy_block_xfer (gdbarch, insn, regs, dsc);
+}
+
+static int
+decode_ext_reg_ld_st (struct gdbarch *gdbarch, uint32_t insn,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ unsigned int opcode = bits (insn, 20, 24);
+
+ switch (opcode)
+ {
+ case 0x04: case 0x05: /* VFP/Neon mrrc/mcrr. */
+ return copy_unmodified (gdbarch, insn, "vfp/neon mrrc/mcrr", dsc);
+
+ case 0x08: case 0x0a: case 0x0c: case 0x0e:
+ case 0x12: case 0x16:
+ return copy_unmodified (gdbarch, insn, "vfp/neon vstm/vpush", dsc);
+
+ case 0x09: case 0x0b: case 0x0d: case 0x0f:
+ case 0x13: case 0x17:
+ return copy_unmodified (gdbarch, insn, "vfp/neon vldm/vpop", dsc);
+
+ case 0x10: case 0x14: case 0x18: case 0x1c: /* vstr. */
+ case 0x11: case 0x15: case 0x19: case 0x1d: /* vldr. */
+ /* Note: no writeback for these instructions. Bit 25 will always be
+ zero though (via caller), so the following works OK. */
+ return copy_copro_load_store (gdbarch, insn, regs, dsc);
+ }
+
+ /* Should be unreachable. */
+ return 1;
+}
+
+static int
+decode_svc_copro (struct gdbarch *gdbarch, uint32_t insn, CORE_ADDR to,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ unsigned int op1 = bits (insn, 20, 25);
+ int op = bit (insn, 4);
+ unsigned int coproc = bits (insn, 8, 11);
+ unsigned int rn = bits (insn, 16, 19);
+
+ if ((op1 & 0x20) == 0x00 && (op1 & 0x3a) != 0x00 && (coproc & 0xe) == 0xa)
+ return decode_ext_reg_ld_st (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x21) == 0x00 && (op1 & 0x3a) != 0x00
+ && (coproc & 0xe) != 0xa)
+ /* stc/stc2. */
+ return copy_copro_load_store (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x21) == 0x01 && (op1 & 0x3a) != 0x00
+ && (coproc & 0xe) != 0xa)
+ /* ldc/ldc2 imm/lit. */
+ return copy_copro_load_store (gdbarch, insn, regs, dsc);
+ else if ((op1 & 0x3e) == 0x00)
+ return copy_undef (gdbarch, insn, dsc);
+ else if ((op1 & 0x3e) == 0x04 && (coproc & 0xe) == 0xa)
+ return copy_unmodified (gdbarch, insn, "neon 64bit xfer", dsc);
+ else if (op1 == 0x04 && (coproc & 0xe) != 0xa)
+ return copy_unmodified (gdbarch, insn, "mcrr/mcrr2", dsc);
+ else if (op1 == 0x05 && (coproc & 0xe) != 0xa)
+ return copy_unmodified (gdbarch, insn, "mrrc/mrrc2", dsc);
+ else if ((op1 & 0x30) == 0x20 && !op)
+ {
+ if ((coproc & 0xe) == 0xa)
+ return copy_unmodified (gdbarch, insn, "vfp dataproc", dsc);
+ else
+ return copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc);
+ }
+ else if ((op1 & 0x30) == 0x20 && op)
+ return copy_unmodified (gdbarch, insn, "neon 8/16/32 bit xfer", dsc);
+ else if ((op1 & 0x31) == 0x20 && op && (coproc & 0xe) != 0xa)
+ return copy_unmodified (gdbarch, insn, "mcr/mcr2", dsc);
+ else if ((op1 & 0x31) == 0x21 && op && (coproc & 0xe) != 0xa)
+ return copy_unmodified (gdbarch, insn, "mrc/mrc2", dsc);
+ else if ((op1 & 0x30) == 0x30)
+ return copy_svc (gdbarch, insn, to, regs, dsc);
+ else
+ return copy_undef (gdbarch, insn, dsc); /* Possibly unreachable. */
+}
+
+void
+arm_process_displaced_insn (struct gdbarch *gdbarch, uint32_t insn,
+ CORE_ADDR from, CORE_ADDR to, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ int err = 0;
+
+ if (!displaced_in_arm_mode (regs))
+ error (_("Displaced stepping is only supported in ARM mode"));
+
+ /* Most displaced instructions use a 1-instruction scratch space, so set this
+ here and override below if/when necessary. */
+ dsc->numinsns = 1;
+ dsc->insn_addr = from;
+ dsc->scratch_base = to;
+ dsc->cleanup = NULL;
+ dsc->wrote_to_pc = 0;
+
+ if ((insn & 0xf0000000) == 0xf0000000)
+ err = decode_unconditional (gdbarch, insn, regs, dsc);
+ else switch (((insn & 0x10) >> 4) | ((insn & 0xe000000) >> 24))
+ {
+ case 0x0: case 0x1: case 0x2: case 0x3:
+ err = decode_dp_misc (gdbarch, insn, regs, dsc);
+ break;
+
+ case 0x4: case 0x5: case 0x6:
+ err = decode_ld_st_word_ubyte (gdbarch, insn, regs, dsc);
+ break;
- case 0xb: /* branch & link */
- case 0xa: /* branch */
- {
- nextpc = BranchDest (pc, this_instr);
+ case 0x7:
+ err = decode_media (gdbarch, insn, dsc);
+ break;
- nextpc = gdbarch_addr_bits_remove (gdbarch, nextpc);
- if (nextpc == pc)
- error (_("Infinite loop detected"));
- break;
- }
+ case 0x8: case 0x9: case 0xa: case 0xb:
+ err = decode_b_bl_ldmstm (gdbarch, insn, regs, dsc);
+ break;
- case 0xc:
- case 0xd:
- case 0xe: /* coproc ops */
- case 0xf: /* SWI */
- break;
+ case 0xc: case 0xd: case 0xe: case 0xf:
+ err = decode_svc_copro (gdbarch, insn, to, regs, dsc);
+ break;
+ }
- default:
- fprintf_filtered (gdb_stderr, _("Bad bit-field extraction\n"));
- return (pc);
- }
+ if (err)
+ internal_error (__FILE__, __LINE__,
+ _("arm_process_displaced_insn: Instruction decode error"));
+}
+
+/* Actually set up the scratch space for a displaced instruction. */
+
+void
+arm_displaced_init_closure (struct gdbarch *gdbarch, CORE_ADDR from,
+ CORE_ADDR to, struct displaced_step_closure *dsc)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ unsigned int i;
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+
+ /* Poke modified instruction(s). */
+ for (i = 0; i < dsc->numinsns; i++)
+ {
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: writing insn %.8lx at "
+ "%.8lx\n", (unsigned long) dsc->modinsn[i],
+ (unsigned long) to + i * 4);
+ write_memory_unsigned_integer (to + i * 4, 4, byte_order_for_code,
+ dsc->modinsn[i]);
}
- return nextpc;
+ /* Put breakpoint afterwards. */
+ write_memory (to + dsc->numinsns * 4, tdep->arm_breakpoint,
+ tdep->arm_breakpoint_size);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copy %s->%s: ",
+ paddress (gdbarch, from), paddress (gdbarch, to));
}
-/* single_step() is called just before we want to resume the inferior,
- if we want to single-step it but there is no hardware or kernel
- single-step support. We find the target of the coming instruction
- and breakpoint it. */
+/* Entry point for copying an instruction into scratch space for displaced
+ stepping. */
-int
-arm_software_single_step (struct frame_info *frame)
+struct displaced_step_closure *
+arm_displaced_step_copy_insn (struct gdbarch *gdbarch,
+ CORE_ADDR from, CORE_ADDR to,
+ struct regcache *regs)
{
- struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct displaced_step_closure *dsc
+ = xmalloc (sizeof (struct displaced_step_closure));
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ uint32_t insn = read_memory_unsigned_integer (from, 4, byte_order_for_code);
- /* NOTE: This may insert the wrong breakpoint instruction when
- single-stepping over a mode-changing instruction, if the
- CPSR heuristics are used. */
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: stepping insn %.8lx "
+ "at %.8lx\n", (unsigned long) insn,
+ (unsigned long) from);
- CORE_ADDR next_pc = arm_get_next_pc (frame, get_frame_pc (frame));
- insert_single_step_breakpoint (gdbarch, next_pc);
+ arm_process_displaced_insn (gdbarch, insn, from, to, regs, dsc);
+ arm_displaced_init_closure (gdbarch, from, to, dsc);
- return 1;
+ return dsc;
+}
+
+/* Entry point for cleaning things up after a displaced instruction has been
+ single-stepped. */
+
+void
+arm_displaced_step_fixup (struct gdbarch *gdbarch,
+ struct displaced_step_closure *dsc,
+ CORE_ADDR from, CORE_ADDR to,
+ struct regcache *regs)
+{
+ if (dsc->cleanup)
+ dsc->cleanup (gdbarch, regs, dsc);
+
+ if (!dsc->wrote_to_pc)
+ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, dsc->insn_addr + 4);
}
#include "bfd-in2.h"
static int
gdb_print_insn_arm (bfd_vma memaddr, disassemble_info *info)
{
- if (arm_pc_is_thumb (memaddr))
+ struct gdbarch *gdbarch = info->application_data;
+
+ if (arm_pc_is_thumb (gdbarch, memaddr))
{
static asymbol *asym;
static combined_entry_type ce;
arm_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr, int *lenptr)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
- if (arm_pc_is_thumb (*pcptr))
+ if (arm_pc_is_thumb (gdbarch, *pcptr))
{
*pcptr = UNMAKE_THUMB_ADDR (*pcptr);
+
+ /* If we have a separate 32-bit breakpoint instruction for Thumb-2,
+ check whether we are replacing a 32-bit instruction. */
+ if (tdep->thumb2_breakpoint != NULL)
+ {
+ gdb_byte buf[2];
+ if (target_read_memory (*pcptr, buf, 2) == 0)
+ {
+ unsigned short inst1;
+ inst1 = extract_unsigned_integer (buf, 2, byte_order_for_code);
+ if ((inst1 & 0xe000) == 0xe000 && (inst1 & 0x1800) != 0)
+ {
+ *lenptr = tdep->thumb2_breakpoint_size;
+ return tdep->thumb2_breakpoint;
+ }
+ }
+ }
+
*lenptr = tdep->thumb_breakpoint_size;
return tdep->thumb_breakpoint;
}
}
}
+static void
+arm_remote_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr,
+ int *kindptr)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ arm_breakpoint_from_pc (gdbarch, pcptr, kindptr);
+
+ if (arm_pc_is_thumb (gdbarch, *pcptr) && *kindptr == 4)
+ /* The documented magic value for a 32-bit Thumb-2 breakpoint, so
+ that this is not confused with a 32-bit ARM breakpoint. */
+ *kindptr = 3;
+}
+
/* Extract from an array REGBUF containing the (raw) register state a
function return value of type TYPE, and copy that, in virtual
format, into VALBUF. */
/* If PC is in a Thumb call or return stub, return the address of the
target PC, which is in a register. The thunk functions are called
_call_via_xx, where x is the register name. The possible names
- are r0-r9, sl, fp, ip, sp, and lr. */
- if (strncmp (name, "_call_via_", 10) == 0)
+ are r0-r9, sl, fp, ip, sp, and lr. ARM RealView has similar
+ functions, named __ARM_call_via_r[0-7]. */
+ if (strncmp (name, "_call_via_", 10) == 0
+ || strncmp (name, "__ARM_call_via_", strlen ("__ARM_call_via_")) == 0)
{
/* Use the name suffix to determine which register contains the
target PC. */
static int
coff_sym_is_thumb (int val)
{
- return (val == C_THUMBEXT ||
- val == C_THUMBSTAT ||
- val == C_THUMBEXTFUNC ||
- val == C_THUMBSTATFUNC ||
- val == C_THUMBLABEL);
+ return (val == C_THUMBEXT
+ || val == C_THUMBSTAT
+ || val == C_THUMBEXTFUNC
+ || val == C_THUMBSTATFUNC
+ || val == C_THUMBLABEL);
}
/* arm_coff_make_msymbol_special()
}
static void
-arm_objfile_data_cleanup (struct objfile *objfile, void *arg)
+arm_objfile_data_free (struct objfile *objfile, void *arg)
{
struct arm_per_objfile *data = arg;
unsigned int i;
static void
arm_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
regcache_cooked_write_unsigned (regcache, ARM_PC_REGNUM, pc);
/* If necessary, set the T bit. */
if (arm_apcs_32)
{
- ULONGEST val;
+ ULONGEST val, t_bit;
regcache_cooked_read_unsigned (regcache, ARM_PS_REGNUM, &val);
- if (arm_pc_is_thumb (pc))
- regcache_cooked_write_unsigned (regcache, ARM_PS_REGNUM, val | CPSR_T);
+ t_bit = arm_psr_thumb_bit (gdbarch);
+ if (arm_pc_is_thumb (gdbarch, pc))
+ regcache_cooked_write_unsigned (regcache, ARM_PS_REGNUM,
+ val | t_bit);
else
regcache_cooked_write_unsigned (regcache, ARM_PS_REGNUM,
- val & ~(ULONGEST) CPSR_T);
+ val & ~t_bit);
}
}
else
offset = 0;
- regcache_raw_write (regcache, double_regnum, buf + offset);
- offset = 8 - offset;
- regcache_raw_write (regcache, double_regnum + 1, buf + offset);
-}
+ regcache_raw_write (regcache, double_regnum, buf + offset);
+ offset = 8 - offset;
+ regcache_raw_write (regcache, double_regnum + 1, buf + offset);
+}
+
+static void
+arm_pseudo_write (struct gdbarch *gdbarch, struct regcache *regcache,
+ int regnum, const gdb_byte *buf)
+{
+ const int num_regs = gdbarch_num_regs (gdbarch);
+ char name_buf[4];
+ gdb_byte reg_buf[8];
+ int offset, double_regnum;
+
+ gdb_assert (regnum >= num_regs);
+ regnum -= num_regs;
+
+ if (gdbarch_tdep (gdbarch)->have_neon_pseudos && regnum >= 32 && regnum < 48)
+ /* Quad-precision register. */
+ arm_neon_quad_write (gdbarch, regcache, regnum - 32, buf);
+ else
+ {
+ /* Single-precision register. */
+ gdb_assert (regnum < 32);
+
+ /* s0 is always the least significant half of d0. */
+ if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
+ offset = (regnum & 1) ? 0 : 4;
+ else
+ offset = (regnum & 1) ? 4 : 0;
+
+ sprintf (name_buf, "d%d", regnum >> 1);
+ double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
+ strlen (name_buf));
+
+ regcache_raw_read (regcache, double_regnum, reg_buf);
+ memcpy (reg_buf + offset, buf, 4);
+ regcache_raw_write (regcache, double_regnum, reg_buf);
+ }
+}
+
+static struct value *
+value_of_arm_user_reg (struct frame_info *frame, const void *baton)
+{
+ const int *reg_p = baton;
+ return value_of_register (*reg_p, frame);
+}
+\f
+static enum gdb_osabi
+arm_elf_osabi_sniffer (bfd *abfd)
+{
+ unsigned int elfosabi;
+ enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
+
+ elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
+
+ if (elfosabi == ELFOSABI_ARM)
+ /* GNU tools use this value. Check note sections in this case,
+ as well. */
+ bfd_map_over_sections (abfd,
+ generic_elf_osabi_sniff_abi_tag_sections,
+ &osabi);
+
+ /* Anything else will be handled by the generic ELF sniffer. */
+ return osabi;
+}
+
+\f
+/* Initialize the current architecture based on INFO. If possible,
+ re-use an architecture from ARCHES, which is a list of
+ architectures already created during this debugging session.
+
+ Called e.g. at program startup, when reading a core file, and when
+ reading a binary file. */
+
+static struct gdbarch *
+arm_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
+{
+ struct gdbarch_tdep *tdep;
+ struct gdbarch *gdbarch;
+ struct gdbarch_list *best_arch;
+ enum arm_abi_kind arm_abi = arm_abi_global;
+ enum arm_float_model fp_model = arm_fp_model;
+ struct tdesc_arch_data *tdesc_data = NULL;
+ int i, is_m = 0;
+ int have_vfp_registers = 0, have_vfp_pseudos = 0, have_neon_pseudos = 0;
+ int have_neon = 0;
+ int have_fpa_registers = 1;
+ const struct target_desc *tdesc = info.target_desc;
+
+ /* If we have an object to base this architecture on, try to determine
+ its ABI. */
+
+ if (arm_abi == ARM_ABI_AUTO && info.abfd != NULL)
+ {
+ int ei_osabi, e_flags;
+
+ switch (bfd_get_flavour (info.abfd))
+ {
+ case bfd_target_aout_flavour:
+ /* Assume it's an old APCS-style ABI. */
+ arm_abi = ARM_ABI_APCS;
+ break;
+
+ case bfd_target_coff_flavour:
+ /* Assume it's an old APCS-style ABI. */
+ /* XXX WinCE? */
+ arm_abi = ARM_ABI_APCS;
+ break;
+
+ case bfd_target_elf_flavour:
+ ei_osabi = elf_elfheader (info.abfd)->e_ident[EI_OSABI];
+ e_flags = elf_elfheader (info.abfd)->e_flags;
+
+ if (ei_osabi == ELFOSABI_ARM)
+ {
+ /* GNU tools used to use this value, but do not for EABI
+ objects. There's nowhere to tag an EABI version
+ anyway, so assume APCS. */
+ arm_abi = ARM_ABI_APCS;
+ }
+ else if (ei_osabi == ELFOSABI_NONE)
+ {
+ int eabi_ver = EF_ARM_EABI_VERSION (e_flags);
+ int attr_arch, attr_profile;
+
+ switch (eabi_ver)
+ {
+ case EF_ARM_EABI_UNKNOWN:
+ /* Assume GNU tools. */
+ arm_abi = ARM_ABI_APCS;
+ break;
+
+ case EF_ARM_EABI_VER4:
+ case EF_ARM_EABI_VER5:
+ arm_abi = ARM_ABI_AAPCS;
+ /* EABI binaries default to VFP float ordering.
+ They may also contain build attributes that can
+ be used to identify if the VFP argument-passing
+ ABI is in use. */
+ if (fp_model == ARM_FLOAT_AUTO)
+ {
+#ifdef HAVE_ELF
+ switch (bfd_elf_get_obj_attr_int (info.abfd,
+ OBJ_ATTR_PROC,
+ Tag_ABI_VFP_args))
+ {
+ case 0:
+ /* "The user intended FP parameter/result
+ passing to conform to AAPCS, base
+ variant". */
+ fp_model = ARM_FLOAT_SOFT_VFP;
+ break;
+ case 1:
+ /* "The user intended FP parameter/result
+ passing to conform to AAPCS, VFP
+ variant". */
+ fp_model = ARM_FLOAT_VFP;
+ break;
+ case 2:
+ /* "The user intended FP parameter/result
+ passing to conform to tool chain-specific
+ conventions" - we don't know any such
+ conventions, so leave it as "auto". */
+ break;
+ default:
+ /* Attribute value not mentioned in the
+ October 2008 ABI, so leave it as
+ "auto". */
+ break;
+ }
+#else
+ fp_model = ARM_FLOAT_SOFT_VFP;
+#endif
+ }
+ break;
+
+ default:
+ /* Leave it as "auto". */
+ warning (_("unknown ARM EABI version 0x%x"), eabi_ver);
+ break;
+ }
-static void
-arm_pseudo_write (struct gdbarch *gdbarch, struct regcache *regcache,
- int regnum, const gdb_byte *buf)
-{
- const int num_regs = gdbarch_num_regs (gdbarch);
- char name_buf[4];
- gdb_byte reg_buf[8];
- int offset, double_regnum;
+#ifdef HAVE_ELF
+ /* Detect M-profile programs. This only works if the
+ executable file includes build attributes; GCC does
+ copy them to the executable, but e.g. RealView does
+ not. */
+ attr_arch = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC,
+ Tag_CPU_arch);
+ attr_profile = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC,
+ Tag_CPU_arch_profile);
+ /* GCC specifies the profile for v6-M; RealView only
+ specifies the profile for architectures starting with
+ V7 (as opposed to architectures with a tag
+ numerically greater than TAG_CPU_ARCH_V7). */
+ if (!tdesc_has_registers (tdesc)
+ && (attr_arch == TAG_CPU_ARCH_V6_M
+ || attr_arch == TAG_CPU_ARCH_V6S_M
+ || attr_profile == 'M'))
+ tdesc = tdesc_arm_with_m;
+#endif
+ }
- gdb_assert (regnum >= num_regs);
- regnum -= num_regs;
+ if (fp_model == ARM_FLOAT_AUTO)
+ {
+ int e_flags = elf_elfheader (info.abfd)->e_flags;
- if (gdbarch_tdep (gdbarch)->have_neon_pseudos && regnum >= 32 && regnum < 48)
- /* Quad-precision register. */
- arm_neon_quad_write (gdbarch, regcache, regnum - 32, buf);
- else
- {
- /* Single-precision register. */
- gdb_assert (regnum < 32);
+ switch (e_flags & (EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT))
+ {
+ case 0:
+ /* Leave it as "auto". Strictly speaking this case
+ means FPA, but almost nobody uses that now, and
+ many toolchains fail to set the appropriate bits
+ for the floating-point model they use. */
+ break;
+ case EF_ARM_SOFT_FLOAT:
+ fp_model = ARM_FLOAT_SOFT_FPA;
+ break;
+ case EF_ARM_VFP_FLOAT:
+ fp_model = ARM_FLOAT_VFP;
+ break;
+ case EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT:
+ fp_model = ARM_FLOAT_SOFT_VFP;
+ break;
+ }
+ }
- /* s0 is always the least significant half of d0. */
- if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
- offset = (regnum & 1) ? 0 : 4;
- else
- offset = (regnum & 1) ? 4 : 0;
+ if (e_flags & EF_ARM_BE8)
+ info.byte_order_for_code = BFD_ENDIAN_LITTLE;
- sprintf (name_buf, "d%d", regnum >> 1);
- double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf,
- strlen (name_buf));
+ break;
- regcache_raw_read (regcache, double_regnum, reg_buf);
- memcpy (reg_buf + offset, buf, 4);
- regcache_raw_write (regcache, double_regnum, reg_buf);
+ default:
+ /* Leave it as "auto". */
+ break;
+ }
}
-}
-
-static struct value *
-value_of_arm_user_reg (struct frame_info *frame, const void *baton)
-{
- const int *reg_p = baton;
- return value_of_register (*reg_p, frame);
-}
-\f
-static enum gdb_osabi
-arm_elf_osabi_sniffer (bfd *abfd)
-{
- unsigned int elfosabi;
- enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
-
- elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
-
- if (elfosabi == ELFOSABI_ARM)
- /* GNU tools use this value. Check note sections in this case,
- as well. */
- bfd_map_over_sections (abfd,
- generic_elf_osabi_sniff_abi_tag_sections,
- &osabi);
-
- /* Anything else will be handled by the generic ELF sniffer. */
- return osabi;
-}
-
-\f
-/* Initialize the current architecture based on INFO. If possible,
- re-use an architecture from ARCHES, which is a list of
- architectures already created during this debugging session.
-
- Called e.g. at program startup, when reading a core file, and when
- reading a binary file. */
-
-static struct gdbarch *
-arm_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
-{
- struct gdbarch_tdep *tdep;
- struct gdbarch *gdbarch;
- struct gdbarch_list *best_arch;
- enum arm_abi_kind arm_abi = arm_abi_global;
- enum arm_float_model fp_model = arm_fp_model;
- struct tdesc_arch_data *tdesc_data = NULL;
- int i;
- int have_vfp_registers = 0, have_vfp_pseudos = 0, have_neon_pseudos = 0;
- int have_neon = 0;
- int have_fpa_registers = 1;
/* Check any target description for validity. */
- if (tdesc_has_registers (info.target_desc))
+ if (tdesc_has_registers (tdesc))
{
/* For most registers we require GDB's default names; but also allow
the numeric names for sp / lr / pc, as a convenience. */
const struct tdesc_feature *feature;
int valid_p;
- feature = tdesc_find_feature (info.target_desc,
+ feature = tdesc_find_feature (tdesc,
"org.gnu.gdb.arm.core");
if (feature == NULL)
- return NULL;
+ {
+ feature = tdesc_find_feature (tdesc,
+ "org.gnu.gdb.arm.m-profile");
+ if (feature == NULL)
+ return NULL;
+ else
+ is_m = 1;
+ }
tdesc_data = tdesc_data_alloc ();
valid_p &= tdesc_numbered_register_choices (feature, tdesc_data,
ARM_PC_REGNUM,
arm_pc_names);
- valid_p &= tdesc_numbered_register (feature, tdesc_data,
- ARM_PS_REGNUM, "cpsr");
+ if (is_m)
+ valid_p &= tdesc_numbered_register (feature, tdesc_data,
+ ARM_PS_REGNUM, "xpsr");
+ else
+ valid_p &= tdesc_numbered_register (feature, tdesc_data,
+ ARM_PS_REGNUM, "cpsr");
if (!valid_p)
{
return NULL;
}
- feature = tdesc_find_feature (info.target_desc,
+ feature = tdesc_find_feature (tdesc,
"org.gnu.gdb.arm.fpa");
if (feature != NULL)
{
else
have_fpa_registers = 0;
- feature = tdesc_find_feature (info.target_desc,
+ feature = tdesc_find_feature (tdesc,
"org.gnu.gdb.xscale.iwmmxt");
if (feature != NULL)
{
/* If we have a VFP unit, check whether the single precision registers
are present. If not, then we will synthesize them as pseudo
registers. */
- feature = tdesc_find_feature (info.target_desc,
+ feature = tdesc_find_feature (tdesc,
"org.gnu.gdb.arm.vfp");
if (feature != NULL)
{
/* If we have VFP, also check for NEON. The architecture allows
NEON without VFP (integer vector operations only), but GDB
does not support that. */
- feature = tdesc_find_feature (info.target_desc,
+ feature = tdesc_find_feature (tdesc,
"org.gnu.gdb.arm.neon");
if (feature != NULL)
{
}
}
- /* If we have an object to base this architecture on, try to determine
- its ABI. */
-
- if (arm_abi == ARM_ABI_AUTO && info.abfd != NULL)
- {
- int ei_osabi, e_flags;
-
- switch (bfd_get_flavour (info.abfd))
- {
- case bfd_target_aout_flavour:
- /* Assume it's an old APCS-style ABI. */
- arm_abi = ARM_ABI_APCS;
- break;
-
- case bfd_target_coff_flavour:
- /* Assume it's an old APCS-style ABI. */
- /* XXX WinCE? */
- arm_abi = ARM_ABI_APCS;
- break;
-
- case bfd_target_elf_flavour:
- ei_osabi = elf_elfheader (info.abfd)->e_ident[EI_OSABI];
- e_flags = elf_elfheader (info.abfd)->e_flags;
-
- if (ei_osabi == ELFOSABI_ARM)
- {
- /* GNU tools used to use this value, but do not for EABI
- objects. There's nowhere to tag an EABI version
- anyway, so assume APCS. */
- arm_abi = ARM_ABI_APCS;
- }
- else if (ei_osabi == ELFOSABI_NONE)
- {
- int eabi_ver = EF_ARM_EABI_VERSION (e_flags);
-
- switch (eabi_ver)
- {
- case EF_ARM_EABI_UNKNOWN:
- /* Assume GNU tools. */
- arm_abi = ARM_ABI_APCS;
- break;
-
- case EF_ARM_EABI_VER4:
- case EF_ARM_EABI_VER5:
- arm_abi = ARM_ABI_AAPCS;
- /* EABI binaries default to VFP float ordering.
- They may also contain build attributes that can
- be used to identify if the VFP argument-passing
- ABI is in use. */
- if (fp_model == ARM_FLOAT_AUTO)
- {
-#ifdef HAVE_ELF
- switch (bfd_elf_get_obj_attr_int (info.abfd,
- OBJ_ATTR_PROC,
- Tag_ABI_VFP_args))
- {
- case 0:
- /* "The user intended FP parameter/result
- passing to conform to AAPCS, base
- variant". */
- fp_model = ARM_FLOAT_SOFT_VFP;
- break;
- case 1:
- /* "The user intended FP parameter/result
- passing to conform to AAPCS, VFP
- variant". */
- fp_model = ARM_FLOAT_VFP;
- break;
- case 2:
- /* "The user intended FP parameter/result
- passing to conform to tool chain-specific
- conventions" - we don't know any such
- conventions, so leave it as "auto". */
- break;
- default:
- /* Attribute value not mentioned in the
- October 2008 ABI, so leave it as
- "auto". */
- break;
- }
-#else
- fp_model = ARM_FLOAT_SOFT_VFP;
-#endif
- }
- break;
-
- default:
- /* Leave it as "auto". */
- warning (_("unknown ARM EABI version 0x%x"), eabi_ver);
- break;
- }
- }
-
- if (fp_model == ARM_FLOAT_AUTO)
- {
- int e_flags = elf_elfheader (info.abfd)->e_flags;
-
- switch (e_flags & (EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT))
- {
- case 0:
- /* Leave it as "auto". Strictly speaking this case
- means FPA, but almost nobody uses that now, and
- many toolchains fail to set the appropriate bits
- for the floating-point model they use. */
- break;
- case EF_ARM_SOFT_FLOAT:
- fp_model = ARM_FLOAT_SOFT_FPA;
- break;
- case EF_ARM_VFP_FLOAT:
- fp_model = ARM_FLOAT_VFP;
- break;
- case EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT:
- fp_model = ARM_FLOAT_SOFT_VFP;
- break;
- }
- }
-
- if (e_flags & EF_ARM_BE8)
- info.byte_order_for_code = BFD_ENDIAN_LITTLE;
-
- break;
-
- default:
- /* Leave it as "auto". */
- break;
- }
- }
-
/* If there is already a candidate, use it. */
for (best_arch = gdbarch_list_lookup_by_info (arches, &info);
best_arch != NULL;
since gdbarches with a different target description are
automatically disqualified. */
+ /* Do check is_m, though, since it might come from the binary. */
+ if (is_m != gdbarch_tdep (best_arch->gdbarch)->is_m)
+ continue;
+
/* Found a match. */
break;
}
These are gdbarch discriminators, like the OSABI. */
tdep->arm_abi = arm_abi;
tdep->fp_model = fp_model;
+ tdep->is_m = is_m;
tdep->have_fpa_registers = have_fpa_registers;
tdep->have_vfp_registers = have_vfp_registers;
tdep->have_vfp_pseudos = have_vfp_pseudos;
/* On ARM targets char defaults to unsigned. */
set_gdbarch_char_signed (gdbarch, 0);
+ /* Note: for displaced stepping, this includes the breakpoint, and one word
+ of additional scratch space. This setting isn't used for anything beside
+ displaced stepping at present. */
+ set_gdbarch_max_insn_length (gdbarch, 4 * DISPLACED_MODIFIED_INSNS);
+
/* This should be low enough for everything. */
tdep->lowest_pc = 0x20;
tdep->jb_pc = -1; /* Longjump support not enabled by default. */
/* Advance PC across function entry code. */
set_gdbarch_skip_prologue (gdbarch, arm_skip_prologue);
+ /* Detect whether PC is in function epilogue. */
+ set_gdbarch_in_function_epilogue_p (gdbarch, arm_in_function_epilogue_p);
+
/* Skip trampolines. */
set_gdbarch_skip_trampoline_code (gdbarch, arm_skip_stub);
/* Breakpoint manipulation. */
set_gdbarch_breakpoint_from_pc (gdbarch, arm_breakpoint_from_pc);
+ set_gdbarch_remote_breakpoint_from_pc (gdbarch,
+ arm_remote_breakpoint_from_pc);
/* Information about registers, etc. */
set_gdbarch_deprecated_fp_regnum (gdbarch, ARM_FP_REGNUM); /* ??? */
arm_coff_make_msymbol_special);
set_gdbarch_record_special_symbol (gdbarch, arm_record_special_symbol);
+ /* Thumb-2 IT block support. */
+ set_gdbarch_adjust_breakpoint_address (gdbarch,
+ arm_adjust_breakpoint_address);
+
/* Virtual tables. */
set_gdbarch_vbit_in_delta (gdbarch, 1);
{
set_tdesc_pseudo_register_name (gdbarch, arm_register_name);
- tdesc_use_registers (gdbarch, info.target_desc, tdesc_data);
+ tdesc_use_registers (gdbarch, tdesc, tdesc_data);
/* Override tdesc_register_type to adjust the types of VFP
registers for NEON. */
gdbarch_register (bfd_arch_arm, arm_gdbarch_init, arm_dump_tdep);
arm_objfile_data_key
- = register_objfile_data_with_cleanup (arm_objfile_data_cleanup);
+ = register_objfile_data_with_cleanup (NULL, arm_objfile_data_free);
/* Register an ELF OS ABI sniffer for ARM binaries. */
gdbarch_register_osabi_sniffer (bfd_arch_arm,
bfd_target_elf_flavour,
arm_elf_osabi_sniffer);
+ /* Initialize the standard target descriptions. */
+ initialize_tdesc_arm_with_m ();
+
/* Get the number of possible sets of register names defined in opcodes. */
num_disassembly_options = get_arm_regname_num_options ();
_("The valid values are:\n"),
regdesc,
_("The default is \"std\"."));
- helptext = ui_file_xstrdup (stb, &length);
+ helptext = ui_file_xstrdup (stb, NULL);
ui_file_delete (stb);
add_setshow_enum_cmd("disassembler", no_class,
projects / deliverable / binutils-gdb.git / blobdiff