/* Target dependent code for the Motorola 68000 series.
- Copyright (C) 1990 Free Software Foundation, Inc.
+ Copyright (C) 1990, 1992 Free Software Foundation, Inc.
This file is part of GDB.
-GDB is free software; you can redistribute it and/or modify
+This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 1, or (at your option)
-any later version.
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
-GDB is distributed in the hope that it will be useful,
+This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
-along with GDB; see the file COPYING. If not, write to
-the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "defs.h"
-#include "ieee-float.h"
+#include "frame.h"
+#include "symtab.h"
-const struct ext_format ext_format_68881 [] = {
-/* tot sbyte smask expbyte manbyte */
- { 12, 0, 0x80, 0,1, 4,8 }, /* mc68881 */
-};
+\f
+/* Push an empty stack frame, to record the current PC, etc. */
+
+void
+m68k_push_dummy_frame ()
+{
+ register CORE_ADDR sp = read_register (SP_REGNUM);
+ register int regnum;
+ char raw_buffer[12];
+
+ sp = push_word (sp, read_register (PC_REGNUM));
+ sp = push_word (sp, read_register (FP_REGNUM));
+ write_register (FP_REGNUM, sp);
+#if defined (HAVE_68881)
+ for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--)
+ {
+ read_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12);
+ sp = push_bytes (sp, raw_buffer, 12);
+ }
+#endif
+ for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--)
+ {
+ sp = push_word (sp, read_register (regnum));
+ }
+ sp = push_word (sp, read_register (PS_REGNUM));
+ write_register (SP_REGNUM, sp);
+}
+
+/* Discard from the stack the innermost frame,
+ restoring all saved registers. */
+
+void
+m68k_pop_frame ()
+{
+ register FRAME frame = get_current_frame ();
+ register CORE_ADDR fp;
+ register int regnum;
+ struct frame_saved_regs fsr;
+ struct frame_info *fi;
+ char raw_buffer[12];
+
+ fi = get_frame_info (frame);
+ fp = fi -> frame;
+ get_frame_saved_regs (fi, &fsr);
+#if defined (HAVE_68881)
+ for (regnum = FP0_REGNUM + 7 ; regnum >= FP0_REGNUM ; regnum--)
+ {
+ if (fsr.regs[regnum])
+ {
+ read_memory (fsr.regs[regnum], raw_buffer, 12);
+ write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12);
+ }
+ }
+#endif
+ for (regnum = FP_REGNUM - 1 ; regnum >= 0 ; regnum--)
+ {
+ if (fsr.regs[regnum])
+ {
+ write_register (regnum, read_memory_integer (fsr.regs[regnum], 4));
+ }
+ }
+ if (fsr.regs[PS_REGNUM])
+ {
+ write_register (PS_REGNUM, read_memory_integer (fsr.regs[PS_REGNUM], 4));
+ }
+ write_register (FP_REGNUM, read_memory_integer (fp, 4));
+ write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));
+ write_register (SP_REGNUM, fp + 8);
+ flush_cached_frames ();
+ set_current_frame (create_new_frame (read_register (FP_REGNUM),
+ read_pc ()));
+}
+
+\f
+/* Given an ip value corresponding to the start of a function,
+ return the ip of the first instruction after the function
+ prologue. This is the generic m68k support. Machines which
+ require something different can override the SKIP_PROLOGUE
+ macro to point elsewhere.
+
+ Some instructions which typically may appear in a function
+ prologue include:
+
+ A link instruction, word form:
+
+ link.w %a6,&0 4e56 XXXX
+
+ A link instruction, long form:
+
+ link.l %fp,&F%1 480e XXXX XXXX
+
+ A movm instruction to preserve integer regs:
+
+ movm.l &M%1,(4,%sp) 48ef XXXX XXXX
+
+ A fmovm instruction to preserve float regs:
+
+ fmovm &FPM%1,(FPO%1,%sp) f237 XXXX XXXX XXXX XXXX
+
+ Some profiling setup code (FIXME, not recognized yet):
+
+ lea.l (.L3,%pc),%a1 43fb XXXX XXXX XXXX
+ bsr _mcount 61ff XXXX XXXX
+
+ */
+
+#define P_LINK_L 0x480e
+#define P_LINK_W 0x4e56
+#define P_MOV_L 0x207c
+#define P_JSR 0x4eb9
+#define P_BSR 0x61ff
+#define P_LEA_L 0x43fb
+#define P_MOVM_L 0x48ef
+#define P_FMOVM 0xf237
+#define P_TRAP 0x4e40
+
+CORE_ADDR
+m68k_skip_prologue (ip)
+CORE_ADDR ip;
+{
+ register CORE_ADDR limit;
+ struct symtab_and_line sal;
+ register int op;
+
+ /* Find out if there is a known limit for the extent of the prologue.
+ If so, ensure we don't go past it. If not, assume "infinity". */
+
+ sal = find_pc_line (ip, 0);
+ limit = (sal.end) ? sal.end : (CORE_ADDR) ~0;
+
+ while (ip < limit)
+ {
+ op = read_memory_integer (ip, 2);
+ op &= 0xFFFF;
+
+ if (op == P_LINK_W)
+ {
+ ip += 4; /* Skip link.w */
+ }
+ else if (op == P_LINK_L)
+ {
+ ip += 6; /* Skip link.l */
+ }
+ else if (op == P_MOVM_L)
+ {
+ ip += 6; /* Skip movm.l */
+ }
+ else if (op == P_FMOVM)
+ {
+ ip += 10; /* Skip fmovm */
+ }
+ else
+ {
+ break; /* Found unknown code, bail out. */
+ }
+ }
+ return (ip);
+}
+
+void
+m68k_find_saved_regs (frame_info, saved_regs)
+ struct frame_info *frame_info;
+ struct frame_saved_regs *saved_regs;
+{
+ register int regnum;
+ register int regmask;
+ register CORE_ADDR next_addr;
+ register CORE_ADDR pc;
+
+ /* First possible address for a pc in a call dummy for this frame. */
+ CORE_ADDR possible_call_dummy_start =
+ (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM*4 - 4
+#if defined (HAVE_68881)
+ - 8*12
+#endif
+ ;
+
+ int nextinsn;
+ memset (saved_regs, 0, sizeof (*saved_regs));
+ if ((frame_info)->pc >= possible_call_dummy_start
+ && (frame_info)->pc <= (frame_info)->frame)
+ {
+
+ /* It is a call dummy. We could just stop now, since we know
+ what the call dummy saves and where. But this code proceeds
+ to parse the "prologue" which is part of the call dummy.
+ This is needlessly complex, confusing, and also is the only
+ reason that the call dummy is customized based on HAVE_68881.
+ FIXME. */
+
+ next_addr = (frame_info)->frame;
+ pc = possible_call_dummy_start;
+ }
+ else
+ {
+ pc = get_pc_function_start ((frame_info)->pc);
+ /* Verify we have a link a6 instruction next;
+ if not we lose. If we win, find the address above the saved
+ regs using the amount of storage from the link instruction. */
+ if (044016 == read_memory_integer (pc, 2))
+ next_addr = (frame_info)->frame + read_memory_integer (pc += 2, 4), pc+=4;
+ else if (047126 == read_memory_integer (pc, 2))
+ next_addr = (frame_info)->frame + read_memory_integer (pc += 2, 2), pc+=2;
+ else goto lose;
+ /* If have an addal #-n, sp next, adjust next_addr. */
+ if ((0177777 & read_memory_integer (pc, 2)) == 0157774)
+ next_addr += read_memory_integer (pc += 2, 4), pc += 4;
+ }
+ regmask = read_memory_integer (pc + 2, 2);
+#if defined (HAVE_68881)
+ /* Here can come an fmovem. Check for it. */
+ nextinsn = 0xffff & read_memory_integer (pc, 2);
+ if (0xf227 == nextinsn
+ && (regmask & 0xff00) == 0xe000)
+ { pc += 4; /* Regmask's low bit is for register fp7, the first pushed */
+ for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--, regmask >>= 1)
+ if (regmask & 1)
+ saved_regs->regs[regnum] = (next_addr -= 12);
+ regmask = read_memory_integer (pc + 2, 2); }
+#endif
+ /* next should be a moveml to (sp) or -(sp) or a movl r,-(sp) */
+ if (0044327 == read_memory_integer (pc, 2))
+ { pc += 4; /* Regmask's low bit is for register 0, the first written */
+ for (regnum = 0; regnum < 16; regnum++, regmask >>= 1)
+ if (regmask & 1)
+ saved_regs->regs[regnum] = (next_addr += 4) - 4; }
+ else if (0044347 == read_memory_integer (pc, 2))
+ {
+ pc += 4; /* Regmask's low bit is for register 15, the first pushed */
+ for (regnum = 15; regnum >= 0; regnum--, regmask >>= 1)
+ if (regmask & 1)
+ saved_regs->regs[regnum] = (next_addr -= 4);
+ }
+ else if (0x2f00 == (0xfff0 & read_memory_integer (pc, 2)))
+ {
+ regnum = 0xf & read_memory_integer (pc, 2); pc += 2;
+ saved_regs->regs[regnum] = (next_addr -= 4);
+ /* gcc, at least, may use a pair of movel instructions when saving
+ exactly 2 registers. */
+ if (0x2f00 == (0xfff0 & read_memory_integer (pc, 2)))
+ {
+ regnum = 0xf & read_memory_integer (pc, 2);
+ pc += 2;
+ saved_regs->regs[regnum] = (next_addr -= 4);
+ }
+ }
+#if defined (HAVE_68881)
+ /* fmovemx to index of sp may follow. */
+ regmask = read_memory_integer (pc + 2, 2);
+ nextinsn = 0xffff & read_memory_integer (pc, 2);
+ if (0xf236 == nextinsn
+ && (regmask & 0xff00) == 0xf000)
+ { pc += 10; /* Regmask's low bit is for register fp0, the first written */
+ for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--, regmask >>= 1)
+ if (regmask & 1)
+ saved_regs->regs[regnum] = (next_addr += 12) - 12;
+ regmask = read_memory_integer (pc + 2, 2); }
+#endif
+ /* clrw -(sp); movw ccr,-(sp) may follow. */
+ if (0x426742e7 == read_memory_integer (pc, 4))
+ saved_regs->regs[PS_REGNUM] = (next_addr -= 4);
+ lose: ;
+ saved_regs->regs[SP_REGNUM] = (frame_info)->frame + 8;
+ saved_regs->regs[FP_REGNUM] = (frame_info)->frame;
+ saved_regs->regs[PC_REGNUM] = (frame_info)->frame + 4;
+#ifdef SIG_SP_FP_OFFSET
+ /* Adjust saved SP_REGNUM for fake _sigtramp frames. */
+ if (frame_info->signal_handler_caller && frame_info->next)
+ saved_regs->regs[SP_REGNUM] = frame_info->next->frame + SIG_SP_FP_OFFSET;
+#endif
+}
+
+
+#ifdef USE_PROC_FS /* Target dependent support for /proc */
+
+#include <sys/procfs.h>
+
+/* The /proc interface divides the target machine's register set up into
+ two different sets, the general register set (gregset) and the floating
+ point register set (fpregset). For each set, there is an ioctl to get
+ the current register set and another ioctl to set the current values.
+
+ The actual structure passed through the ioctl interface is, of course,
+ naturally machine dependent, and is different for each set of registers.
+ For the m68k for example, the general register set is typically defined
+ by:
+
+ typedef int gregset_t[18];
+
+ #define R_D0 0
+ ...
+ #define R_PS 17
+
+ and the floating point set by:
+
+ typedef struct fpregset {
+ int f_pcr;
+ int f_psr;
+ int f_fpiaddr;
+ int f_fpregs[8][3]; (8 regs, 96 bits each)
+ } fpregset_t;
+
+ These routines provide the packing and unpacking of gregset_t and
+ fpregset_t formatted data.
+
+ */
+
+
+/* Given a pointer to a general register set in /proc format (gregset_t *),
+ unpack the register contents and supply them as gdb's idea of the current
+ register values. */
+
+void
+supply_gregset (gregsetp)
+gregset_t *gregsetp;
+{
+ register int regi;
+ register greg_t *regp = (greg_t *) gregsetp;
+
+ for (regi = 0 ; regi < R_PC ; regi++)
+ {
+ supply_register (regi, (char *) (regp + regi));
+ }
+ supply_register (PS_REGNUM, (char *) (regp + R_PS));
+ supply_register (PC_REGNUM, (char *) (regp + R_PC));
+}
+
+void
+fill_gregset (gregsetp, regno)
+gregset_t *gregsetp;
+int regno;
+{
+ register int regi;
+ register greg_t *regp = (greg_t *) gregsetp;
+ extern char registers[];
+
+ for (regi = 0 ; regi < R_PC ; regi++)
+ {
+ if ((regno == -1) || (regno == regi))
+ {
+ *(regp + regi) = *(int *) ®isters[REGISTER_BYTE (regi)];
+ }
+ }
+ if ((regno == -1) || (regno == PS_REGNUM))
+ {
+ *(regp + R_PS) = *(int *) ®isters[REGISTER_BYTE (PS_REGNUM)];
+ }
+ if ((regno == -1) || (regno == PC_REGNUM))
+ {
+ *(regp + R_PC) = *(int *) ®isters[REGISTER_BYTE (PC_REGNUM)];
+ }
+}
+
+#if defined (FP0_REGNUM)
+
+/* Given a pointer to a floating point register set in /proc format
+ (fpregset_t *), unpack the register contents and supply them as gdb's
+ idea of the current floating point register values. */
+
+void
+supply_fpregset (fpregsetp)
+fpregset_t *fpregsetp;
+{
+ register int regi;
+ char *from;
+
+ for (regi = FP0_REGNUM ; regi < FPC_REGNUM ; regi++)
+ {
+ from = (char *) &(fpregsetp -> f_fpregs[regi-FP0_REGNUM][0]);
+ supply_register (regi, from);
+ }
+ supply_register (FPC_REGNUM, (char *) &(fpregsetp -> f_pcr));
+ supply_register (FPS_REGNUM, (char *) &(fpregsetp -> f_psr));
+ supply_register (FPI_REGNUM, (char *) &(fpregsetp -> f_fpiaddr));
+}
+
+/* Given a pointer to a floating point register set in /proc format
+ (fpregset_t *), update the register specified by REGNO from gdb's idea
+ of the current floating point register set. If REGNO is -1, update
+ them all. */
+
+void
+fill_fpregset (fpregsetp, regno)
+fpregset_t *fpregsetp;
+int regno;
+{
+ int regi;
+ char *to;
+ char *from;
+ extern char registers[];
+
+ for (regi = FP0_REGNUM ; regi < FPC_REGNUM ; regi++)
+ {
+ if ((regno == -1) || (regno == regi))
+ {
+ from = (char *) ®isters[REGISTER_BYTE (regi)];
+ to = (char *) &(fpregsetp -> f_fpregs[regi-FP0_REGNUM][0]);
+ memcpy (to, from, REGISTER_RAW_SIZE (regi));
+ }
+ }
+ if ((regno == -1) || (regno == FPC_REGNUM))
+ {
+ fpregsetp -> f_pcr = *(int *) ®isters[REGISTER_BYTE (FPC_REGNUM)];
+ }
+ if ((regno == -1) || (regno == FPS_REGNUM))
+ {
+ fpregsetp -> f_psr = *(int *) ®isters[REGISTER_BYTE (FPS_REGNUM)];
+ }
+ if ((regno == -1) || (regno == FPI_REGNUM))
+ {
+ fpregsetp -> f_fpiaddr = *(int *) ®isters[REGISTER_BYTE (FPI_REGNUM)];
+ }
+}
+
+#endif /* defined (FP0_REGNUM) */
+
+#endif /* USE_PROC_FS */
+
+#ifdef GET_LONGJMP_TARGET
+/* Figure out where the longjmp will land. Slurp the args out of the stack.
+ We expect the first arg to be a pointer to the jmp_buf structure from which
+ we extract the pc (JB_PC) that we will land at. The pc is copied into PC.
+ This routine returns true on success. */
+
+int
+get_longjmp_target(pc)
+ CORE_ADDR *pc;
+{
+ char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
+ CORE_ADDR sp, jb_addr;
+
+ sp = read_register(SP_REGNUM);
+
+ if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */
+ buf,
+ TARGET_PTR_BIT / TARGET_CHAR_BIT))
+ return 0;
+
+ jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
+
+ if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
+ TARGET_PTR_BIT / TARGET_CHAR_BIT))
+ return 0;
+
+ *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
+
+ return 1;
+}
+#endif /* GET_LONGJMP_TARGET */
+
+/* Immediately after a function call, return the saved pc before the frame
+ is setup. For sun3's, we check for the common case of being inside of a
+ system call, and if so, we know that Sun pushes the call # on the stack
+ prior to doing the trap. */
+
+CORE_ADDR
+m68k_saved_pc_after_call(frame)
+ struct frame_info *frame;
+{
+#ifdef GDB_TARGET_IS_SUN3
+ int op;
+
+ op = read_memory_integer (frame->pc, 2);
+ op &= 0xFFFF;
+
+ if (op == P_TRAP)
+ return read_memory_integer (read_register (SP_REGNUM) + 4, 4);
+ else
+#endif /* GDB_TARGET_IS_SUN3 */
+ return read_memory_integer (read_register (SP_REGNUM), 4);
+}
projects / deliverable / binutils-gdb.git / blobdiff