gdb: microblaze: delete useless stubs

[deliverable/binutils-gdb.git] / gdb / nios2-linux-tdep.c

diff --git a/gdb/nios2-linux-tdep.c b/gdb/nios2-linux-tdep.c
index b9ee922038132f8c50b2d8ec54966ca9ba96dde1..0a837b0a0931bdd644d083eb4fcce5855ea65839 100644 (file)
--- a/gdb/nios2-linux-tdep.c
+++ b/gdb/nios2-linux-tdep.c
@@ -1,5 +1,5 @@
 /* Target-dependent code for GNU/Linux on Nios II.
-   Copyright (C) 2012-2014 Free Software Foundation, Inc.
+   Copyright (C) 2012-2015 Free Software Foundation, Inc.
    Contributed by Mentor Graphics, Inc.
 
    This file is part of GDB.
@@ -49,6 +49,11 @@ static const int reg_offsets[NIOS2_NUM_REGS] =
   -1, -1, -1, -1, -1, -1, -1, -1
 };
 
+/* General register set size.  Should match sizeof (struct pt_regs) +
+   sizeof (struct switch_stack) from the NIOS2 Linux kernel patch.  */
+
+#define NIOS2_GREGS_SIZE (4 * 34)
+
 /* Implement the supply_regset hook for core files.  */
 
 static void
@@ -97,20 +102,37 @@ static const struct regset nios2_core_regset =
   nios2_collect_gregset
 };
 
-/* Implement the regset_from_core_section gdbarch method.  */
+/* Iterate over core file register note sections.  */
 
-static const struct regset *
-nios2_regset_from_core_section (struct gdbarch *gdbarch,
-                                const char *sect_name, size_t sect_size)
+static void
+nios2_iterate_over_regset_sections (struct gdbarch *gdbarch,
+                                   iterate_over_regset_sections_cb *cb,
+                                   void *cb_data,
+                                   const struct regcache *regcache)
 {
-  if (strcmp (sect_name, ".reg") == 0)
-    return &nios2_core_regset;
-
-  return NULL;
+  cb (".reg", NIOS2_GREGS_SIZE, &nios2_core_regset, NULL, cb_data);
 }
 
 /* Initialize a trad-frame cache corresponding to the tramp-frame.
-   FUNC is the address of the instruction TRAMP[0] in memory.  */
+   FUNC is the address of the instruction TRAMP[0] in memory.
+
+   This ABI is not documented.  It corresponds to rt_setup_ucontext in
+   the kernel arch/nios2/kernel/signal.c file.
+
+   The key points are:
+   - The kernel creates a trampoline at the hard-wired address 0x1044.
+   - The stack pointer points to an object of type struct rt_sigframe.
+     The definition of this structure is not exported from the kernel.
+     The register save area is located at offset 152 bytes (as determined
+     by inspection of the stack contents in the debugger), and the
+     registers are saved as r1-r23, ra, fp, gp, ea, sp.
+
+   This interface was implemented with kernel version 3.19 (the first
+   official mainline kernel).  Older unofficial kernel versions used
+   incompatible conventions; we do not support those here.  */
+
+#define NIOS2_SIGRETURN_TRAMP_ADDR 0x1044
+#define NIOS2_SIGRETURN_REGSAVE_OFFSET 152
 
 static void
 nios2_linux_rt_sigreturn_init (const struct tramp_frame *self,
@@ -118,7 +140,8 @@ nios2_linux_rt_sigreturn_init (const struct tramp_frame *self,
                               struct trad_frame_cache *this_cache,
                               CORE_ADDR func)
 {
-  CORE_ADDR base = func + 41 * 4;
+  CORE_ADDR sp = get_frame_register_unsigned (next_frame, NIOS2_SP_REGNUM);
+  CORE_ADDR base = sp + NIOS2_SIGRETURN_REGSAVE_OFFSET;
   int i;
 
   for (i = 0; i < 23; i++)
@@ -181,8 +204,8 @@ nios2_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
                                              svr4_fetch_objfile_link_map);
   /* Core file support.  */
-  set_gdbarch_regset_from_core_section (gdbarch,
-                                        nios2_regset_from_core_section);
+  set_gdbarch_iterate_over_regset_sections
+    (gdbarch, nios2_iterate_over_regset_sections);
   /* Linux signal frame unwinders.  */
   tramp_frame_prepend_unwinder (gdbarch,
                                 &nios2_linux_rt_sigreturn_tramp_frame);