Modernize NetBSD/powerpc support in GDB

[Mark Kettenis <mark dot kettenis at xs4all dot nl>]

Hi Nathan,

Here's an updated version of a patch that I sent you many months ago.
I'd like to get it out of my tree, so please review.  The patch makes
the powerpc-*-netbsd* target catch up with most of the other *BSD
targets, and makes the number of testsuite failures on NetBSD/macppc
3.0 go down from around 800 to around 700.  So if I don't hear from
you, I inted to check this in in two weeks or so ;-).  I beleive I got
similar results on a NetBSD/macppc 2.0-ish system in the past.

The number of testsuite failures is quite high for a powerpc-*-*
target; on OpenBSD/macppc I get slightly over 230 failures.  It seems
that NetBSD is randomly skipping breakpoints, which is the tell-tale
sign of cache flushing issues.  I had similar problems on several
OpenBSD targets until flushing the instruction cache was implemented
properly for memory writes through ptrace(2).  Recently Dale Rahn told
me that the NetBSD/powerpc instruction cache flushing routines in pmap
didn't seem to work for him.  Hope you can forward this info to a
NetBSD developer who can fix things.

Mark

Index: ppcnbsd-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/ppcnbsd-nat.c,v
retrieving revision 1.20
diff -u -p -r1.20 ppcnbsd-nat.c
--- ppcnbsd-nat.c	17 Dec 2005 22:34:01 -0000	1.20
+++ ppcnbsd-nat.c	2 May 2006 19:29:26 -0000
@@ -1,5 +1,7 @@
-/* Native-dependent code for PowerPC's running NetBSD, for GDB.
-   Copyright (C) 2002, 2004 Free Software Foundation, Inc.
+/* Native-dependent code for NetBSD/powerpc.
+
+   Copyright (C) 2002, 2004, 2005, 2006 Free Software Foundation, Inc.
+
    Contributed by Wasabi Systems, Inc.
 
    This file is part of GDB.
@@ -26,35 +28,37 @@
 #include <machine/pcb.h>
 
 #include "defs.h"
-#include "inferior.h"
-#include "gdb_assert.h"
 #include "gdbcore.h"
+#include "inferior.h"
 #include "regcache.h"
-#include "bsd-kvm.h"
+
+#include "gdb_assert.h"
 
 #include "ppc-tdep.h"
 #include "ppcnbsd-tdep.h"
-
+#include "bsd-kvm.h"
 #include "inf-ptrace.h"
 
 /* Returns true if PT_GETREGS fetches this register.  */
+
 static int
-getregs_supplies (int regno)
+getregs_supplies (int regnum)
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
 
-  return ((regno >= tdep->ppc_gp0_regnum
-           && regno < tdep->ppc_gp0_regnum + ppc_num_gprs)
-          || regno == tdep->ppc_lr_regnum
-          || regno == tdep->ppc_cr_regnum
-          || regno == tdep->ppc_xer_regnum
-          || regno == tdep->ppc_ctr_regnum
-	  || regno == PC_REGNUM);
+  return ((regnum >= tdep->ppc_gp0_regnum
+           && regnum < tdep->ppc_gp0_regnum + ppc_num_gprs)
+          || regnum == tdep->ppc_lr_regnum
+          || regnum == tdep->ppc_cr_regnum
+          || regnum == tdep->ppc_xer_regnum
+          || regnum == tdep->ppc_ctr_regnum
+	  || regnum == PC_REGNUM);
 }
 
 /* Like above, but for PT_GETFPREGS.  */
+
 static int
-getfpregs_supplies (int regno)
+getfpregs_supplies (int regnum)
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
 
@@ -70,15 +74,15 @@ getfpregs_supplies (int regno)
      combination to the problem.  */
   gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
 
-  return ((regno >= tdep->ppc_fp0_regnum
-           && regno < tdep->ppc_fp0_regnum + ppc_num_fprs)
-	  || regno == tdep->ppc_fpscr_regnum);
+  return ((regnum >= tdep->ppc_fp0_regnum
+           && regnum < tdep->ppc_fp0_regnum + ppc_num_fprs)
+	  || regnum == tdep->ppc_fpscr_regnum);
 }
 
 static void
-ppcnbsd_fetch_inferior_registers (int regno)
+ppcnbsd_fetch_inferior_registers (int regnum)
 {
-  if (regno == -1 || getregs_supplies (regno))
+  if (regnum == -1 || getregs_supplies (regnum))
     {
       struct reg regs;
 
@@ -86,12 +90,11 @@ ppcnbsd_fetch_inferior_registers (int re
 		  (PTRACE_TYPE_ARG3) &regs, 0) == -1)
         perror_with_name (_("Couldn't get registers"));
 
-      ppcnbsd_supply_reg ((char *) &regs, regno);
-      if (regno != -1)
-	return;
+      ppc_supply_gregset (&ppcnbsd_gregset, current_regcache,
+			  regnum, &regs, sizeof regs);
     }
 
-  if (regno == -1 || getfpregs_supplies (regno))
+  if (regnum == -1 || getfpregs_supplies (regnum))
     {
       struct fpreg fpregs;
 
@@ -99,16 +102,15 @@ ppcnbsd_fetch_inferior_registers (int re
 		  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 	perror_with_name (_("Couldn't get FP registers"));
 
-      ppcnbsd_supply_fpreg ((char *) &fpregs, regno);
-      if (regno != -1)
-	return;
+      ppc_supply_fpregset (&ppcnbsd_fpregset, current_regcache,
+			   regnum, &fpregs, sizeof fpregs);
     }
 }
 
 static void
-ppcnbsd_store_inferior_registers (int regno)
+ppcnbsd_store_inferior_registers (int regnum)
 {
-  if (regno == -1 || getregs_supplies (regno))
+  if (regnum == -1 || getregs_supplies (regnum))
     {
       struct reg regs;
 
@@ -116,17 +118,15 @@ ppcnbsd_store_inferior_registers (int re
 		  (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 	perror_with_name (_("Couldn't get registers"));
 
-      ppcnbsd_fill_reg ((char *) &regs, regno);
+      ppc_collect_gregset (&ppcnbsd_gregset, current_regcache,
+			   regnum, &regs, sizeof regs);
 
       if (ptrace (PT_SETREGS, PIDGET (inferior_ptid),
 		  (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 	perror_with_name (_("Couldn't write registers"));
-
-      if (regno != -1)
-	return;
     }
 
-  if (regno == -1 || getfpregs_supplies (regno))
+  if (regnum == -1 || getfpregs_supplies (regnum))
     {
       struct fpreg fpregs;
 
@@ -134,8 +134,9 @@ ppcnbsd_store_inferior_registers (int re
 		  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 	perror_with_name (_("Couldn't get FP registers"));
 
-      ppcnbsd_fill_fpreg ((char *) &fpregs, regno);
-      
+      ppc_collect_fpregset (&ppcnbsd_fpregset, current_regcache,
+			    regnum, &fpregs, sizeof fpregs);
+
       if (ptrace (PT_SETFPREGS, PIDGET (inferior_ptid),
 		  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 	perror_with_name (_("Couldn't set FP registers"));
@@ -154,19 +155,19 @@ ppcnbsd_supply_pcb (struct regcache *reg
   if (pcb->pcb_sp == 0)
     return 0;
 
-  read_memory (pcb->pcb_sp, (char *) &sf, sizeof sf);
+  read_memory (pcb->pcb_sp, (gdb_byte *)&sf, sizeof sf);
   regcache_raw_supply (regcache, tdep->ppc_cr_regnum, &sf.cr);
   regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 2, &sf.fixreg2);
   for (i = 0 ; i < 19 ; i++)
     regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 13 + i,
 			 &sf.fixreg[i]);
 
-  read_memory(sf.sp, (char *)&cf, sizeof(cf));
+  read_memory(sf.sp, (gdb_byte *)&cf, sizeof(cf));
   regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 30, &cf.r30);
   regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 31, &cf.r31);
   regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 1, &cf.sp);
 
-  read_memory(cf.sp, (char *)&cf, sizeof(cf));
+  read_memory(cf.sp, (gdb_byte *)&cf, sizeof(cf));
   regcache_raw_supply (regcache, tdep->ppc_lr_regnum, &cf.lr);
   regcache_raw_supply (regcache, PC_REGNUM, &cf.lr);
 
@@ -180,8 +181,10 @@ void
 _initialize_ppcnbsd_nat (void)
 {
   struct target_ops *t;
+
   /* Support debugging kernel virtual memory images.  */
   bsd_kvm_add_target (ppcnbsd_supply_pcb);
+
   /* Add in local overrides.  */
   t = inf_ptrace_target ();
   t->to_fetch_registers = ppcnbsd_fetch_inferior_registers;
Index: ppcnbsd-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/ppcnbsd-tdep.c,v
retrieving revision 1.28
diff -u -p -r1.28 ppcnbsd-tdep.c
--- ppcnbsd-tdep.c	1 May 2006 15:10:26 -0000	1.28
+++ ppcnbsd-tdep.c	2 May 2006 19:29:26 -0000
@@ -1,6 +1,6 @@
-/* Target-dependent code for PowerPC systems running NetBSD.
+/* Target-dependent code for NetBSD/powerpc.
 
-   Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
 
    Contributed by Wasabi Systems, Inc.
 
@@ -22,225 +22,58 @@
    Boston, MA 02110-1301, USA.  */
 
 #include "defs.h"
-#include "gdbcore.h"
-#include "regcache.h"
-#include "target.h"
-#include "breakpoint.h"
-#include "value.h"
+#include "gdbtypes.h"
 #include "osabi.h"
+#include "regcache.h"
+#include "regset.h"
+#include "trad-frame.h"
+#include "tramp-frame.h"
+
+#include "gdb_assert.h"
+#include "gdb_string.h"
 
 #include "ppc-tdep.h"
 #include "ppcnbsd-tdep.h"
-#include "nbsd-tdep.h"
-#include "tramp-frame.h"
-#include "trad-frame.h"
-#include "gdb_assert.h"
 #include "solib-svr4.h"
 
-#define REG_FIXREG_OFFSET(x)	((x) * 4)
-#define REG_LR_OFFSET		(32 * 4)
-#define REG_CR_OFFSET		(33 * 4)
-#define REG_XER_OFFSET		(34 * 4)
-#define REG_CTR_OFFSET		(35 * 4)
-#define REG_PC_OFFSET		(36 * 4)
-#define SIZEOF_STRUCT_REG	(37 * 4)
-
-#define FPREG_FPR_OFFSET(x)	((x) * 8)
-#define FPREG_FPSCR_OFFSET	(32 * 8)
-#define SIZEOF_STRUCT_FPREG	(33 * 8)
-
-void
-ppcnbsd_supply_reg (char *regs, int regno)
-{
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
-  int i;
-
-  for (i = 0; i < ppc_num_gprs; i++)
-    {
-      if (regno == tdep->ppc_gp0_regnum + i || regno == -1)
-	regcache_raw_supply (current_regcache, tdep->ppc_gp0_regnum + i,
-			     regs + REG_FIXREG_OFFSET (i));
-    }
-
-  if (regno == tdep->ppc_lr_regnum || regno == -1)
-    regcache_raw_supply (current_regcache, tdep->ppc_lr_regnum,
-			 regs + REG_LR_OFFSET);
-
-  if (regno == tdep->ppc_cr_regnum || regno == -1)
-    regcache_raw_supply (current_regcache, tdep->ppc_cr_regnum,
-			 regs + REG_CR_OFFSET);
-
-  if (regno == tdep->ppc_xer_regnum || regno == -1)
-    regcache_raw_supply (current_regcache, tdep->ppc_xer_regnum,
-			 regs + REG_XER_OFFSET);
-
-  if (regno == tdep->ppc_ctr_regnum || regno == -1)
-    regcache_raw_supply (current_regcache, tdep->ppc_ctr_regnum,
-			 regs + REG_CTR_OFFSET);
-
-  if (regno == PC_REGNUM || regno == -1)
-    regcache_raw_supply (current_regcache, PC_REGNUM,
-			 regs + REG_PC_OFFSET);
-}
-
-void
-ppcnbsd_fill_reg (char *regs, int regno)
-{
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
-  int i;
-
-  for (i = 0; i < ppc_num_gprs; i++)
-    {
-      if (regno == tdep->ppc_gp0_regnum + i || regno == -1)
-	regcache_raw_collect (current_regcache, tdep->ppc_gp0_regnum + i,
-			      regs + REG_FIXREG_OFFSET (i));
-    }
+/* Register offsets from <machine/reg.h>.  */
+struct ppc_reg_offsets ppcnbsd_reg_offsets;
+
 
-  if (regno == tdep->ppc_lr_regnum || regno == -1)
-    regcache_raw_collect (current_regcache, tdep->ppc_lr_regnum,
-			  regs + REG_LR_OFFSET);
-
-  if (regno == tdep->ppc_cr_regnum || regno == -1)
-    regcache_raw_collect (current_regcache, tdep->ppc_cr_regnum,
-			  regs + REG_CR_OFFSET);
-
-  if (regno == tdep->ppc_xer_regnum || regno == -1)
-    regcache_raw_collect (current_regcache, tdep->ppc_xer_regnum,
-			  regs + REG_XER_OFFSET);
-
-  if (regno == tdep->ppc_ctr_regnum || regno == -1)
-    regcache_raw_collect (current_regcache, tdep->ppc_ctr_regnum,
-			  regs + REG_CTR_OFFSET);
+/* Core file support.  */
 
-  if (regno == PC_REGNUM || regno == -1)
-    regcache_raw_collect (current_regcache, PC_REGNUM, regs + REG_PC_OFFSET);
-}
+/* NetBSD/powerpc register set.  */
 
-void
-ppcnbsd_supply_fpreg (char *fpregs, int regno)
+struct regset ppcnbsd_gregset =
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
-  int i;
-
-  /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
-     point registers.  Traditionally, GDB's register set has still
-     listed the floating point registers for such machines, so this
-     code is harmless.  However, the new E500 port actually omits the
-     floating point registers entirely from the register set --- they
-     don't even have register numbers assigned to them.
-
-     It's not clear to me how best to update this code, so this assert
-     will alert the first person to encounter the NetBSD/E500
-     combination to the problem.  */
-  gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
-
-  for (i = 0; i < ppc_num_fprs; i++)
-    {
-      if (regno == tdep->ppc_fp0_regnum + i || regno == -1)
-	regcache_raw_supply (current_regcache, tdep->ppc_fp0_regnum + i,
-			     fpregs + FPREG_FPR_OFFSET (i));
-    }
-
-  if (regno == tdep->ppc_fpscr_regnum || regno == -1)
-    regcache_raw_supply (current_regcache, tdep->ppc_fpscr_regnum,
-			 fpregs + FPREG_FPSCR_OFFSET);
-}
+  &ppcnbsd_reg_offsets,
+  ppc_supply_gregset
+};
 
-void
-ppcnbsd_fill_fpreg (char *fpregs, int regno)
+struct regset ppcnbsd_fpregset =
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
-  int i;
-
-  /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
-     point registers.  Traditionally, GDB's register set has still
-     listed the floating point registers for such machines, so this
-     code is harmless.  However, the new E500 port actually omits the
-     floating point registers entirely from the register set --- they
-     don't even have register numbers assigned to them.
-
-     It's not clear to me how best to update this code, so this assert
-     will alert the first person to encounter the NetBSD/E500
-     combination to the problem.  */
-  gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
-
-  for (i = 0; i < ppc_num_fprs; i++)
-    {
-      if (regno == tdep->ppc_fp0_regnum + i || regno == -1)
-	regcache_raw_collect (current_regcache, tdep->ppc_fp0_regnum + i,
-			      fpregs + FPREG_FPR_OFFSET (i));
-    }
+  &ppcnbsd_reg_offsets,
+  ppc_supply_fpregset
+};
 
-  if (regno == tdep->ppc_fpscr_regnum || regno == -1)
-    regcache_raw_collect (current_regcache, tdep->ppc_fpscr_regnum,
-			  fpregs + FPREG_FPSCR_OFFSET);
-}
+/* Return the appropriate register set for the core section identified
+   by SECT_NAME and SECT_SIZE.  */
 
-static void
-fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which,
-                      CORE_ADDR ignore)
+static const struct regset *
+ppcnbsd_regset_from_core_section (struct gdbarch *gdbarch,
+				  const char *sect_name, size_t sect_size)
 {
-  char *regs, *fpregs;
-
-  /* We get everything from one section.  */
-  if (which != 0)
-    return;
-
-  regs = core_reg_sect;
-  fpregs = core_reg_sect + SIZEOF_STRUCT_REG;
+  if (strcmp (sect_name, ".reg") == 0 && sect_size >= 148)
+    return &ppcnbsd_gregset;
 
-  /* Integer registers.  */
-  ppcnbsd_supply_reg (regs, -1);
+  if (strcmp (sect_name, ".reg2") == 0 && sect_size >= 264)
+    return &ppcnbsd_fpregset;
 
-  /* Floating point registers.  */
-  ppcnbsd_supply_fpreg (fpregs, -1);
+  return NULL;
 }
+
 
-static void
-fetch_elfcore_registers (char *core_reg_sect, unsigned core_reg_size, int which,
-                         CORE_ADDR ignore)
-{
-  switch (which)
-    {
-    case 0:  /* Integer registers.  */
-      if (core_reg_size != SIZEOF_STRUCT_REG)
-	warning (_("Wrong size register set in core file."));
-      else
-	ppcnbsd_supply_reg (core_reg_sect, -1);
-      break;
-
-    case 2:  /* Floating point registers.  */
-      if (core_reg_size != SIZEOF_STRUCT_FPREG)
-	warning (_("Wrong size FP register set in core file."));
-      else
-	ppcnbsd_supply_fpreg (core_reg_sect, -1);
-      break;
-
-    default:
-      /* Don't know what kind of register request this is; just ignore it.  */
-      break;
-    }
-}
-
-static struct core_fns ppcnbsd_core_fns =
-{
-  bfd_target_unknown_flavour,		/* core_flavour */
-  default_check_format,			/* check_format */
-  default_core_sniffer,			/* core_sniffer */
-  fetch_core_registers,			/* core_read_registers */
-  NULL					/* next */
-};
-
-static struct core_fns ppcnbsd_elfcore_fns =
-{
-  bfd_target_elf_flavour,		/* core_flavour */
-  default_check_format,			/* check_format */
-  default_core_sniffer,			/* core_sniffer */
-  fetch_elfcore_registers,		/* core_read_registers */
-  NULL					/* next */
-};
-
-/* NetBSD is confused.  It appears that 1.5 was using the correct SVr4
+/* NetBSD is confused.  It appears that 1.5 was using the correct SVR4
    convention but, 1.6 switched to the below broken convention.  For
    the moment use the broken convention.  Ulgh!.  */
 
@@ -249,6 +82,7 @@ ppcnbsd_return_value (struct gdbarch *gd
 		      struct regcache *regcache, gdb_byte *readbuf,
 		      const gdb_byte *writebuf)
 {
+#if 0
   if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
        || TYPE_CODE (valtype) == TYPE_CODE_UNION)
       && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
@@ -259,9 +93,15 @@ ppcnbsd_return_value (struct gdbarch *gd
 	   || TYPE_LENGTH (valtype) == 8))
     return RETURN_VALUE_STRUCT_CONVENTION;
   else
+#endif
     return ppc_sysv_abi_broken_return_value (gdbarch, valtype, regcache,
 					     readbuf, writebuf);
 }
+
+
+/* Signal trampolines.  */
+
+static const struct tramp_frame ppcnbsd2_sigtramp;
 
 static void
 ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
@@ -269,53 +109,72 @@ ppcnbsd_sigtramp_cache_init (const struc
 			     struct trad_frame_cache *this_cache,
 			     CORE_ADDR func)
 {
-  CORE_ADDR base;
-  CORE_ADDR offset;
-  int i;
   struct gdbarch *gdbarch = get_frame_arch (next_frame);
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  CORE_ADDR addr, base;
+  int i;
 
   base = frame_unwind_register_unsigned (next_frame, SP_REGNUM);
-  offset = base + 0x18 + 2 * tdep->wordsize;
-  for (i = 0; i < ppc_num_gprs; i++)
+  if (self == &ppcnbsd2_sigtramp)
+    addr = base + 0x10 + 2 * tdep->wordsize;
+  else
+    addr = base + 0x18 + 2 * tdep->wordsize;
+  for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
     {
       int regnum = i + tdep->ppc_gp0_regnum;
-      trad_frame_set_reg_addr (this_cache, regnum, offset);
-      offset += tdep->wordsize;
+      trad_frame_set_reg_addr (this_cache, regnum, addr);
     }
-  trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, offset);
-  offset += tdep->wordsize;
-  trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, offset);
-  offset += tdep->wordsize;
-  trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, offset);
-  offset += tdep->wordsize;
-  trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, offset);
-  offset += tdep->wordsize;
-  trad_frame_set_reg_addr (this_cache, PC_REGNUM, offset); /* SRR0? */
-  offset += tdep->wordsize;
+  trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
+  addr += tdep->wordsize;
+  trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
+  addr += tdep->wordsize;
+  trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
+  addr += tdep->wordsize;
+  trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
+  addr += tdep->wordsize;
+  trad_frame_set_reg_addr (this_cache, PC_REGNUM, addr); /* SRR0? */
+  addr += tdep->wordsize;
 
   /* Construct the frame ID using the function start.  */
   trad_frame_set_id (this_cache, frame_id_build (base, func));
 }
 
-/* Given the NEXT frame, examine the instructions at and around this
-   frame's resume address (aka PC) to see of they look like a signal
-   trampoline.  Return the address of the trampolines first
-   instruction, or zero if it isn't a signal trampoline.  */
+static const struct tramp_frame ppcnbsd_sigtramp =
+{
+  SIGTRAMP_FRAME,
+  4,
+  {
+    { 0x3821fff0, -1 },		/* add r1,r1,-16 */
+    { 0x4e800021, -1 },		/* blrl */
+    { 0x38610018, -1 },		/* addi r3,r1,24 */
+    { 0x38000127, -1 },		/* li r0,295 */
+    { 0x44000002, -1 },		/* sc */
+    { 0x38000001, -1 },		/* li r0,1 */
+    { 0x44000002, -1 },		/* sc */
+    { TRAMP_SENTINEL_INSN, -1 }
+  },
+  ppcnbsd_sigtramp_cache_init
+};
+
+/* NetBSD 2.0 introduced a slightly different signal trampoline.  */
 
-static const struct tramp_frame ppcnbsd_sigtramp = {
+static const struct tramp_frame ppcnbsd2_sigtramp =
+{
   SIGTRAMP_FRAME,
-  4, /* insn size */
-  { /* insn */
-    { 0x38610018, -1 }, /* addi r3,r1,24 */
-    { 0x38000127, -1 }, /* li r0,295 */
-    { 0x44000002, -1 }, /* sc */
-    { 0x38000001, -1 }, /* li r0,1 */
-    { 0x44000002, -1 }, /* sc */
+  4,
+  {
+    { 0x3821fff0, -1 },		/* add r1,r1,-16 */
+    { 0x4e800021, -1 },		/* blrl */
+    { 0x38610010, -1 },		/* addi r3,r1,16 */
+    { 0x38000127, -1 },		/* li r0,295 */
+    { 0x44000002, -1 },		/* sc */
+    { 0x38000001, -1 },		/* li r0,1 */
+    { 0x44000002, -1 },		/* sc */
     { TRAMP_SENTINEL_INSN, -1 }
   },
   ppcnbsd_sigtramp_cache_init
 };
+
 
 static void
 ppcnbsd_init_abi (struct gdbarch_info info,
@@ -324,10 +183,21 @@ ppcnbsd_init_abi (struct gdbarch_info in
   /* For NetBSD, this is an on again, off again thing.  Some systems
      do use the broken struct convention, and some don't.  */
   set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
-  set_solib_svr4_fetch_link_map_offsets (gdbarch,
-                                nbsd_ilp32_solib_svr4_fetch_link_map_offsets);
+
+  /* NetBSD uses SVR4-style shared libraries.  */
+  set_solib_svr4_fetch_link_map_offsets
+    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+
+  set_gdbarch_regset_from_core_section
+    (gdbarch, ppcnbsd_regset_from_core_section);
+
   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
+  tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd2_sigtramp);
 }
+
+
+/* Provide a prototype to silence -Wmissing-prototypes.  */
+void _initialize_ppcnbsd_tdep (void);
 
 void
 _initialize_ppcnbsd_tdep (void)
@@ -335,6 +205,27 @@ _initialize_ppcnbsd_tdep (void)
   gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD_ELF,
 			  ppcnbsd_init_abi);
 
-  deprecated_add_core_fns (&ppcnbsd_core_fns);
-  deprecated_add_core_fns (&ppcnbsd_elfcore_fns);
+  /* Avoid initializing the register offsets again if they were
+     already initailized by ppcnbsd-nat.c.  */
+  if (ppcnbsd_reg_offsets.pc_offset == 0)
+    {
+      /* General-purpose registers.  */
+      ppcnbsd_reg_offsets.r0_offset = 0;
+      ppcnbsd_reg_offsets.lr_offset = 128;
+      ppcnbsd_reg_offsets.cr_offset = 132;
+      ppcnbsd_reg_offsets.xer_offset = 136;
+      ppcnbsd_reg_offsets.ctr_offset = 140;
+      ppcnbsd_reg_offsets.pc_offset = 144;
+      ppcnbsd_reg_offsets.ps_offset = -1;
+      ppcnbsd_reg_offsets.mq_offset = -1;
+
+      /* Floating-point registers.  */
+      ppcnbsd_reg_offsets.f0_offset = 0;
+      ppcnbsd_reg_offsets.fpscr_offset = 256;
+
+      /* AltiVec registers.  */
+      ppcnbsd_reg_offsets.vr0_offset = 0;
+      ppcnbsd_reg_offsets.vrsave_offset = 512;
+      ppcnbsd_reg_offsets.vscr_offset = 524;
+    }
 }
Index: ppcnbsd-tdep.h
===================================================================
RCS file: /cvs/src/src/gdb/ppcnbsd-tdep.h,v
retrieving revision 1.2
diff -u -p -r1.2 ppcnbsd-tdep.h
--- ppcnbsd-tdep.h	17 Dec 2005 22:34:01 -0000	1.2
+++ ppcnbsd-tdep.h	2 May 2006 19:29:26 -0000
@@ -1,5 +1,6 @@
-/* Common target dependent code for GDB on PowerPC systems running NetBSD.
-   Copyright (C) 2002 Free Software Foundation, Inc.
+/* Target-dependent code for NetBSD/powerpc.
+
+   Copyright (C) 2004, 2005 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -21,10 +22,15 @@
 #ifndef PPCNBSD_TDEP_H
 #define PPCNBSD_TDEP_H
 
-void ppcnbsd_supply_reg (char *, int);
-void ppcnbsd_fill_reg (char *, int);
+#include <stddef.h>
+
+struct regset;
+
+/* Register offsets for NetBSD/powerpc.  */
+extern struct ppc_reg_offsets ppcnbsd_reg_offsets;
 
-void ppcnbsd_supply_fpreg (char *, int);
-void ppcnbsd_fill_fpreg (char *, int);
+/* Register sets for NetBSD/powerpc.  */
+extern struct regset ppcnbsd_gregset;
+extern struct regset ppcnbsd_fpregset;
 
-#endif /* PPCNBSD_TDEP_H */
+#endif /* ppcnbsd-tdep.h */
Index: config/powerpc/nbsd.mh
===================================================================
RCS file: /cvs/src/src/gdb/config/powerpc/nbsd.mh,v
retrieving revision 1.15
diff -u -p -r1.15 nbsd.mh
--- config/powerpc/nbsd.mh	1 Oct 2004 17:26:14 -0000	1.15
+++ config/powerpc/nbsd.mh	2 May 2006 19:29:26 -0000
@@ -1,5 +1,4 @@
-# Host: PowerPC, running NetBSD
-NATDEPFILES= fork-child.o inf-ptrace.o infptrace.o ppcnbsd-nat.o bsd-kvm.o
-NAT_FILE= config/nm-nbsd.h
+# Host: NetBSD/powerpc
+NATDEPFILES= fork-child.o inf-ptrace.o ppcnbsd-nat.o bsd-kvm.o
 
 LOADLIBES= -lkvm
Index: config/powerpc/nbsd.mt
===================================================================
RCS file: /cvs/src/src/gdb/config/powerpc/nbsd.mt,v
retrieving revision 1.13
diff -u -p -r1.13 nbsd.mt
--- config/powerpc/nbsd.mt	13 Sep 2004 20:55:41 -0000	1.13
+++ config/powerpc/nbsd.mt	2 May 2006 19:29:26 -0000
@@ -1,6 +1,6 @@
-# Target: PowerPC, running NetBSD
-TDEPFILES= rs6000-tdep.o ppc-sysv-tdep.o ppcnbsd-tdep.o nbsd-tdep.o corelow.o \
-	solib.o solib-svr4.o
+# Target: NetBSD/powerpc
+TDEPFILES= rs6000-tdep.o ppc-sysv-tdep.o ppcnbsd-tdep.o \
+	corelow.o solib.o solib-svr4.o
 DEPRECATED_TM_FILE= tm-ppc-eabi.h
 
 SIM_OBS = remote-sim.o