MIPS/Linux support

11 files changed, 628 insertions, 0 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index bb8f62b..ecfed22 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,16 @@
+2001-07-10  Daniel Jacobowitz  <drow@mvista.com>
+
+	* mips-linux-tdep.c: New file.
+	* mips-linux-nat.c: New file.
+	* config/mips/linux.mh: New file.
+	* config/mips/linux.mt: New file.
+	* config/mips/xm-linux.h: New file.
+	* config/mips/nm-linux.h: New file.
+	* config/mips/tm-linux.h: New file.
+	* configure.host: Recognize mips*-*-linux*.
+	* configure.tgt: Likewise.
+	* NEWS: Mention mips*-*-linux* port.
+
 2001-07-09  Andrew Cagney  <ac131313@redhat.com>
 
 	* serial.h (struct serial): Rename `struct _serial_t'.
diff --git a/gdb/NEWS b/gdb/NEWS
index 816cf4c..d8af4c4 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -14,6 +14,7 @@ revised and enabled.
 
 Alpha FreeBSD					alpha*-*-freebsd*
 x86 FreeBSD 3.x and 4.x				i[3456]86*-freebsd[34]*
+MIPS Linux					mips*-*-linux*
 
 * New targets
 
diff --git a/gdb/config/mips/linux.mh b/gdb/config/mips/linux.mh
new file mode 100644
index 0000000..1a4b45f
--- /dev/null
+++ b/gdb/config/mips/linux.mh
@@ -0,0 +1,8 @@
+# Host: Linux/MIPS
+XDEPFILES=
+XM_FILE= xm-linux.h
+NAT_FILE= nm-linux.h
+NATDEPFILES= infptrace.o inftarg.o fork-child.o mips-linux-nat.o \
+	thread-db.o lin-lwp.o proc-service.o
+
+LOADLIBES = -ldl -rdynamic
diff --git a/gdb/config/mips/linux.mt b/gdb/config/mips/linux.mt
new file mode 100644
index 0000000..16f8e32
--- /dev/null
+++ b/gdb/config/mips/linux.mt
@@ -0,0 +1,9 @@
+# Target: Linux/MIPS
+TDEPFILES= mips-tdep.o mips-linux-tdep.o corelow.o \
+	solib.o solib-svr4.o
+TM_FILE= tm-linux.h
+
+GDBSERVER_DEPFILES= low-linux.o
+
+SIM_OBS = remote-sim.o
+SIM = ../sim/mips/libsim.a
diff --git a/gdb/config/mips/nm-linux.h b/gdb/config/mips/nm-linux.h
new file mode 100644
index 0000000..27fb1b1
--- /dev/null
+++ b/gdb/config/mips/nm-linux.h
@@ -0,0 +1,66 @@
+/* Native-dependent definitions for Linux/MIPS.
+   Copyright 1996, 2001 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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 2 of the License, or
+   (at your option) any later version.
+
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef NM_MIPSLINUX_H
+#define NM_MIPSLINUX_H
+
+#define MIPS_GNULINUX_TARGET
+
+#include "nm-linux.h"
+
+/* Return sizeof user struct to callers in less machine dependent
+   routines.  Hard coded for cross-compilation friendliness. */
+
+#define KERNEL_U_SIZE 504
+
+/* ptrace register ``addresses'' are absolute.  */
+
+#define U_REGS_OFFSET 0
+
+/* ptrace transfers longs, and expects addresses as longs.  */
+
+#define PTRACE_ARG3_TYPE long
+#define PTRACE_XFER_TYPE long
+
+#define REGISTER_U_ADDR(addr, blockend, regno) \
+  (addr) = mips_register_addr ((regno),(blockend))
+
+int mips_linux_cannot_fetch_register (int regno);
+int mips_linux_cannot_store_register (int regno);
+#define CANNOT_FETCH_REGISTER(regno) mips_linux_cannot_fetch_register (regno)
+#define CANNOT_STORE_REGISTER(regno) mips_linux_cannot_store_register (regno)
+
+/* FIXME: This should be moved to ../nm-linux.h once we have converted all
+   Linux targets to use the new threads stuff (without the #undef of
+   course).  */
+
+extern int lin_lwp_prepare_to_proceed (void);
+#undef PREPARE_TO_PROCEED
+#define PREPARE_TO_PROCEED(select_it) lin_lwp_prepare_to_proceed ()
+
+extern void lin_lwp_attach_lwp (ptid_t ptid, int verbose);
+#define ATTACH_LWP(ptid, verbose) lin_lwp_attach_lwp ((ptid), (verbose))
+
+#include <signal.h>
+
+extern void lin_thread_get_thread_signals (sigset_t *mask);
+#define GET_THREAD_SIGNALS(mask) lin_thread_get_thread_signals (mask)
+
+#endif /* NM_MIPSLINUX_H */
diff --git a/gdb/config/mips/tm-linux.h b/gdb/config/mips/tm-linux.h
new file mode 100644
index 0000000..54725fd
--- /dev/null
+++ b/gdb/config/mips/tm-linux.h
@@ -0,0 +1,90 @@
+/* Target-dependent definitions for Linux/MIPS.
+   Copyright 2001 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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 2 of the License, or
+   (at your option) any later version.
+
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef TM_MIPSLINUX_H
+#define TM_MIPSLINUX_H
+
+#include "mips/tm-mips.h"
+
+/* We don't want to inherit tm-mips.h's shared library trampoline code.  */
+
+#undef IN_SOLIB_CALL_TRAMPOLINE
+#undef IN_SOLIB_RETURN_TRAMPOLINE
+#undef SKIP_TRAMPOLINE_CODE
+#undef IGNORE_HELPER_CALL
+
+/* FIXME: Do not include "tm-linux.h", because we do not want the host's
+   <signal.h>.  Instead, copy the non-signal bits for now.  */
+
+/* We need this file for the SOLIB_TRAMPOLINE stuff.  */
+
+#include "tm-sysv4.h"
+
+/* We define SVR4_SHARED_LIBS unconditionally, on the assumption that
+   link.h is available on all linux platforms.  For I386 and SH3/4,
+   we hard-code the information rather than use link.h anyway (for
+   the benefit of cross-debugging).  We may move to doing that for
+   other architectures as well.  */
+
+#define SVR4_SHARED_LIBS
+#include "solib.h"              /* Support for shared libraries.  */
+
+/* End from "tm-linux.h".  */
+
+/* There's an E_MIPS_ABI_O32 flag in e_flags, but we don't use it - in
+   fact, using it may violate the o32 ABI.  */
+
+#define MIPS_DEFAULT_ABI MIPS_ABI_O32
+
+/* Linux/MIPS has __SIGRTMAX == 127.  */
+
+#define REALTIME_LO 32
+#define REALTIME_HI 128
+
+/* Use target_specific function to define link map offsets.  */
+
+extern struct link_map_offsets *mips_linux_svr4_fetch_link_map_offsets (void);
+#define SVR4_FETCH_LINK_MAP_OFFSETS() \
+  mips_linux_svr4_fetch_link_map_offsets ()
+
+/* Details about jmp_buf.  */
+
+#define JB_ELEMENT_SIZE 4
+#define JB_PC 0
+
+/* Figure out where the longjmp will land.  Slurp the arguments 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 ADDR.  This routine returns 1 on success.  */
+
+#define GET_LONGJMP_TARGET(ADDR) mips_linux_get_longjmp_target(ADDR)
+extern int mips_linux_get_longjmp_target (CORE_ADDR *);
+
+/* We do single stepping in software.  */
+
+#define SOFTWARE_SINGLE_STEP_P() 1
+#define SOFTWARE_SINGLE_STEP(sig,bp_p) mips_software_single_step (sig, bp_p)
+
+/* FIXME: This still needs to be implemented.  */
+
+#undef  IN_SIGTRAMP
+#define IN_SIGTRAMP(pc, name)	(0)
+
+#endif /* TM_MIPSLINUX_H */
diff --git a/gdb/config/mips/xm-linux.h b/gdb/config/mips/xm-linux.h
new file mode 100644
index 0000000..d28578b
--- /dev/null
+++ b/gdb/config/mips/xm-linux.h
@@ -0,0 +1,36 @@
+/* Host definitions for Linux/MIPS.
+   Copyright 2001 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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 2 of the License, or
+   (at your option) any later version.
+
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef XM_MIPSLINUX_H
+#define XM_MIPSLINUX_H
+
+#ifndef HOST_BYTE_ORDER
+#include <endian.h>
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define HOST_BYTE_ORDER BIG_ENDIAN
+#else
+#define HOST_BYTE_ORDER LITTLE_ENDIAN
+#endif
+#endif
+
+/* Need R_OK etc, but USG isn't defined.  */
+#include <unistd.h>
+
+#endif /* XM_MIPSLINUX_H */
diff --git a/gdb/configure.host b/gdb/configure.host
index c7268fe..403957b 100644
--- a/gdb/configure.host
+++ b/gdb/configure.host
@@ -16,6 +16,7 @@ hppa*)			gdb_host_cpu=pa ;;
 i[3456]86*)		gdb_host_cpu=i386 ;;
 m68*)			gdb_host_cpu=m68k ;;
 m88*)			gdb_host_cpu=m88k ;;
+mips*)			gdb_host_cpu=mips ;;
 powerpc*)		gdb_host_cpu=powerpc ;;
 sparc64)		gdb_host_cpu=sparc ;;
 s390*)			gdb_host_cpu=s390 ;;
@@ -118,6 +119,7 @@ mips-sgi-irix4*)	gdb_host=irix4 ;;
 mips-sgi-irix5*)	gdb_host=irix5 ;;
 mips-sgi-irix6*)	gdb_host=irix6 ;;
 mips-sony-*)		gdb_host=news-mips ;;
+mips*-*-linux*)		gdb_host=linux ;;
 mips-*-mach3*)		gdb_host=mipsm3 ;;
 mips-*-sysv4*)		gdb_host=mipsv4 ;;
 mips-*-sysv*)		gdb_host=riscos ;;
diff --git a/gdb/configure.tgt b/gdb/configure.tgt
index b9f1d17..57cc210 100644
--- a/gdb/configure.tgt
+++ b/gdb/configure.tgt
@@ -211,6 +211,7 @@ mips*-sgi-irix5*)	gdb_target=irix5 ;;
 mips*-sgi-irix6*)	gdb_target=irix6 ;;
 mips*-sgi-*)		gdb_target=irix3 ;;
 mips*-sony-*)		gdb_target=bigmips ;;
+mips*-*-linux*)		gdb_target=linux ;;
 mips*-*-mach3*)		gdb_target=mipsm3 ;;
 mips*-*-sysv4*)		gdb_target=mipsv4 ;;
 mips*-*-sysv*)		gdb_target=bigmips ;;
diff --git a/gdb/mips-linux-nat.c b/gdb/mips-linux-nat.c
new file mode 100644
index 0000000..3c2b159
--- /dev/null
+++ b/gdb/mips-linux-nat.c
@@ -0,0 +1,58 @@
+/* Native-dependent code for Linux/MIPS.
+   Copyright 2001 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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 2 of the License, or
+   (at your option) any later version.
+
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include "defs.h"
+
+/* Pseudo registers can not be read.  ptrace does not provide a way to
+   read (or set) PS_REGNUM, and there's no point in reading or setting
+   ZERO_REGNUM.  We also can not set BADVADDR, CAUSE, or FCRIR via
+   ptrace().  */
+
+int
+mips_linux_cannot_fetch_register (int regno)
+{
+  if (regno >= FP_REGNUM)
+    return 1;
+  else if (regno == PS_REGNUM)
+    return 1;
+  else if (regno == ZERO_REGNUM)
+    return 1;
+  else
+    return 0;
+}
+
+int
+mips_linux_cannot_store_register (int regno)
+{
+  if (regno >= FP_REGNUM)
+    return 1;
+  else if (regno == PS_REGNUM)
+    return 1;
+  else if (regno == ZERO_REGNUM)
+    return 1;
+  else if (regno == BADVADDR_REGNUM)
+    return 1;
+  else if (regno == CAUSE_REGNUM)
+    return 1;
+  else if (regno == FCRIR_REGNUM)
+    return 1;
+  else
+    return 0;
+}
diff --git a/gdb/mips-linux-tdep.c b/gdb/mips-linux-tdep.c
new file mode 100644
index 0000000..5b58348
--- /dev/null
+++ b/gdb/mips-linux-tdep.c
@@ -0,0 +1,344 @@
+/* Target-dependent code for Linux/MIPS.
+   Copyright 2001 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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 2 of the License, or
+   (at your option) any later version.
+
+   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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include "defs.h"
+#include "gdbcore.h"
+#include "target.h"
+#include "solib-svr4.h"
+
+/* Copied from <asm/elf.h>.  */
+#define ELF_NGREG       45
+#define ELF_NFPREG      33
+
+typedef unsigned char elf_greg_t[4];
+typedef elf_greg_t elf_gregset_t[ELF_NGREG];
+
+typedef unsigned char elf_fpreg_t[8];
+typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
+
+/* 0 - 31 are integer registers, 32 - 63 are fp registers.  */
+#define FPR_BASE        32
+#define PC              64
+#define CAUSE           65
+#define BADVADDR        66
+#define MMHI            67
+#define MMLO            68
+#define FPC_CSR         69
+#define FPC_EIR         70
+
+#define EF_REG0			6
+#define EF_REG31		37
+#define EF_LO			38
+#define EF_HI			39
+#define EF_CP0_EPC		40
+#define EF_CP0_BADVADDR		41
+#define EF_CP0_STATUS		42
+#define EF_CP0_CAUSE		43
+
+#define EF_SIZE			180
+
+/* Figure out where the longjmp will land.
+   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 1 on success.  */
+
+int
+mips_linux_get_longjmp_target (CORE_ADDR *pc)
+{
+  CORE_ADDR jb_addr;
+  char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
+
+  jb_addr = read_register (A0_REGNUM);
+
+  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;
+}
+
+/* Unpack an elf_gregset_t into GDB's register cache.  */
+
+void 
+supply_gregset (elf_gregset_t *gregsetp)
+{
+  int regi;
+  elf_greg_t *regp = *gregsetp;
+  static char zerobuf[MAX_REGISTER_RAW_SIZE] = {0};
+
+  for (regi = EF_REG0; regi <= EF_REG31; regi++)
+    supply_register ((regi - EF_REG0), (char *)(regp + regi));
+
+  supply_register (LO_REGNUM, (char *)(regp + EF_LO));
+  supply_register (HI_REGNUM, (char *)(regp + EF_HI));
+
+  supply_register (PC_REGNUM, (char *)(regp + EF_CP0_EPC));
+  supply_register (BADVADDR_REGNUM, (char *)(regp + EF_CP0_BADVADDR));
+  supply_register (PS_REGNUM, (char *)(regp + EF_CP0_STATUS));
+  supply_register (CAUSE_REGNUM, (char *)(regp + EF_CP0_CAUSE));
+
+  /* Fill inaccessible registers with zero.  */
+  supply_register (FP_REGNUM, zerobuf);
+  supply_register (UNUSED_REGNUM, zerobuf);
+  for (regi = FIRST_EMBED_REGNUM; regi < LAST_EMBED_REGNUM; regi++)
+    supply_register (regi, zerobuf);
+}
+
+/* Pack our registers (or one register) into an elf_gregset_t.  */
+
+void
+fill_gregset (elf_gregset_t *gregsetp, int regno)
+{
+  int regaddr, regi;
+  elf_greg_t *regp = *gregsetp;
+  void *src, *dst;
+
+  if (regno == -1)
+    {
+      memset (regp, 0, sizeof (elf_gregset_t));
+      for (regi = 0; regi < 32; regi++)
+        fill_gregset (gregsetp, regi);
+      fill_gregset (gregsetp, LO_REGNUM);
+      fill_gregset (gregsetp, HI_REGNUM);
+      fill_gregset (gregsetp, PC_REGNUM);
+      fill_gregset (gregsetp, BADVADDR_REGNUM);
+      fill_gregset (gregsetp, PS_REGNUM);
+      fill_gregset (gregsetp, CAUSE_REGNUM);
+
+      return;
+   }
+
+  if (regno < 32)
+    {
+      src = &registers[REGISTER_BYTE (regno)];
+      dst = regp + regno + EF_REG0;
+      memcpy (dst, src, sizeof (elf_greg_t));
+      return;
+    }
+
+  regaddr = -1;
+  switch (regno)
+    {
+      case LO_REGNUM:
+	regaddr = EF_LO;
+	break;
+      case HI_REGNUM:
+	regaddr = EF_HI;
+	break;
+      case PC_REGNUM:
+	regaddr = EF_CP0_EPC;
+	break;
+      case BADVADDR_REGNUM:
+	regaddr = EF_CP0_BADVADDR;
+	break;
+      case PS_REGNUM:
+	regaddr = EF_CP0_STATUS;
+	break;
+      case CAUSE_REGNUM:
+	regaddr = EF_CP0_CAUSE;
+	break;
+    }
+
+  if (regaddr != -1)
+    {
+      src = &registers[REGISTER_BYTE (regno)];
+      dst = regp + regaddr;
+      memcpy (dst, src, sizeof (elf_greg_t));
+    }
+}
+
+/* Likewise, unpack an elf_fpregset_t.  */
+
+void
+supply_fpregset (elf_fpregset_t *fpregsetp)
+{
+  register int regi;
+  static char zerobuf[MAX_REGISTER_RAW_SIZE] = {0};
+
+  for (regi = 0; regi < 32; regi++)
+    supply_register (FP0_REGNUM + regi,
+		     (char *)(*fpregsetp + regi));
+
+  supply_register (FCRCS_REGNUM, (char *)(*fpregsetp + 32));
+
+  /* FIXME: how can we supply FCRIR_REGNUM?  The ABI doesn't tell us. */
+  supply_register (FCRIR_REGNUM, zerobuf);
+}
+
+/* Likewise, pack one or all floating point registers into an
+   elf_fpregset_t.  */
+
+void
+fill_fpregset (elf_fpregset_t *fpregsetp, int regno)
+{
+  char *from, *to;
+
+  if ((regno >= FP0_REGNUM) && (regno < FP0_REGNUM + 32))
+    {
+      from = (char *) &registers[REGISTER_BYTE (regno)];
+      to = (char *) (*fpregsetp + regno - FP0_REGNUM);
+      memcpy (to, from, REGISTER_RAW_SIZE (regno - FP0_REGNUM));
+    }
+  else if (regno == FCRCS_REGNUM)
+    {
+      from = (char *) &registers[REGISTER_BYTE (regno)];
+      to = (char *) (*fpregsetp + 32);
+      memcpy (to, from, REGISTER_RAW_SIZE (regno));
+    }
+  else if (regno == -1)
+    {
+      int regi;
+
+      for (regi = 0; regi < 32; regi++)
+	fill_fpregset (fpregsetp, FP0_REGNUM + regi);
+      fill_fpregset(fpregsetp, FCRCS_REGNUM);
+    }
+}
+
+/* Map gdb internal register number to ptrace ``address''.
+   These ``addresses'' are normally defined in <asm/ptrace.h>.  */
+
+CORE_ADDR
+register_addr (int regno, CORE_ADDR blockend)
+{
+  int regaddr;
+
+  if (regno < 0 || regno >= NUM_REGS)
+    error ("Bogon register number %d.", regno);
+
+  if (regno < 32)
+    regaddr = regno;
+  else if ((regno >= FP0_REGNUM) && (regno < FP0_REGNUM + 32))
+    regaddr = FPR_BASE + (regno - FP0_REGNUM);
+  else if (regno == PC_REGNUM)
+    regaddr = PC;
+  else if (regno == CAUSE_REGNUM)
+    regaddr = CAUSE;
+  else if (regno == BADVADDR_REGNUM)
+    regaddr = BADVADDR;
+  else if (regno == LO_REGNUM)
+    regaddr = MMLO;
+  else if (regno == HI_REGNUM)
+    regaddr = MMHI;
+  else if (regno == FCRCS_REGNUM)
+    regaddr = FPC_CSR;
+  else if (regno == FCRIR_REGNUM)
+    regaddr = FPC_EIR;
+  else
+    error ("Unknowable register number %d.", regno);
+
+  return regaddr;
+}
+
+/*  Use a local version of this function to get the correct types for
+    regsets, until multi-arch core support is ready.  */
+
+static void
+fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
+		      int which, CORE_ADDR reg_addr)
+{
+  elf_gregset_t gregset;
+  elf_fpregset_t fpregset;
+
+  if (which == 0)
+    {
+      if (core_reg_size != sizeof (gregset))
+	{
+	  warning ("wrong size gregset struct in core file");
+	}
+      else
+	{
+	  memcpy ((char *) &gregset, core_reg_sect, sizeof (gregset));
+	  supply_gregset (&gregset);
+	}
+    }
+  else if (which == 2)
+    {
+      if (core_reg_size != sizeof (fpregset))
+	{
+	  warning ("wrong size fpregset struct in core file");
+	}
+      else
+	{
+	  memcpy ((char *) &fpregset, core_reg_sect, sizeof (fpregset));
+	  supply_fpregset (&fpregset);
+	}
+    }
+}
+
+/* Register that we are able to handle ELF file formats using standard
+   procfs "regset" structures.  */
+
+static struct core_fns regset_core_fns =
+{
+  bfd_target_elf_flavour,		/* core_flavour */
+  default_check_format,			/* check_format */
+  default_core_sniffer,			/* core_sniffer */
+  fetch_core_registers,			/* core_read_registers */
+  NULL					/* next */
+};
+
+/* Fetch (and possibly build) an appropriate link_map_offsets
+   structure for native Linux/MIPS targets using the struct offsets
+   defined in link.h (but without actual reference to that file).
+
+   This makes it possible to access Linux/MIPS shared libraries from a
+   GDB that was not built on an Linux/MIPS host (for cross debugging).  */
+
+struct link_map_offsets *
+mips_linux_svr4_fetch_link_map_offsets (void)
+{ 
+  static struct link_map_offsets lmo;
+  static struct link_map_offsets *lmp = NULL;
+
+  if (lmp == NULL)
+    { 
+      lmp = &lmo;
+
+      lmo.r_debug_size = 8;	/* The actual size is 20 bytes, but
+				   this is all we need.  */
+      lmo.r_map_offset = 4;
+      lmo.r_map_size   = 4;
+
+      lmo.link_map_size = 20;
+
+      lmo.l_addr_offset = 0;
+      lmo.l_addr_size   = 4;
+
+      lmo.l_name_offset = 4;
+      lmo.l_name_size   = 4;
+
+      lmo.l_next_offset = 12;
+      lmo.l_next_size   = 4;
+
+      lmo.l_prev_offset = 16;
+      lmo.l_prev_size   = 4;
+    }
+
+  return lmp;
+}
+
+void
+_initialize_mips_linux_tdep ()
+{
+  add_core_fns (&regset_core_fns);
+}