2004-04-24 Randolph Chung <tausq@debian.org>

	* configure.host (hppa*-*-linux*): New target.
	* configure.tgt (hppa*-*-linux*): Likewise.
	* hppa-tdep.c (hppa_gdbarch_init): Set cannot_fetch_register, move
	gdbarch_init_osabi() call earlier so that osabi-specific frame
	unwinders can be registered first.
	* config/djgpp/fnchange.lst: Add entries for hppa-linux-tdep.c and
	hppa-linux-nat.c.
	* config/pa/tm-hppa.h (ISR_REGNUM, PID0_REGNUM, PID1_REGNUM)
	(PID2_REGNUM, PID3_REGNUM): Add definitions of some register numbers.
	* config/pa/linux.mh: New file.
	* config/pa/linux.mt: New file.
	* config/pa/nm-linux.h: New file.
	* config/pa/xm-linux.h: New file.
	* hppa-linux-nat.c: New file.
	* hppa-linux-tdep.c: New file.

12 files changed, 879 insertions, 3 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index aa65b7a21b9..fcfcbcfae2e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,21 @@
+2004-04-24  Randolph Chung  <tausq@debian.org>
+
+	* configure.host (hppa*-*-linux*): New target.
+	* configure.tgt (hppa*-*-linux*): Likewise.
+	* hppa-tdep.c (hppa_gdbarch_init): Set cannot_fetch_register, move
+	gdbarch_init_osabi() call earlier so that osabi-specific frame
+	unwinders can be registered first.
+	* config/djgpp/fnchange.lst: Add entries for hppa-linux-tdep.c and
+	hppa-linux-nat.c.
+	* config/pa/tm-hppa.h (ISR_REGNUM, PID0_REGNUM, PID1_REGNUM)
+	(PID2_REGNUM, PID3_REGNUM): Add definitions of some register numbers.
+	* config/pa/linux.mh: New file.
+	* config/pa/linux.mt: New file.
+	* config/pa/nm-linux.h: New file.
+	* config/pa/xm-linux.h: New file.
+	* hppa-linux-nat.c: New file.
+	* hppa-linux-tdep.c: New file.
+
 2004-04-28  Randolph Chung  <tausq@debian.org>
 
 	* hppa-tdep.c (hppa32_return_value): Handle both 4- and 8-byte fp
diff --git a/gdb/config/djgpp/fnchange.lst b/gdb/config/djgpp/fnchange.lst
index 1d9e3936eee..4950a63be9b 100644
--- a/gdb/config/djgpp/fnchange.lst
+++ b/gdb/config/djgpp/fnchange.lst
@@ -232,6 +232,8 @@
 @V@/gdb/testsuite/gdb.mi/mi2-var-display.exp @V@/gdb/testsuite/gdb.mi/mi2vardisplay.exp
 @V@/gdb/amd64-linux-tdep.c @V@/gdb/amd64-ltdep.c
 @V@/gdb/amd64-linux-nat.c @V@/gdb/amd64-lnat.c
+@V@/gdb/hppa-linux-tdep.c @V@/gdb/palnxtdep.c
+@V@/gdb/hppa-linux-nat.c @V@/gdb/palnxnat.c
 @V@/include/ChangeLog-9103 @V@/include/ChangeLog.9103
 @V@/include/coff/ChangeLog-9103 @V@/include/coff/ChangeLog.9103
 @V@/include/elf/ChangeLog-9103 @V@/include/elf/ChangeLog.9103
diff --git a/gdb/config/pa/linux.mh b/gdb/config/pa/linux.mh
new file mode 100644
index 00000000000..232a4adaeb4
--- /dev/null
+++ b/gdb/config/pa/linux.mh
@@ -0,0 +1,9 @@
+# Host: Hewlett-Packard PA-RISC machine, running Linux
+XDEPFILES=
+XM_FILE= xm-linux.h
+NAT_FILE= nm-linux.h
+NATDEPFILES= infptrace.o inftarg.o fork-child.o corelow.o gcore.o \
+	core-regset.o hppa-linux-nat.o linux-proc.o \
+	proc-service.o thread-db.o lin-lwp.o linux-nat.o
+
+LOADLIBES = -ldl -rdynamic
diff --git a/gdb/config/pa/linux.mt b/gdb/config/pa/linux.mt
new file mode 100644
index 00000000000..cb67725423c
--- /dev/null
+++ b/gdb/config/pa/linux.mt
@@ -0,0 +1,3 @@
+# Target: HP PA-RISC running Linux
+TDEPFILES= hppa-tdep.o hppa-linux-tdep.o glibc-tdep.o solib.o solib-svr4.o
+TM_FILE=tm-hppa.h
diff --git a/gdb/config/pa/nm-linux.h b/gdb/config/pa/nm-linux.h
new file mode 100644
index 00000000000..ee88ba7cd90
--- /dev/null
+++ b/gdb/config/pa/nm-linux.h
@@ -0,0 +1,29 @@
+/* Native support for GNU/Linux, for GDB, the GNU debugger.
+   Copyright (C) 2004 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 PA_NM_LINUX_H
+#define PA_NM_LINUX_H
+
+#include "config/nm-linux.h"
+
+#define U_REGS_OFFSET 0
+
+#endif
+
diff --git a/gdb/config/pa/tm-hppa.h b/gdb/config/pa/tm-hppa.h
index a8037194dae..7413684f5bf 100644
--- a/gdb/config/pa/tm-hppa.h
+++ b/gdb/config/pa/tm-hppa.h
@@ -52,9 +52,14 @@ extern int hppa_pc_requires_run_before_use (CORE_ADDR pc);
 #define PCSQ_TAIL_REGNUM 36	/* instruction space queue tail */
 #define EIEM_REGNUM 37		/* External Interrupt Enable Mask */
 #define IIR_REGNUM 38		/* Interrupt Instruction Register */
+#define ISR_REGNUM 39		/* Interrupt Space Register */
 #define IOR_REGNUM 40		/* Interrupt Offset Register */
 #define SR4_REGNUM 43		/* space register 4 */
 #define RCR_REGNUM 51		/* Recover Counter (also known as cr0) */
+#define PID0_REGNUM 52		/* Protection ID */
+#define PID1_REGNUM 53		/* Protection ID */
+#define PID2_REGNUM 55		/* Protection ID */
+#define PID3_REGNUM 56		/* Protection ID */
 #define CCR_REGNUM 54		/* Coprocessor Configuration Register */
 #define TR0_REGNUM 57		/* Temporary Registers (cr24 -> cr31) */
 #define CR27_REGNUM 60		/* Base register for thread-local storage, cr27 */
diff --git a/gdb/config/pa/xm-linux.h b/gdb/config/pa/xm-linux.h
new file mode 100644
index 00000000000..ceb6ed2cae5
--- /dev/null
+++ b/gdb/config/pa/xm-linux.h
@@ -0,0 +1,31 @@
+/* Host-dependent definitions for the hppa-linux.
+
+   Copyright 2004 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_HPPA_LINUX_H
+#define XM_HPPA_LINUX_H
+
+#include "floatformat.h"
+
+#define HOST_FLOAT_FORMAT &floatformat_ieee_single_big
+#define HOST_DOUBLE_FORMAT &floatformat_ieee_double_big
+#define HOST_LONG_DOUBLE_FORMAT &floatformat_ieee_double_big
+
+#endif /* xm-linux.h */
diff --git a/gdb/configure.host b/gdb/configure.host
index 64d46bd4c65..8839dc4395a 100644
--- a/gdb/configure.host
+++ b/gdb/configure.host
@@ -48,6 +48,7 @@ hppa*-*-hpux10.20)	gdb_host=hpux1020 ;;
 hppa*64*-*-hpux11*)	gdb_host=hpux11w ;;
 hppa*-*-hpux11*)	gdb_host=hpux11 ;;
 hppa*-*-hpux*)		gdb_host=hppahpux ;;
+hppa*-*-linux*)		gdb_host=linux ;;
 
 i[34567]86-ncr-*)	gdb_host=ncr3000 ;;
 i[34567]86-*-dgux*)	gdb_host=i386v4 ;;
diff --git a/gdb/configure.tgt b/gdb/configure.tgt
index aee9c7dfd2e..646b2588f25 100644
--- a/gdb/configure.tgt
+++ b/gdb/configure.tgt
@@ -74,6 +74,7 @@ frv-*-*)		gdb_target=frv ;;
 hppa*64*-*-hpux11*)	gdb_target=hppa64 ;;
 hppa*-*-hpux*)		gdb_target=hppahpux ;;
 hppa*-*-hiux*)		gdb_target=hppahpux ;;
+hppa*-*-linux*)		gdb_target=linux ;;
 hppa*-*-*)		gdb_target=hppa ;;
 
 i[34567]86-ncr-*)	gdb_target=ncr3000 ;;
diff --git a/gdb/hppa-linux-nat.c b/gdb/hppa-linux-nat.c
new file mode 100644
index 00000000000..e633c06fc7b
--- /dev/null
+++ b/gdb/hppa-linux-nat.c
@@ -0,0 +1,277 @@
+/* Functions specific to running gdb native on HPPA running Linux.
+   Copyright 2004 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 "regcache.h"
+#include "gdb_string.h"
+
+#include <sys/procfs.h>
+#include <string.h>
+#include <asm/offsets.h>
+
+/* Prototypes for supply_gregset etc. */
+#include "gregset.h"
+
+/* These must match the order of the register names.
+
+   Some sort of lookup table is needed because the offsets associated
+   with the registers are all over the board.  */
+
+static const int u_offsets[] =
+  {
+    /* general registers */
+    -1,
+    PT_GR1,
+    PT_GR2,
+    PT_GR3,
+    PT_GR4,
+    PT_GR5,
+    PT_GR6,
+    PT_GR7,
+    PT_GR8,
+    PT_GR9,
+    PT_GR10,
+    PT_GR11,
+    PT_GR12,
+    PT_GR13,
+    PT_GR14,
+    PT_GR15,
+    PT_GR16,
+    PT_GR17,
+    PT_GR18,
+    PT_GR19,
+    PT_GR20,
+    PT_GR21,
+    PT_GR22,
+    PT_GR23,
+    PT_GR24,
+    PT_GR25,
+    PT_GR26,
+    PT_GR27,
+    PT_GR28,
+    PT_GR29,
+    PT_GR30,
+    PT_GR31,
+
+    PT_SAR,
+    PT_IAOQ0,
+    PT_IASQ0,
+    PT_IAOQ1,
+    PT_IASQ1,
+    -1, /* eiem */
+    PT_IIR,
+    PT_ISR,
+    PT_IOR,
+    PT_PSW,
+    -1, /* goto */
+
+    PT_SR4,
+    PT_SR0,
+    PT_SR1,
+    PT_SR2,
+    PT_SR3,
+    PT_SR5,
+    PT_SR6,
+    PT_SR7,
+
+    -1, /* cr0 */
+    -1, /* pid0 */
+    -1, /* pid1 */
+    -1, /* ccr */
+    -1, /* pid2 */
+    -1, /* pid3 */
+    -1, /* cr24 */
+    -1, /* cr25 */
+    -1, /* cr26 */
+    PT_CR27,
+    -1, /* cr28 */
+    -1, /* cr29 */
+    -1, /* cr30 */
+
+    /* Floating point regs.  */
+    PT_FR0,  PT_FR0 + 4,
+    PT_FR1,  PT_FR1 + 4,
+    PT_FR2,  PT_FR2 + 4,
+    PT_FR3,  PT_FR3 + 4,
+    PT_FR4,  PT_FR4 + 4,
+    PT_FR5,  PT_FR5 + 4,
+    PT_FR6,  PT_FR6 + 4,
+    PT_FR7,  PT_FR7 + 4,
+    PT_FR8,  PT_FR8 + 4,
+    PT_FR9,  PT_FR9 + 4,
+    PT_FR10, PT_FR10 + 4,
+    PT_FR11, PT_FR11 + 4,
+    PT_FR12, PT_FR12 + 4,
+    PT_FR13, PT_FR13 + 4,
+    PT_FR14, PT_FR14 + 4,
+    PT_FR15, PT_FR15 + 4,
+    PT_FR16, PT_FR16 + 4,
+    PT_FR17, PT_FR17 + 4,
+    PT_FR18, PT_FR18 + 4,
+    PT_FR19, PT_FR19 + 4,
+    PT_FR20, PT_FR20 + 4,
+    PT_FR21, PT_FR21 + 4,
+    PT_FR22, PT_FR22 + 4,
+    PT_FR23, PT_FR23 + 4,
+    PT_FR24, PT_FR24 + 4,
+    PT_FR25, PT_FR25 + 4,
+    PT_FR26, PT_FR26 + 4,
+    PT_FR27, PT_FR27 + 4,
+    PT_FR28, PT_FR28 + 4,
+    PT_FR29, PT_FR29 + 4,
+    PT_FR30, PT_FR30 + 4,
+    PT_FR31, PT_FR31 + 4,
+  };
+
+CORE_ADDR
+register_addr (int regno, CORE_ADDR blockend)
+{
+  CORE_ADDR addr;
+
+  if ((unsigned) regno >= NUM_REGS)
+    error ("Invalid register number %d.", regno);
+
+  if (u_offsets[regno] == -1)
+    addr = 0;
+  else
+    {
+      addr = (CORE_ADDR) u_offsets[regno];
+    }
+
+  return addr;
+}
+
+/*
+ * Registers saved in a coredump:
+ * gr0..gr31
+ * sr0..sr7
+ * iaoq0..iaoq1
+ * iasq0..iasq1
+ * sar, iir, isr, ior, ipsw
+ * cr0, cr24..cr31
+ * cr8,9,12,13
+ * cr10, cr15
+ */
+#define GR_REGNUM(_n)	(R0_REGNUM+_n)
+#define TR_REGNUM(_n)	(TR0_REGNUM+_n)
+static const int greg_map[] =
+  {
+    GR_REGNUM(0), GR_REGNUM(1), GR_REGNUM(2), GR_REGNUM(3),
+    GR_REGNUM(4), GR_REGNUM(5), GR_REGNUM(6), GR_REGNUM(7),
+    GR_REGNUM(8), GR_REGNUM(9), GR_REGNUM(10), GR_REGNUM(11),
+    GR_REGNUM(12), GR_REGNUM(13), GR_REGNUM(14), GR_REGNUM(15),
+    GR_REGNUM(16), GR_REGNUM(17), GR_REGNUM(18), GR_REGNUM(19),
+    GR_REGNUM(20), GR_REGNUM(21), GR_REGNUM(22), GR_REGNUM(23),
+    GR_REGNUM(24), GR_REGNUM(25), GR_REGNUM(26), GR_REGNUM(27),
+    GR_REGNUM(28), GR_REGNUM(29), GR_REGNUM(30), GR_REGNUM(31),
+
+    SR4_REGNUM+1, SR4_REGNUM+2, SR4_REGNUM+3, SR4_REGNUM+4,
+    SR4_REGNUM, SR4_REGNUM+5, SR4_REGNUM+6, SR4_REGNUM+7,
+
+    PCOQ_HEAD_REGNUM, PCOQ_TAIL_REGNUM,
+    PCSQ_HEAD_REGNUM, PCSQ_TAIL_REGNUM,
+
+    SAR_REGNUM, IIR_REGNUM, ISR_REGNUM, IOR_REGNUM,
+    IPSW_REGNUM, RCR_REGNUM,
+
+    TR_REGNUM(0), TR_REGNUM(1), TR_REGNUM(2), TR_REGNUM(3),
+    TR_REGNUM(4), TR_REGNUM(5), TR_REGNUM(6), TR_REGNUM(7),
+
+    PID0_REGNUM, PID1_REGNUM, PID2_REGNUM, PID3_REGNUM,
+    CCR_REGNUM, EIEM_REGNUM,
+  };
+
+void
+supply_gregset (gdb_gregset_t *gregsetp)
+{
+  int i;
+  greg_t *regp = (elf_greg_t *) gregsetp;
+
+  for (i = 0; i < sizeof (greg_map) / sizeof (greg_map[0]); i++, regp++)
+    {
+      int regno = greg_map[i];
+      int size = register_size (current_gdbarch, regno);
+      /* When running a 64 bit kernel, a greg_t may be larger than the
+	 actual register, so just pick off the LS bits of big-endian word.  */
+      supply_register (regno, ((char *) (regp + 1)) - size);
+    }
+}
+
+void
+fill_gregset (gdb_gregset_t *gregsetp, int regno)
+{
+  int i;
+  greg_t *regp = (greg_t *) gregsetp;
+
+  memset (gregsetp, 0, sizeof (*gregsetp));
+  for (i = 0; i < sizeof (greg_map) / sizeof (greg_map[0]); i++, regp++)
+    {
+      int regi = greg_map[i];
+
+      if (regno == -1 || regi == regno)
+	{
+	  int rawsize = register_size (current_gdbarch, regi);
+	  regcache_collect (regi, ((char *) (regp + 1)) - rawsize);
+	}
+    }
+}
+
+/*  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 (gdb_fpregset_t *fpregsetp)
+{
+  register int regi;
+  char *from;
+
+  for (regi = 0; regi <= 31; regi++)
+    {
+      from = (char *) &((*fpregsetp)[regi]);
+      supply_register (2*regi + HPPA_FP0_REGNUM, from);
+      supply_register (2*regi + HPPA_FP0_REGNUM + 1, from + 4);
+    }
+}
+
+/*  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 (gdb_fpregset_t *fpregsetp, int regno)
+{
+  int i;
+
+  for (i = 0; i < NUM_REGS; i++)
+   {
+    if (regno == -1 || regno == i)
+      {
+        /* Gross.  fpregset_t is double, registers[x] has single
+	   precision reg.  */
+        char *to = (char *) &((*fpregsetp)[(i - HPPA_FP0_REGNUM) / 2]);
+        if ((i - HPPA_FP0_REGNUM) & 1)
+	  to += 4;
+        regcache_collect (i, to);
+      }
+   }
+}
diff --git a/gdb/hppa-linux-tdep.c b/gdb/hppa-linux-tdep.c
new file mode 100644
index 00000000000..bdcb4a7455a
--- /dev/null
+++ b/gdb/hppa-linux-tdep.c
@@ -0,0 +1,499 @@
+/* Target-dependent code for Linux running on PA-RISC, for GDB.
+
+   Copyright 2004 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 "osabi.h"
+#include "target.h"
+#include "objfiles.h"
+#include "solib-svr4.h"
+#include "glibc-tdep.h"
+#include "frame-unwind.h"
+#include "trad-frame.h"
+#include "dwarf2-frame.h"
+#include "hppa-tdep.h"
+
+#if 0
+/* Convert DWARF register number REG to the appropriate register
+   number used by GDB.  */
+static int
+hppa_dwarf_reg_to_regnum (int reg)
+{
+  /* registers 0 - 31 are the same in both sets */
+  if (reg < 32)
+    return reg;
+
+  /* dwarf regs 32 to 85 are fpregs 4 - 31 */
+  if (reg >= 32 && reg <= 85)
+    return FP4_REGNUM + (reg - 32);
+
+  warning ("Unmapped DWARF Register #%d encountered\n", reg);
+  return -1;
+}
+#endif
+
+static void
+hppa_linux_target_write_pc (CORE_ADDR v, ptid_t ptid)
+{
+  /* Probably this should be done by the kernel, but it isn't.  */
+  write_register_pid (PCOQ_HEAD_REGNUM, v | 0x3, ptid);
+  write_register_pid (PCOQ_TAIL_REGNUM, (v + 4) | 0x3, ptid);
+}
+
+/* An instruction to match.  */
+struct insn_pattern
+{
+  unsigned int data;            /* See if it matches this....  */
+  unsigned int mask;            /* ... with this mask.  */
+};
+
+/* See bfd/elf32-hppa.c */
+static struct insn_pattern hppa_long_branch_stub[] = {
+  /* ldil LR'xxx,%r1 */
+  { 0x20200000, 0xffe00000 },
+  /* be,n RR'xxx(%sr4,%r1) */
+  { 0xe0202002, 0xffe02002 }, 
+  { 0, 0 }
+};
+
+static struct insn_pattern hppa_long_branch_pic_stub[] = {
+  /* b,l .+8, %r1 */
+  { 0xe8200000, 0xffe00000 },
+  /* addil LR'xxx - ($PIC_pcrel$0 - 4), %r1 */
+  { 0x28200000, 0xffe00000 },
+  /* be,n RR'xxxx - ($PIC_pcrel$0 - 8)(%sr4, %r1) */
+  { 0xe0202002, 0xffe02002 }, 
+  { 0, 0 }
+};
+
+static struct insn_pattern hppa_import_stub[] = {
+  /* addil LR'xxx, %dp */
+  { 0x2b600000, 0xffe00000 },
+  /* ldw RR'xxx(%r1), %r21 */
+  { 0x48350000, 0xffffb000 },
+  /* bv %r0(%r21) */
+  { 0xeaa0c000, 0xffffffff },
+  /* ldw RR'xxx+4(%r1), %r19 */
+  { 0x48330000, 0xffffb000 },
+  { 0, 0 }
+};
+
+static struct insn_pattern hppa_import_pic_stub[] = {
+  /* addil LR'xxx,%r19 */
+  { 0x2a600000, 0xffe00000 },
+  /* ldw RR'xxx(%r1),%r21 */
+  { 0x48350000, 0xffffb000 },
+  /* bv %r0(%r21) */
+  { 0xeaa0c000, 0xffffffff },
+  /* ldw RR'xxx+4(%r1),%r19 */
+  { 0x48330000, 0xffffb000 },
+  { 0, 0 },
+};
+
+static struct insn_pattern hppa_plt_stub[] = {
+  /* b,l 1b, %r20 - 1b is 3 insns before here */
+  { 0xea9f1fdd, 0xffffffff },
+  /* depi 0,31,2,%r20 */
+  { 0xd6801c1e, 0xffffffff },
+  { 0, 0 }
+};
+
+static struct insn_pattern hppa_sigtramp[] = {
+  /* ldi 0, %r25 or ldi 1, %r25 */
+  { 0x34190000, 0xfffffffd },
+  /* ldi __NR_rt_sigreturn, %r20 */
+  { 0x3414015a, 0xffffffff },
+  /* be,l 0x100(%sr2, %r0), %sr0, %r31 */
+  { 0xe4008200, 0xffffffff },
+  /* nop */
+  { 0x08000240, 0xffffffff },
+  { 0, 0 }
+};
+
+#define HPPA_MAX_INSN_PATTERN_LEN (4)
+
+/* Return non-zero if the instructions at PC match the series
+   described in PATTERN, or zero otherwise.  PATTERN is an array of
+   'struct insn_pattern' objects, terminated by an entry whose mask is
+   zero.
+
+   When the match is successful, fill INSN[i] with what PATTERN[i]
+   matched.  */
+static int
+insns_match_pattern (CORE_ADDR pc,
+                     struct insn_pattern *pattern,
+                     unsigned int *insn)
+{
+  int i;
+  CORE_ADDR npc = pc;
+
+  for (i = 0; pattern[i].mask; i++)
+    {
+      insn[i] = read_memory_unsigned_integer (npc, 4);
+      if ((insn[i] & pattern[i].mask) == pattern[i].data)
+        npc += 4;
+      else
+        return 0;
+    }
+  return 1;
+}
+
+static int
+hppa_linux_in_dyncall (CORE_ADDR pc)
+{
+  static CORE_ADDR dyncall = 0;
+
+  /* FIXME: if we switch exec files, dyncall should be reinitialized */
+  if (!dyncall)
+    {
+      struct minimal_symbol *minsym;
+
+      minsym = lookup_minimal_symbol ("$$dyncall", NULL, NULL);
+      if (minsym)
+	dyncall = SYMBOL_VALUE_ADDRESS (minsym);
+      else
+	dyncall = -1;
+    }
+
+  return pc == dyncall;
+}
+
+/* There are several kinds of "trampolines" that we need to deal with:
+   - long branch stubs: these are inserted by the linker when a branch
+     target is too far away for a branch insn to reach
+   - plt stubs: these should go into the .plt section, so are easy to find
+   - import stubs: used to call from object to shared lib or shared lib to 
+     shared lib; these go in regular text sections.  In fact the linker tries
+     to put them throughout the code because branches have limited reachability.
+     We use the same mechanism as ppc64 to recognize the stub insn patterns.
+   - $$dyncall: similar to hpux, hppa-linux uses $$dyncall for indirect function
+     calls. $$dyncall is exported by libgcc.a  */
+static int
+hppa_linux_in_solib_call_trampoline (CORE_ADDR pc, char *name)
+{
+  unsigned int insn[HPPA_MAX_INSN_PATTERN_LEN];
+  int r;
+
+  r = in_plt_section (pc, name)
+      || hppa_linux_in_dyncall (pc)
+      || insns_match_pattern (pc, hppa_import_stub, insn)
+      || insns_match_pattern (pc, hppa_import_pic_stub, insn)
+      || insns_match_pattern (pc, hppa_long_branch_stub, insn)
+      || insns_match_pattern (pc, hppa_long_branch_pic_stub, insn);
+
+  return r;
+}
+
+static CORE_ADDR
+hppa_linux_skip_trampoline_code (CORE_ADDR pc)
+{
+  unsigned int insn[HPPA_MAX_INSN_PATTERN_LEN];
+  int dp_rel, pic_rel;
+
+  /* dyncall handles both PLABELs and direct addresses */
+  if (hppa_linux_in_dyncall (pc))
+    {
+      pc = (CORE_ADDR) read_register (22);
+
+      /* PLABELs have bit 30 set; if it's a PLABEL, then dereference it */
+      if (pc & 0x2)
+	pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, TARGET_PTR_BIT / 8);
+
+      return pc;
+    }
+
+  dp_rel = pic_rel = 0;
+  if ((dp_rel = insns_match_pattern (pc, hppa_import_stub, insn))
+      || (pic_rel = insns_match_pattern (pc, hppa_import_pic_stub, insn)))
+    {
+      /* Extract the target address from the addil/ldw sequence.  */
+      pc = hppa_extract_21 (insn[0]) + hppa_extract_14 (insn[1]);
+
+      if (dp_rel)
+        pc += (CORE_ADDR) read_register (27);
+      else
+        pc += (CORE_ADDR) read_register (19);
+
+      /* fallthrough */
+    }
+
+  if (in_plt_section (pc, NULL))
+    {
+      pc = (CORE_ADDR) read_memory_integer (pc, TARGET_PTR_BIT / 8);
+
+      /* if the plt slot has not yet been resolved, the target will
+         be the plt stub */
+      if (in_plt_section (pc, NULL))
+	{
+	  /* Sanity check: are we pointing to the plt stub? */
+  	  if (insns_match_pattern (pc, hppa_plt_stub, insn))
+	    {
+	      /* this should point to the fixup routine */
+      	      pc = (CORE_ADDR) read_memory_integer (pc + 8, TARGET_PTR_BIT / 8);
+	    }
+	  else
+	    {
+	      error ("Cannot resolve plt stub at 0x%s\n",
+		     paddr_nz (pc));
+	      pc = 0;
+	    }
+	}
+    }
+
+  return pc;
+}
+
+/* Signal frames.  */
+
+/* (This is derived from MD_FALLBACK_FRAME_STATE_FOR in gcc.)
+ 
+   Unfortunately, because of various bugs and changes to the kernel,
+   we have several cases to deal with.
+
+   In 2.4, the signal trampoline is 4 bytes, and pc should point directly at 
+   the beginning of the trampoline and struct rt_sigframe.
+
+   In <= 2.6.5-rc2-pa3, the signal trampoline is 9 bytes, and pc points at
+   the 4th word in the trampoline structure.  This is wrong, it should point 
+   at the 5th word.  This is fixed in 2.6.5-rc2-pa4.
+
+   To detect these cases, we first take pc, align it to 64-bytes
+   to get the beginning of the signal frame, and then check offsets 0, 4
+   and 5 to see if we found the beginning of the trampoline.  This will
+   tell us how to locate the sigcontext structure.
+
+   Note that with a 2.4 64-bit kernel, the signal context is not properly
+   passed back to userspace so the unwind will not work correctly.  */
+static CORE_ADDR
+hppa_linux_sigtramp_find_sigcontext (CORE_ADDR sp)
+{
+  unsigned int dummy[HPPA_MAX_INSN_PATTERN_LEN];
+  int offs = 0;
+  int try;
+  /* offsets to try to find the trampoline */
+  static int pcoffs[] = { 0, 4*4, 5*4 };
+  /* offsets to the rt_sigframe structure */
+  static int sfoffs[] = { 4*4, 10*4, 10*4 };
+
+  /* rt_sigreturn trampoline:
+     3419000x ldi 0, %r25 or ldi 1, %r25   (x = 0 or 2)
+     3414015a ldi __NR_rt_sigreturn, %r20 
+     e4008200 be,l 0x100(%sr2, %r0), %sr0, %r31
+     08000240 nop  */
+
+  for (try = 0; try < ARRAY_SIZE (pcoffs); try++)
+    {
+      if (insns_match_pattern (sp + pcoffs[try], hppa_sigtramp, dummy))
+	{
+          offs = sfoffs[try];
+	  break;
+	}
+    }
+
+  if (offs == 0)
+    return 0;
+
+  /* sp + sfoffs[try] points to a struct rt_sigframe, which contains
+     a struct siginfo and a struct ucontext.  struct ucontext contains
+     a struct sigcontext. Return an offset to this sigcontext here.  Too 
+     bad we cannot include system specific headers :-(.  
+     sizeof(struct siginfo) == 128
+     offsetof(struct ucontext, uc_mcontext) == 24.  */
+  return sp + sfoffs[try] + 128 + 24;
+}
+
+struct hppa_linux_sigtramp_unwind_cache
+{
+  CORE_ADDR base;
+  struct trad_frame_saved_reg *saved_regs;
+};
+
+static struct hppa_linux_sigtramp_unwind_cache *
+hppa_linux_sigtramp_frame_unwind_cache (struct frame_info *next_frame,
+					void **this_cache)
+{
+  struct gdbarch *gdbarch = get_frame_arch (next_frame);
+  struct hppa_linux_sigtramp_unwind_cache *info;
+  CORE_ADDR sp, pc, scptr;
+  int i;
+
+  if (*this_cache)
+    return *this_cache;
+
+  info = FRAME_OBSTACK_ZALLOC (struct hppa_linux_sigtramp_unwind_cache);
+  *this_cache = info;
+  info->saved_regs = trad_frame_alloc_saved_regs (next_frame);
+
+  pc = frame_pc_unwind (next_frame);
+  sp = (pc & ~63);
+  scptr = hppa_linux_sigtramp_find_sigcontext (sp);
+
+  /* structure of struct sigcontext:
+   
+     struct sigcontext {
+	unsigned long sc_flags;
+	unsigned long sc_gr[32]; 
+	unsigned long long sc_fr[32];
+	unsigned long sc_iasq[2];
+	unsigned long sc_iaoq[2];
+	unsigned long sc_sar;           */
+
+  /* Skip sc_flags.  */
+  scptr += 4;
+
+  /* GR[0] is the psw, we don't restore that.  */
+  scptr += 4;
+
+  /* General registers.  */
+  for (i = 1; i < 32; i++)
+    {
+      info->saved_regs[R0_REGNUM + i].addr = scptr;
+      scptr += 4;
+    }
+
+  /* Pad.  */
+  scptr += 4;
+
+  /* FP regs; FP0-3 are not restored.  */
+  scptr += (8 * 4);
+
+  for (i = 4; i < 32; i++)
+    {
+      info->saved_regs[HPPA_FP0_REGNUM + (i * 2)].addr = scptr;
+      scptr += 4;
+      info->saved_regs[HPPA_FP0_REGNUM + (i * 2) + 1].addr = scptr;
+      scptr += 4;
+    }
+
+  /* IASQ/IAOQ. */
+  info->saved_regs[PCSQ_HEAD_REGNUM].addr = scptr;
+  scptr += 4;
+  info->saved_regs[PCSQ_TAIL_REGNUM].addr = scptr;
+  scptr += 4;
+
+  info->saved_regs[PCOQ_HEAD_REGNUM].addr = scptr;
+  scptr += 4;
+  info->saved_regs[PCOQ_TAIL_REGNUM].addr = scptr;
+  scptr += 4;
+
+  info->base = read_memory_unsigned_integer (
+		  info->saved_regs[HPPA_SP_REGNUM].addr, 4);
+
+  return info;
+}
+
+static void
+hppa_linux_sigtramp_frame_this_id (struct frame_info *next_frame,
+				   void **this_prologue_cache,
+				   struct frame_id *this_id)
+{
+  struct hppa_linux_sigtramp_unwind_cache *info
+    = hppa_linux_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache);
+  *this_id = frame_id_build (info->base, frame_pc_unwind (next_frame));
+}
+
+static void
+hppa_linux_sigtramp_frame_prev_register (struct frame_info *next_frame,
+					 void **this_prologue_cache,
+					 int regnum, int *optimizedp,
+					 enum lval_type *lvalp, 
+					 CORE_ADDR *addrp,
+					 int *realnump, void *bufferp)
+{
+  struct hppa_linux_sigtramp_unwind_cache *info
+    = hppa_linux_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache);
+  int pcoqt = (regnum == PCOQ_TAIL_REGNUM);
+
+  if (pcoqt)
+    regnum = PCOQ_HEAD_REGNUM;
+
+  trad_frame_prev_register (next_frame, info->saved_regs, regnum,
+                            optimizedp, lvalp, addrp, realnump, bufferp);
+
+  if (pcoqt)
+    store_unsigned_integer (bufferp, 4, 
+		      	    extract_unsigned_integer (bufferp, 4) + 4);
+}
+
+static const struct frame_unwind hppa_linux_sigtramp_frame_unwind = {
+  SIGTRAMP_FRAME,
+  hppa_linux_sigtramp_frame_this_id,
+  hppa_linux_sigtramp_frame_prev_register
+};
+
+/* hppa-linux always uses "new-style" rt-signals.  The signal handler's return
+   address should point to a signal trampoline on the stack.  The signal
+   trampoline is embedded in a rt_sigframe structure that is aligned on
+   the stack.  We take advantage of the fact that sp must be 64-byte aligned,
+   and the trampoline is small, so by rounding down the trampoline address
+   we can find the beginning of the struct rt_sigframe.  */
+static const struct frame_unwind *
+hppa_linux_sigtramp_unwind_sniffer (struct frame_info *next_frame)
+{
+  CORE_ADDR pc = frame_pc_unwind (next_frame);
+  CORE_ADDR sp = (pc & ~63);
+
+  if (hppa_linux_sigtramp_find_sigcontext (sp))
+    return &hppa_linux_sigtramp_frame_unwind;
+
+  return NULL;
+}
+
+/* Forward declarations.  */
+extern initialize_file_ftype _initialize_hppa_linux_tdep;
+
+static void
+hppa_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+  /* Linux is always ELF.  */
+  tdep->is_elf = 1;
+
+  set_gdbarch_write_pc (gdbarch, hppa_linux_target_write_pc);
+
+  frame_unwind_append_sniffer (gdbarch, hppa_linux_sigtramp_unwind_sniffer);
+
+  /* GNU/Linux uses SVR4-style shared libraries.  */
+  set_solib_svr4_fetch_link_map_offsets
+    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+
+  set_gdbarch_in_solib_call_trampoline
+        (gdbarch, hppa_linux_in_solib_call_trampoline);
+  set_gdbarch_skip_trampoline_code
+	(gdbarch, hppa_linux_skip_trampoline_code);
+
+  /* GNU/Linux uses the dynamic linker included in the GNU C Library.  */
+  set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
+
+#if 0
+  /* Dwarf-2 unwinding support.  Not yet working.  */
+  set_gdbarch_dwarf_reg_to_regnum (gdbarch, hppa_dwarf_reg_to_regnum);
+  set_gdbarch_dwarf2_reg_to_regnum (gdbarch, hppa_dwarf_reg_to_regnum);
+  frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer);
+  frame_base_append_sniffer (gdbarch, dwarf2_frame_base_sniffer);
+#endif
+}
+
+void
+_initialize_hppa_linux_tdep (void)
+{
+  gdbarch_register_osabi (bfd_arch_hppa, 0, GDB_OSABI_LINUX, hppa_linux_init_abi);
+}
diff --git a/gdb/hppa-tdep.c b/gdb/hppa-tdep.c
index 5e84782ff03..a366717c1ff 100644
--- a/gdb/hppa-tdep.c
+++ b/gdb/hppa-tdep.c
@@ -2332,6 +2332,7 @@ hppa_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   set_gdbarch_sp_regnum (gdbarch, HPPA_SP_REGNUM);
   set_gdbarch_fp0_regnum (gdbarch, HPPA_FP0_REGNUM);
   set_gdbarch_cannot_store_register (gdbarch, hppa_cannot_store_register);
+  set_gdbarch_cannot_fetch_register (gdbarch, hppa_cannot_store_register);
   set_gdbarch_addr_bits_remove (gdbarch, hppa_smash_text_address);
   set_gdbarch_smash_text_address (gdbarch, hppa_smash_text_address);
   set_gdbarch_believe_pcc_promotion (gdbarch, 1);
@@ -2384,14 +2385,14 @@ hppa_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   set_gdbarch_unwind_dummy_id (gdbarch, hppa_unwind_dummy_id);
   set_gdbarch_unwind_pc (gdbarch, hppa_unwind_pc);
 
+  /* Hook in ABI-specific overrides, if they have been registered.  */
+  gdbarch_init_osabi (info, gdbarch);
+
   /* Hook in the default unwinders.  */
   frame_unwind_append_sniffer (gdbarch, hppa_stub_unwind_sniffer);
   frame_unwind_append_sniffer (gdbarch, hppa_frame_unwind_sniffer);
   frame_base_append_sniffer (gdbarch, hppa_frame_base_sniffer);
 
-  /* Hook in ABI-specific overrides, if they have been registered.  */
-  gdbarch_init_osabi (info, gdbarch);
-
   return gdbarch;
 }