Hurd/PowerPC port contributed by Peter Bruin <pjbruin@dds.nl>.

	* NEWS: Mention it.
	* sysdeps/mach/hurd/powerpc/exc2signal.c: New file.
	* sysdeps/mach/hurd/powerpc/init-first.c: New file.
	* sysdeps/mach/hurd/powerpc/intr-msg.h: New file.
	* sysdeps/mach/hurd/powerpc/longjmp-ts.c: New file.
	* sysdeps/mach/hurd/powerpc/register-dump.h: New file.
	* sysdeps/mach/hurd/powerpc/sigreturn.c: New file.
	* sysdeps/mach/hurd/powerpc/static-start.S: New file.
	* sysdeps/mach/hurd/powerpc/trampoline.c: New file.
	* sysdeps/mach/hurd/powerpc/bits/sigcontext.h: New file.
	* sysdeps/mach/hurd/powerpc/Dist: New file.

10 files changed, 1260 insertions, 0 deletions

diff --git a/sysdeps/mach/hurd/powerpc/Dist b/sysdeps/mach/hurd/powerpc/Dist
new file mode 100644
index 0000000000..c58180257e
--- /dev/null
+++ b/sysdeps/mach/hurd/powerpc/Dist
@@ -0,0 +1 @@
+static-start.S
diff --git a/sysdeps/mach/hurd/powerpc/bits/sigcontext.h b/sysdeps/mach/hurd/powerpc/bits/sigcontext.h
new file mode 100644
index 0000000000..6f14ec5c31
--- /dev/null
+++ b/sysdeps/mach/hurd/powerpc/bits/sigcontext.h
@@ -0,0 +1,76 @@
+/* Machine-dependent signal context structure for GNU Hurd.  PowerPC version.
+   Copyright (C) 1991, 1992, 1994, 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef _SIGNAL_H
+# error "Never use <bits/sigcontext.h> directly; include <signal.h> instead."
+#endif
+
+/* Signal handlers are actually called:
+   void handler (int sig, int code, struct sigcontext *scp);  */
+
+/* State of this thread when the signal was taken.  */
+struct sigcontext
+  {
+    /* These first members are machine-independent.  */
+
+    int sc_onstack;		/* Nonzero if running on sigstack.  */
+    __sigset_t sc_mask;		/* Blocked signals to restore.  */
+
+    /* MiG reply port this thread is using.  */
+    unsigned int sc_reply_port;
+
+    /* Port this thread is doing an interruptible RPC on.  */
+    unsigned int sc_intr_port;
+
+    /* Error code associated with this signal (interpreted as `error_t').  */
+    int sc_error;
+
+    /* All following members are machine-dependent.  The rest of this
+       structure is written to be laid out identically to:
+       {
+	 struct ppc_thread_state basic;
+	 struct ppc_exc_state exc;
+	 struct ppc_float_state fpu;
+       }
+       trampoline.c knows this, so it must be changed if this changes.  */
+
+#define sc_ppc_thread_state sc_srr0 /* Beginning of correspondence.  */
+#define sc_pc sc_srr0 /* For sysdeps/generic/profil-counter.h.  */
+    unsigned int sc_srr0;
+    unsigned int sc_srr1;
+    unsigned int sc_gprs[32];
+    unsigned int sc_cr;
+    unsigned int sc_xer;
+    unsigned int sc_lr;
+    unsigned int sc_ctr;
+    unsigned int sc_mq;
+    unsigned int sc_ts_pad;
+
+#define sc_ppc_exc_state sc_dar
+    unsigned int sc_dar;
+    unsigned int sc_dsisr;
+    unsigned int sc_exception;
+    unsigned int sc_es_pad0;
+    unsigned int sc_es_pad1[4];
+
+#define sc_ppc_float_state sc_fprs[0]
+    double sc_fprs[32];
+    unsigned int sc_fpscr_pad;
+    unsigned int sc_fpscr;
+  };
diff --git a/sysdeps/mach/hurd/powerpc/exc2signal.c b/sysdeps/mach/hurd/powerpc/exc2signal.c
new file mode 100644
index 0000000000..7cea85daa0
--- /dev/null
+++ b/sysdeps/mach/hurd/powerpc/exc2signal.c
@@ -0,0 +1,74 @@
+/* Translate Mach exception codes into signal numbers.  PowerPC version.
+   Copyright (C) 1991,92,94,96,97,2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <hurd.h>
+#include <hurd/signal.h>
+#include <mach/exception.h>
+
+/* Translate the Mach exception codes, as received in an `exception_raise' RPC,
+   into a signal number and signal subcode.  */
+
+void
+_hurd_exception2signal (struct hurd_signal_detail *detail, int *signo)
+{
+  detail->error = 0;
+
+  switch (detail->exc)
+    {
+    default:
+      *signo = SIGIOT;
+      detail->code = detail->exc;
+      break;
+
+    case EXC_BAD_ACCESS:
+      if (detail->exc_code == KERN_PROTECTION_FAILURE)
+	*signo = SIGSEGV;
+      else
+	*signo = SIGBUS;
+      detail->code = detail->exc_subcode;
+      detail->error = detail->exc_code;
+      break;
+
+      /* XXX there has got to be something more here */
+
+    case EXC_BAD_INSTRUCTION:
+      *signo = SIGILL;
+      detail->code = 0;
+      break;
+
+    case EXC_ARITHMETIC:
+      *signo = SIGFPE;
+      detail->code = 0;
+      break;
+
+    case EXC_EMULATION:
+      *signo = SIGEMT;
+      detail->code = 0;
+      break;
+
+    case EXC_SOFTWARE:
+      *signo = SIGEMT;
+      detail->code = 0;
+      break;
+
+    case EXC_BREAKPOINT:
+      *signo = SIGTRAP;
+      detail->code = 0;
+    }
+}
diff --git a/sysdeps/mach/hurd/powerpc/init-first.c b/sysdeps/mach/hurd/powerpc/init-first.c
new file mode 100644
index 0000000000..25f5c53716
--- /dev/null
+++ b/sysdeps/mach/hurd/powerpc/init-first.c
@@ -0,0 +1,333 @@
+/* Initialization code run first thing by the ELF startup code.  PowerPC/Hurd.
+   Copyright (C) 1995,96,97,98,99,2000,01 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <assert.h>
+#include <hurd.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <sysdep.h>
+#include <set-hooks.h>
+#include "hurdstartup.h"
+#include "hurdmalloc.h"		/* XXX */
+
+extern void __mach_init (void);
+extern void __libc_init (int, char **, char **);
+#ifdef USE_NONOPTION_FLAGS
+extern void __getopt_clean_environment (char **);
+#endif
+extern void __libc_global_ctors (void);
+
+unsigned int __hurd_threadvar_max;
+unsigned long int __hurd_threadvar_stack_offset;
+unsigned long int __hurd_threadvar_stack_mask;
+
+#ifndef SHARED
+int __libc_enable_secure;
+#endif
+int __libc_multiple_libcs = 1;
+
+extern int __libc_argc;
+extern char **__libc_argv;
+extern char **_dl_argv;
+
+void *(*_cthread_init_routine) (void); /* Returns new SP to use.  */
+void (*_cthread_exit_routine) (int status) __attribute__ ((__noreturn__));
+
+#ifndef SHARED
+static unsigned int return_address;  /* Make init1 return to _start.  */
+#endif
+
+/* Things that want to be run before _hurd_init or much anything else.
+   Importantly, these are called before anything tries to use malloc.  */
+DEFINE_HOOK (_hurd_preinit_hook, (void));
+
+
+/* We call this once the Hurd magic is all set up and we are ready to be a
+   Posixoid program.  This does the same things the generic version does.  */
+static void internal_function
+posixland_init (int argc, char **argv, char **envp)
+{
+  asm ("li 3,0xbb; .long 0");
+  __libc_argc = argc;
+  __libc_argv = argv;
+  __environ = envp;
+
+  __libc_init (argc, argv, envp);
+
+#ifdef USE_NONOPTION_FLAGS
+  /* This is a hack to make the special getopt in GNU libc working.  */
+  __getopt_clean_environment (__environ);
+#endif
+
+#ifdef SHARED
+  __libc_global_ctors ();
+#endif
+}
+
+
+static void
+init1 (int *data)
+{
+  int argc = *data;
+  char **argv = (char **) &data[1];
+  char **envp = &argv[argc + 1];
+  struct hurd_startup_data *d;
+
+  while (*envp)
+    ++envp;
+  d = (void *) ++envp;
+
+  /* If we are the bootstrap task started by the kernel,
+     then after the environment pointers there is no Hurd
+     data block; the argument strings start there.  */
+  /* OSF Mach starts the bootstrap task with argc == 0.
+     XXX This fails if a non-bootstrap task gets started
+     with argc == 0.  */
+  if (argc && (void *) d != argv[0])
+    {
+      _hurd_init_dtable = d->dtable;
+      _hurd_init_dtablesize = d->dtablesize;
+
+#if 0  /* We can't free the old stack because it contains the argument strings.  */
+      {
+	/* Check if the stack we are now on is different from
+	   the one described by _hurd_stack_{base,size}.  */
+
+	char dummy;
+	const vm_address_t newsp = (vm_address_t) &dummy;
+
+	if (d->stack_size != 0 && (newsp < d->stack_base ||
+				   newsp - d->stack_base > d->stack_size))
+	  /* The new stack pointer does not intersect with the
+	     stack the exec server set up for us, so free that stack.  */
+	  __vm_deallocate (__mach_task_self (), d->stack_base, d->stack_size);
+      }
+#endif
+    }
+
+  if (argc && (void *) d != argv[0] && (d->portarray || d->intarray))
+    /* Initialize library data structures, start signal processing, etc.  */
+    _hurd_init (d->flags, argv,
+		d->portarray, d->portarraysize,
+		d->intarray, d->intarraysize);
+
+#ifndef SHARED
+  __libc_enable_secure = d->flags & EXEC_SECURE;
+#endif
+}
+
+
+static inline void
+init (int *data)
+{
+  int argc = *data;
+  char **argv = (void *) (data + 1);
+  char **envp = &argv[argc + 1];
+  struct hurd_startup_data *d;
+  unsigned long int threadvars[_HURD_THREADVAR_MAX];
+
+  /* Provide temporary storage for thread-specific variables on the startup
+     stack so the cthreads initialization code can use them for malloc et al,
+     or so we can use malloc below for the real threadvars array.  */
+  memset (threadvars, 0, sizeof threadvars);
+  __hurd_threadvar_stack_offset = (unsigned long int) threadvars;
+
+  while (*envp)
+    ++envp;
+  d = (void *) ++envp;
+
+  /* The user might have defined a value for this, to get more variables.
+     Otherwise it will be zero on startup.  We must make sure it is set
+     properly before before cthreads initialization, so cthreads can know
+     how much space to leave for thread variables.  */
+  if (__hurd_threadvar_max < _HURD_THREADVAR_MAX)
+    __hurd_threadvar_max = _HURD_THREADVAR_MAX;
+
+
+  /* After possibly switching stacks, call `init1' (above) with the user
+     code as the return address, and the argument data immediately above
+     that on the stack.  */
+
+  if (_cthread_init_routine)
+    {
+      /* Initialize cthreads, which will allocate us a new stack to run on.  */
+      void *newsp = (*_cthread_init_routine) ();
+      struct hurd_startup_data *od;
+#ifdef SHARED
+      void *oldsp;
+      unsigned int i, data_offset;
+#endif
+
+      /* Copy per-thread variables from that temporary
+	 area onto the new cthread stack.  */
+      memcpy (__hurd_threadvar_location_from_sp (0, newsp),
+	      threadvars, sizeof threadvars);
+
+      /* Copy the argdata from the old stack to the new one.  */
+      newsp = memcpy (newsp - ((char *) &d[1] - (char *) data), data,
+		      (char *) d - (char *) data);
+
+#ifdef SHARED
+      /* And readjust the dynamic linker's idea of where the argument
+         vector lives.  */
+      assert (_dl_argv == argv);
+      _dl_argv = (void *) ((int *) newsp + 1);
+#endif
+
+      /* Set up the Hurd startup data block immediately following
+	 the argument and environment pointers on the new stack.  */
+      od = (newsp + ((char *) d - (char *) data));
+      if (!argc || (void *) argv[0] == d)
+	/* We were started up by the kernel with arguments on the stack.
+	   There is no Hurd startup data, so zero the block.  */
+	memset (od, 0, sizeof *od);
+      else
+	/* Copy the Hurd startup data block to the new stack.  */
+	*od = *d;
+
+#ifndef SHARED
+      asm ("mtlr %0; mr 1,%1; li 0,0; mr 3,%1; stwu 0,-16(1); b init1"
+	   : : "r" (return_address), "r" (newsp));
+      (void) init1;  /* To avoid `defined but not used' warning.  */
+      /* NOTREACHED */
+#else
+      /* Copy the rest of the stack.  Don't call a function to do that,
+	 because that will alter the current stack.  */
+      asm ("mr %0,1" : "=r" (oldsp));
+      data_offset = (unsigned int) data - (unsigned int) oldsp;
+      newsp -= data_offset;
+      for (i = 0; i < data_offset / 4; i++)
+        ((unsigned int *)newsp)[i] = ((unsigned int *)oldsp)[i];
+
+      /* Relocate stack frames.  */
+      {
+	unsigned int *oldframe0 = (unsigned int *)oldsp;
+	unsigned int *oldframe1 = *(unsigned int **)oldframe0;
+	unsigned int *oldframe2 = *(unsigned int **)oldframe1;
+	unsigned int *newframe0 = (unsigned int *)newsp;
+	unsigned int *newframe1 = newframe0 + (unsigned int)(oldframe1 - oldframe0);
+	unsigned int *newframe2 = newframe1 + (unsigned int)(oldframe2 - oldframe1);
+	*(unsigned int **)newframe0 = newframe1;
+	*(unsigned int **)newframe1 = newframe2;
+      }
+
+      asm ("mr 1,%0; mr 31,%0" : : "r" (newsp));  /* XXX */
+      init1 (newsp + data_offset);
+#endif
+    }
+  else
+    {
+      /* We are not using cthreads, so we will have just a single allocated
+	 area for the per-thread variables of the main user thread.  */
+      unsigned long int *array;
+      unsigned int i;
+
+      array = malloc (__hurd_threadvar_max * sizeof (unsigned long int));
+      if (array == NULL)
+	__libc_fatal ("Can't allocate single-threaded thread variables.");
+
+      /* Copy per-thread variables from the temporary array into the
+	 newly malloc'd space.  */
+      memcpy (array, threadvars, sizeof threadvars);
+      __hurd_threadvar_stack_offset = (unsigned long int) array;
+      for (i = _HURD_THREADVAR_MAX; i < __hurd_threadvar_max; ++i)
+	array[i] = 0;
+
+#ifndef SHARED
+      asm ("mr 3,%0; mtlr %1; addi 1,3,-16; b init1"
+	   : : "r" (data), "r" (return_address));
+      /* NOTREACHED */
+#else
+      init1 (data);
+#endif
+    }
+}
+
+
+/* Do the first essential initializations that must precede all else.  */
+static inline void
+first_init (void)
+{
+  /* Initialize data structures so we can do RPCs.  */
+  __mach_init ();
+
+  RUN_HOOK (_hurd_preinit_hook, ());
+}
+
+#ifdef SHARED
+/* This function is called specially by the dynamic linker to do early
+   initialization of the shared C library before normal initializers
+   expecting a Posixoid environment can run.  It gets called with the
+   stack set up just as the user will see it, so it can switch stacks.  */
+
+void
+_dl_init_first (int argc, ...)
+{
+  asm ("li 3,0xaa; .long 0");
+  first_init ();
+
+  init (&argc);
+}
+#endif
+
+
+#ifdef SHARED
+/* The regular posixland initialization is what goes into libc's
+   normal initializer.  */
+/* NOTE!  The linker notices the magical name `_init' and sets the DT_INIT
+   pointer in the dynamic section based solely on that.  It is convention
+   for this function to be in the `.init' section, but the symbol name is
+   the only thing that really matters!!  */
+strong_alias (posixland_init, _init);
+
+
+void
+__libc_init_first (int argc, char **argv, char **envp)
+{
+  /* Everything was done in the shared library initializer, _init.  */
+}
+#else
+strong_alias (posixland_init, __libc_init_first);
+
+
+void
+_hurd_stack_setup (int *data)
+{
+  register unsigned int address;
+  asm ("mflr %0" : "=r" (address));
+  return_address = address;
+
+  first_init ();
+
+  _hurd_startup ((void **) data, &init);
+}
+#endif
+
+
+/* This function is defined here so that if this file ever gets into
+   ld.so we will get a link error.  Having this file silently included
+   in ld.so causes disaster, because the _init definition above will
+   cause ld.so to gain an init function, which is not a cool thing. */
+
+void
+_dl_start (void)
+{
+  abort ();
+}
diff --git a/sysdeps/mach/hurd/powerpc/intr-msg.h b/sysdeps/mach/hurd/powerpc/intr-msg.h
new file mode 100644
index 0000000000..244d7e67d9
--- /dev/null
+++ b/sysdeps/mach/hurd/powerpc/intr-msg.h
@@ -0,0 +1,99 @@
+/* Machine-dependent details of interruptible RPC messaging.  PowerPC version.
+   Copyright (C) 1995,96,97,99,2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#define INTR_MSG_TRAP(msg, option, send_size, rcv_size, rcv_name, timeout, notify) \
+({									\
+  error_t err;								\
+  asm (".globl _hurd_intr_rpc_msg_do_trap\n"				\
+       ".globl _hurd_intr_rpc_msg_in_trap\n"				\
+       "				mr 3, %1\n"			\
+       "				mr 4, %2\n"			\
+       "				mr 5, %3\n"			\
+       "				mr 6, %4\n"			\
+       "				mr 7, %5\n"			\
+       "				mr 8, %6\n"			\
+       "				mr 9, %7\n"			\
+       "				li 0, -25\n"			\
+       "_hurd_intr_rpc_msg_do_trap:	sc\n"				\
+       "_hurd_intr_rpc_msg_in_trap:	mr 3, %0\n"			\
+       : "=r" (err)							\
+       : "r" (msg), "r" (option), "r" (send_size), "r" (rcv_size),	\
+	 "r" (rcv_name), "r" (timeout), "r" (notify)			\
+       : "0", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12");	\
+  err;									\
+})
+
+static void inline
+INTR_MSG_BACK_OUT (struct ppc_thread_state *state)
+{
+  return;
+}
+
+#include "hurdfault.h"
+
+/* This cannot be an inline function because it calls setjmp.  */
+#define SYSCALL_EXAMINE(state, callno)					    \
+({									    \
+  u_int32_t *p = (void *) ((state)->srr0 - 4);				    \
+  int result;								    \
+  _hurdsig_catch_memory_fault (p) ? 0 :					    \
+  ({									    \
+    if (result = (*p == 0x44000002))					    \
+      /* The PC is just after an `sc' instruction.			    \
+         This is a system call in progress; %r0 holds the call number.  */  \
+      *(callno) = (state)->r0;						    \
+    _hurdsig_end_catch_fault ();					    \
+    result;								    \
+  });									    \
+})
+
+struct mach_msg_trap_args
+  {
+    /* This is the order of arguments to mach_msg_trap.  */
+    mach_msg_header_t *msg;
+    mach_msg_option_t option;
+    mach_msg_size_t send_size;
+    mach_msg_size_t rcv_size;
+    mach_port_t rcv_name;
+    mach_msg_timeout_t timeout;
+    mach_port_t notify;
+  };
+
+/* This cannot be an inline function because it calls setjmp.  */
+#define MSG_EXAMINE(state, msgid, rcv_name, send_name, option, timeout)   \
+({									  \
+  mach_msg_header_t *msg = (mach_msg_header_t *) (state)->r3;		  \
+  *(option) = (mach_msg_option_t) (state)->r4;				  \
+  *(rcv_name) = (mach_port_t) (state)->r7;				  \
+  *(timeout) = (mach_msg_timeout_t) (state)->r8;			  \
+  (msg == 0) ?								  \
+    ({									  \
+      *(send_name) = MACH_PORT_NULL;					  \
+      *(msgid) = 0;							  \
+      0;								  \
+    }) :								  \
+    (_hurdsig_catch_memory_fault (msg) ? -1 :				  \
+	({								  \
+	  *(send_name) = msg->msgh_remote_port;				  \
+	  *(msgid) = msg->msgh_id;					  \
+	  _hurdsig_end_catch_fault ();					  \
+	  0;								  \
+	})								  \
+    );									  \
+})									  \
diff --git a/sysdeps/mach/hurd/powerpc/longjmp-ts.c b/sysdeps/mach/hurd/powerpc/longjmp-ts.c
new file mode 100644
index 0000000000..4a59f16aa8
--- /dev/null
+++ b/sysdeps/mach/hurd/powerpc/longjmp-ts.c
@@ -0,0 +1,56 @@
+/* Perform a `longjmp' on a Mach thread_state.  PowerPC version.
+   Copyright (C) 1991,94,95,97,2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <hurd/signal.h>
+#include <setjmp.h>
+#include <mach/thread_status.h>
+
+
+/* Set up STATE to do the equivalent of `longjmp (ENV, VAL);'.  */
+
+void
+_hurd_longjmp_thread_state (void *state, jmp_buf env, int val)
+{
+  struct ppc_thread_state *ts = state;
+
+  /* XXX should we set up the FPRs as well? And how? */
+  ts->r1 = env[0].__jmpbuf[JB_GPR1];
+  ts->r2 = env[0].__jmpbuf[JB_GPR2];
+  ts->r14 = env[0].__jmpbuf[JB_GPRS+0];
+  ts->r15 = env[0].__jmpbuf[JB_GPRS+1];
+  ts->r16 = env[0].__jmpbuf[JB_GPRS+2];
+  ts->r17 = env[0].__jmpbuf[JB_GPRS+3];
+  ts->r18 = env[0].__jmpbuf[JB_GPRS+4];
+  ts->r19 = env[0].__jmpbuf[JB_GPRS+5];
+  ts->r20 = env[0].__jmpbuf[JB_GPRS+6];
+  ts->r21 = env[0].__jmpbuf[JB_GPRS+7];
+  ts->r22 = env[0].__jmpbuf[JB_GPRS+8];
+  ts->r23 = env[0].__jmpbuf[JB_GPRS+9];
+  ts->r24 = env[0].__jmpbuf[JB_GPRS+10];
+  ts->r25 = env[0].__jmpbuf[JB_GPRS+11];
+  ts->r26 = env[0].__jmpbuf[JB_GPRS+12];
+  ts->r27 = env[0].__jmpbuf[JB_GPRS+13];
+  ts->r28 = env[0].__jmpbuf[JB_GPRS+14];
+  ts->r29 = env[0].__jmpbuf[JB_GPRS+15];
+  ts->r30 = env[0].__jmpbuf[JB_GPRS+16];
+  ts->r31 = env[0].__jmpbuf[JB_GPRS+17];
+  ts->cr = env[0].__jmpbuf[JB_CR];
+  ts->r3 = val ?: 1;
+  ts->srr0 = ts->lr = env[0].__jmpbuf[JB_LR];
+}
diff --git a/sysdeps/mach/hurd/powerpc/register-dump.h b/sysdeps/mach/hurd/powerpc/register-dump.h
new file mode 100644
index 0000000000..0377175227
--- /dev/null
+++ b/sysdeps/mach/hurd/powerpc/register-dump.h
@@ -0,0 +1,120 @@
+/* Dump registers.  PowerPC/Hurd version.
+   Copyright (C) 1998, 2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sys/uio.h>
+#include <stdio-common/_itoa.h>
+
+/* This prints out the information in the following form: */
+static const char dumpform[] = "\
+Register dump:\n\
+fp0-3:   0000030%0000031% 0000032%0000033% 0000034%0000035% 0000036%0000037%\n\
+fp4-7:   0000038%0000039% 000003a%000003b% 000003c%000003d% 000003e%000003f%\n\
+fp8-11:  0000040%0000041% 0000042%0000043% 0000044%0000045% 0000046%0000047%\n\
+fp12-15: 0000048%0000049% 000004a%000004b% 000004c%000004d% 000004e%000004f%\n\
+fp16-19: 0000050%0000051% 0000052%0000053% 0000054%0000055% 0000056%0000057%\n\
+fp20-23: 0000058%0000059% 000005a%000005b% 000005c%000005d% 000005e%000005f%\n\
+fp24-27: 0000060%0000061% 0000062%0000063% 0000064%0000065% 0000066%0000067%\n\
+fp28-31: 0000068%0000069% 000006a%000006b% 000006c%000006d% 000006e%000006f%\n\
+r0 =0000002% sp =0000003% r2 =0000004% r3 =0000005%\n\
+r4 =0000006% r5 =0000007% r6 =0000008% r7 =0000009%   sr0=0000000% sr1=0000001%\n\
+r8 =000000a% r9 =000000b% r10=000000c% r11=000000d%    cr=0000022% xer=0000023%\n\
+r12=000000e% r13=000000f% r14=0000010% r15=0000011%    lr=0000024% ctr=0000025%\n\
+r16=0000012% r17=0000013% r18=0000014% r19=0000015%    mq=0000026% fcr=0000071%\n\
+r20=0000016% r21=0000017% r22=0000018% r23=0000019%   dar=0000028% dsi=0000029%\n\
+r24=000001a% r25=000001b% r26=000001c% r27=000001d%   exc=000002a%\n\
+r28=000001e% r29=000001f% r30=0000020% r31=0000021%\n\
+";
+
+/* Most of the fields are self-explanatory.  'sr0' is the next
+   instruction to execute, from SRR0, which may have some relationship
+   with the instruction that caused the exception.  'r3*' is the value
+   that will be returned in register 3 when the current system call
+   returns.  'sr1' is SRR1, bits 16-31 of which are copied from the MSR:
+
+   16 - External interrupt enable
+   17 - Privilege level (1=user, 0=supervisor)
+   18 - FP available
+   19 - Machine check enable (if clear, processor locks up on machine check)
+   20 - FP exception mode bit 0 (FP exceptions recoverable)
+   21 - Single-step trace enable
+   22 - Branch trace enable
+   23 - FP exception mode bit 1
+   25 - exception prefix (if set, exceptions are taken from 0xFFFnnnnn,
+        otherwise from 0x000nnnnn).
+   26 - Instruction address translation enabled.
+   27 - Data address translation enabled.
+   30 - Exception is recoverable (otherwise, don't try to return).
+   31 - Little-endian mode enable.
+
+   'Trap' is the address of the exception:
+
+   00200 - Machine check exception (memory parity error, for instance)
+   00300 - Data access exception (memory not mapped, see dsisr for why)
+   00400 - Instruction access exception (memory not mapped)
+   00500 - External interrupt
+   00600 - Alignment exception (see dsisr for more information)
+   00700 - Program exception (illegal/trap instruction, FP exception)
+   00800 - FP unavailable (should not be seen by user code)
+   00900 - Decrementer exception (for instance, SIGALRM)
+   00A00 - I/O controller interface exception
+   00C00 - System call exception (for instance, kill(3)).
+   00E00 - FP assist exception (optional FP instructions, etc.)
+
+   'dar' is the memory location, for traps 00300, 00400, 00600, 00A00.
+   'dsisr' has the following bits under trap 00300:
+   0 - direct-store error exception
+   1 - no page table entry for page
+   4 - memory access not permitted
+   5 - trying to access I/O controller space or using lwarx/stwcx on
+       non-write-cached memory
+   6 - access was store
+   9 - data access breakpoint hit
+   10 - segment table search failed to find translation (64-bit ppcs only)
+   11 - I/O controller instruction not permitted
+   For trap 00400, the same bits are set in SRR1 instead.
+   For trap 00600, bits 12-31 of the DSISR set to allow emulation of
+   the instruction without actually having to read it from memory.
+*/
+
+#define xtoi(x) (x >= 'a' ? x + 10 - 'a' : x - '0')
+
+static void
+register_dump (int fd, struct sigcontext *ctx)
+{
+  char buffer[sizeof(dumpform)];
+  char *bufferpos;
+  unsigned regno;
+  unsigned *regs = (unsigned *)(&ctx->sc_srr0);
+
+  memcpy(buffer, dumpform, sizeof(dumpform));
+
+  /* Generate the output.  */
+  while ((bufferpos = memchr (buffer, '%', sizeof(dumpform))))
+    {
+      regno = xtoi (bufferpos[-1]) | xtoi (bufferpos[-2]) << 4;
+      memset (bufferpos-2, '0', 3);
+      _itoa_word (regs[regno], bufferpos+1, 16, 0);
+    }
+
+  /* Write the output.  */
+  write (fd, buffer, sizeof(buffer));
+}
+
+#define REGISTER_DUMP \
+  register_dump (fd, ctx)
diff --git a/sysdeps/mach/hurd/powerpc/sigreturn.c b/sysdeps/mach/hurd/powerpc/sigreturn.c
new file mode 100644
index 0000000000..18e37a3d41
--- /dev/null
+++ b/sysdeps/mach/hurd/powerpc/sigreturn.c
@@ -0,0 +1,186 @@
+/* Return from signal handler for Hurd.  PowerPC version.
+   Copyright (C) 1996,97,98,2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <hurd.h>
+#include <hurd/signal.h>
+#include <hurd/threadvar.h>
+#include <stdlib.h>
+
+int
+__sigreturn (struct sigcontext *scp)
+{
+  struct hurd_sigstate *ss;
+  mach_port_t *reply_port;
+
+  if (scp == NULL || (scp->sc_mask & _SIG_CANT_MASK))
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+  ss = _hurd_self_sigstate ();
+  __spin_lock (&ss->lock);
+
+  /* Restore the set of blocked signals, and the intr_port slot.  */
+  ss->blocked = scp->sc_mask;
+  ss->intr_port = scp->sc_intr_port;
+
+  /* Check for pending signals that were blocked by the old set.  */
+  if (ss->pending & ~ss->blocked)
+    {
+      /* There are pending signals that just became unblocked.  Wake up the
+	 signal thread to deliver them.  But first, squirrel away SCP where
+	 the signal thread will notice it if it runs another handler, and
+	 arrange to have us called over again in the new reality.  */
+      ss->context = scp;
+      __spin_unlock (&ss->lock);
+      __msg_sig_post (_hurd_msgport, 0, 0, __mach_task_self ());
+      /* If a pending signal was handled, sig_post never returned.  */
+      __spin_lock (&ss->lock);
+      ss->context = NULL;
+    }
+
+  if (scp->sc_onstack)
+    {
+      ss->sigaltstack.ss_flags &= ~SS_ONSTACK; /* XXX threadvars */
+      /* XXX cannot unlock until off sigstack */
+      abort ();
+    }
+  else
+    __spin_unlock (&ss->lock);
+
+  /* Destroy the MiG reply port used by the signal handler, and restore the
+     reply port in use by the thread when interrupted.  */
+  reply_port =
+    (mach_port_t *) __hurd_threadvar_location (_HURD_THREADVAR_MIG_REPLY);
+  if (*reply_port)
+    {
+      mach_port_t port = *reply_port;
+
+      /* Assigning MACH_PORT_DEAD here tells libc's mig_get_reply_port not to
+	 get another reply port, but avoids mig_dealloc_reply_port trying to
+	 deallocate it after the receive fails (which it will, because the
+	 reply port will be bogus, whether we do this or not).  */
+      *reply_port = MACH_PORT_DEAD;
+
+      __mach_port_destroy (__mach_task_self (), port);
+    }
+  *reply_port = scp->sc_reply_port;
+
+  /* Restore FPU state.  */
+#define restore_fpr(n) \
+  asm volatile ("lfd " #n ",%0(31)" : : "i" (n * 4))
+
+  asm volatile ("mr 31,%0" : : "r" (scp->sc_fprs));
+
+  /* Restore the floating-point control/status register.  */
+  asm volatile ("lfd 0,256(31)");
+  asm volatile ("mtfsf 0xff,0");
+
+  /* Restore floating-point registers. */
+  restore_fpr (0);
+  restore_fpr (1);
+  restore_fpr (2);
+  restore_fpr (3);
+  restore_fpr (4);
+  restore_fpr (5);
+  restore_fpr (6);
+  restore_fpr (7);
+  restore_fpr (8);
+  restore_fpr (9);
+  restore_fpr (10);
+  restore_fpr (11);
+  restore_fpr (12);
+  restore_fpr (13);
+  restore_fpr (14);
+  restore_fpr (15);
+  restore_fpr (16);
+  restore_fpr (17);
+  restore_fpr (18);
+  restore_fpr (19);
+  restore_fpr (20);
+  restore_fpr (21);
+  restore_fpr (22);
+  restore_fpr (23);
+  restore_fpr (24);
+  restore_fpr (25);
+  restore_fpr (26);
+  restore_fpr (27);
+  restore_fpr (28);
+  restore_fpr (29);
+  restore_fpr (30);
+  restore_fpr (31);
+
+  /* Load all the registers from the sigcontext.  */
+#define restore_gpr(n) \
+  asm volatile ("lwz " #n ",%0(31)" : : "i" (n * 4))
+
+  asm volatile ("addi 31,31,-188");  /* r31 = scp->gprs */
+
+  /* Restore the special purpose registers.  */
+  asm volatile ("lwz 0,128(31); mtcr 0");
+  asm volatile ("lwz 0,132(31); mtxer 0");
+  asm volatile ("lwz 0,136(31); mtlr 0");
+  asm volatile ("lwz 0,-8(31); mtctr 0");  /* XXX this is the PC */
+#if 0
+  asm volatile ("lwz 0,144(31); mtmq %0");  /* PPC601 only */
+#endif
+
+  /* Restore the normal registers.  */
+  restore_gpr (0);
+  restore_gpr (1);
+  restore_gpr (2);
+  restore_gpr (3);
+  restore_gpr (4);
+  restore_gpr (5);
+  restore_gpr (6);
+  restore_gpr (7);
+  restore_gpr (8);
+  restore_gpr (9);
+  restore_gpr (10);
+  restore_gpr (11);
+  restore_gpr (12);
+  restore_gpr (13);
+  restore_gpr (14);
+  restore_gpr (15);
+  restore_gpr (16);
+  restore_gpr (17);
+  restore_gpr (18);
+  restore_gpr (19);
+  restore_gpr (20);
+  restore_gpr (21);
+  restore_gpr (22);
+  restore_gpr (23);
+  restore_gpr (24);
+  restore_gpr (25);
+  restore_gpr (26);
+  restore_gpr (27);
+  restore_gpr (28);
+  restore_gpr (29);
+  restore_gpr (30);
+  restore_gpr (31);
+
+  /* Return. */
+  asm volatile ("bctr");  /* XXX CTR is not restored! */
+
+  /* NOTREACHED */
+  return -1;
+}
+
+weak_alias (__sigreturn, sigreturn)
diff --git a/sysdeps/mach/hurd/powerpc/static-start.S b/sysdeps/mach/hurd/powerpc/static-start.S
new file mode 100644
index 0000000000..209972c426
--- /dev/null
+++ b/sysdeps/mach/hurd/powerpc/static-start.S
@@ -0,0 +1,59 @@
+/* Startup code for statically linked Hurd/PowerPC binaries.
+   Copyright (C) 1998,2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+
+ /* These are the various addresses we require.  */
+	.section ".rodata"
+	.align	2
+	weak_extern(_init)
+	weak_extern(_fini)
+L(start_addresses):
+	.long	_SDA_BASE_
+	.long	JUMPTARGET(main)
+	.long	JUMPTARGET(_init)
+	.long	JUMPTARGET(_fini)
+	ASM_SIZE_DIRECTIVE(L(start_addresses))
+
+	.section ".text"
+ENTRY(_start)
+ /* Save the stack pointer to pass to _hurd_stack_setup.  */
+	mr	r3,r1
+ /* Set up an initial stack frame.  */
+	li	r0,0
+	stwu	r0,-16(r1)
+ /* Call _hurd_stack_setup.  */
+	bl	JUMPTARGET(_hurd_stack_setup)
+ /* Pass the argument data to __libc_start_main.  */
+	addi	r9,r1,16
+ /* Clear the LR.  */
+	li	r0,0
+	mtlr	r0
+ /* Set r13 to point at the 'small data area', and put the address of
+    start_addresses in r8...  */
+	lis	r8,L(start_addresses)@ha
+	lwzu	r13,L(start_addresses)@l(r8)
+ /* and continue in libc-start, in glibc.  */
+	b	JUMPTARGET(__libc_start_main)
+END(_start)
+
+/* Define a symbol for the first piece of initialized data.  */
+	.section ".data"
+__data_start:
+weak_alias (__data_start, data_start)
diff --git a/sysdeps/mach/hurd/powerpc/trampoline.c b/sysdeps/mach/hurd/powerpc/trampoline.c
new file mode 100644
index 0000000000..4e5d675258
--- /dev/null
+++ b/sysdeps/mach/hurd/powerpc/trampoline.c
@@ -0,0 +1,256 @@
+/* Set thread_state for sighandler, and sigcontext to recover.  For PowerPC.
+   Copyright (C) 1994,95,96,97,98,99,2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <hurd/signal.h>
+#include <hurd/userlink.h>
+#include "thread_state.h"
+#include <assert.h>
+#include <errno.h>
+#include "hurdfault.h"
+#include "intr-msg.h"
+
+struct sigcontext *
+_hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler,
+			int signo, struct hurd_signal_detail *detail,
+			volatile int rpc_wait,
+			struct machine_thread_all_state *state)
+{
+  void trampoline (void);
+  void rpc_wait_trampoline (void);
+  void *volatile sigsp;
+  struct sigcontext *scp;
+
+  if (ss->context)
+    {
+      /* We have a previous sigcontext that sigreturn was about
+	 to restore when another signal arrived.  We will just base
+	 our setup on that.  */
+      if (! _hurdsig_catch_memory_fault (ss->context))
+	{
+	  memcpy (&state->basic, &ss->context->sc_ppc_thread_state,
+		  sizeof (state->basic));
+	  memcpy (&state->exc, &ss->context->sc_ppc_exc_state,
+		  sizeof (state->exc));
+	  memcpy (&state->fpu, &ss->context->sc_ppc_float_state,
+		  sizeof (state->fpu));
+	  state->set = (1 << PPC_THREAD_STATE) | (1 << PPC_EXCEPTION_STATE)
+	    | (1 << PPC_FLOAT_STATE);
+	}
+    }
+
+  if (! machine_get_basic_state (ss->thread, state))
+    return NULL;
+
+  if ((ss->actions[signo].sa_flags & SA_ONSTACK) &&
+      !(ss->sigaltstack.ss_flags & (SS_DISABLE|SS_ONSTACK)))
+    {
+      sigsp = ss->sigaltstack.ss_sp + ss->sigaltstack.ss_size;
+      ss->sigaltstack.ss_flags |= SS_ONSTACK;
+      /* XXX need to set up base of new stack for
+	 per-thread variables, cthreads.  */
+    }
+  else
+    sigsp = (char *) state->basic.SP;
+
+  /* Set up the sigcontext structure on the stack.  This is all the stack
+     needs, since the args are passed in registers (below).  */
+  sigsp -= sizeof (*scp);
+  scp = sigsp;
+  sigsp -= 16;  /* Reserve some space for a stack frame.  */
+
+  if (_hurdsig_catch_memory_fault (scp))
+    {
+      /* We got a fault trying to write the stack frame.
+	 We cannot set up the signal handler.
+	 Returning NULL tells our caller, who will nuke us with a SIGILL.  */
+      return NULL;
+    }
+  else
+    {
+      int ok;
+
+      /* Set up the sigcontext from the current state of the thread.  */
+
+      scp->sc_onstack = ss->sigaltstack.ss_flags & SS_ONSTACK ? 1 : 0;
+
+      /* struct sigcontext is laid out so that starting at sc_srr0
+	 mimics a struct ppc_thread_state.  */
+      memcpy (&scp->sc_ppc_thread_state,
+	      &state->basic, sizeof (state->basic));
+
+      /* struct sigcontext is laid out so that starting at sc_dar
+	 mimics a struct ppc_exc_state.  */
+      ok = machine_get_state (ss->thread, state, PPC_EXCEPTION_STATE,
+			       &state->exc, &scp->sc_ppc_exc_state,
+			       sizeof (state->exc));
+
+      /* struct sigcontext is laid out so that starting at sc_fprs[0]
+	 mimics a struct ppc_float_state.  */
+      if (ok)
+	ok = machine_get_state (ss->thread, state, PPC_FLOAT_STATE,
+				&state->fpu, &scp->sc_ppc_float_state,
+				sizeof (state->fpu));
+
+      _hurdsig_end_catch_fault ();
+
+      if (!ok)
+	return NULL;
+    }
+
+  /* Modify the thread state to call the trampoline code on the new stack.  */
+  if (rpc_wait)
+    {
+      /* The signalee thread was blocked in a mach_msg_trap system call,
+	 still waiting for a reply.  We will have it run the special
+	 trampoline code which retries the message receive before running
+	 the signal handler.
+
+	 To do this we change the OPTION argument in its registers to
+	 enable only message reception, since the request message has
+	 already been sent.  */
+
+      /* The system call arguments are stored in consecutive registers
+	 starting with r3.  */
+      struct mach_msg_trap_args *args = (void *) &state->basic.r3;
+
+      if (_hurdsig_catch_memory_fault (args))
+	{
+	  /* Faulted accessing ARGS.  Bomb.  */
+	  return NULL;
+	}
+
+      assert (args->option & MACH_RCV_MSG);
+      /* Disable the message-send, since it has already completed.  The
+	 calls we retry need only wait to receive the reply message.  */
+      args->option &= ~MACH_SEND_MSG;
+
+      /* Limit the time to receive the reply message, in case the server
+	 claimed that `interrupt_operation' succeeded but in fact the RPC
+	 is hung.  */
+      args->option |= MACH_RCV_TIMEOUT;
+      args->timeout = _hurd_interrupted_rpc_timeout;
+
+      _hurdsig_end_catch_fault ();
+
+      state->basic.PC = (int) rpc_wait_trampoline;
+      /* After doing the message receive, the trampoline code will need to
+	 update the r3 value to be restored by sigreturn.  To simplify
+	 the assembly code, we pass the address of its slot in SCP to the
+	 trampoline code in r10.  */
+      state->basic.r10 = (long int) &scp->sc_gprs[3];
+      /* We must preserve the mach_msg_trap args in r3..r9.
+	 Pass the handler args to the trampoline code in r11..r13.  */
+      state->basic.r11 = signo;
+      state->basic.r12 = detail->code;
+      state->basic.r13 = (int) scp;
+    }
+  else
+    {
+      state->basic.PC = (int) trampoline;
+      state->basic.r3 = signo;
+      state->basic.r4 = detail->code;
+      state->basic.r5 = (int) scp;
+    }
+
+  state->basic.r1 = (int) sigsp;  /* r1 is the stack pointer.  */
+
+  /* We pass the handler function to the trampoline code in ctr.  */
+  state->basic.ctr = (int) handler;
+  /* In r15, we store the address of __sigreturn itself,
+     for the trampoline code to use.  */
+  state->basic.r15 = (int) &__sigreturn;
+  /* In r16, we save the SCP value to pass to __sigreturn
+     after the handler returns.  */
+  state->basic.r16 = (int) scp;
+
+  /* In r3, we store a pointer to the registers in STATE so that the
+     trampoline code can load the registers from that.  For some reason,
+     thread_set_state doesn't set all registers.  */
+  state->basic.r17 = state->basic.r3;  /* Store the real r3 in r17.  */
+  state->basic.r3 = (int) &state->basic.r0;
+
+  return scp;
+}
+
+/* The trampoline code follows.  This used to be located inside
+   _hurd_setup_sighandler, but was optimized away by gcc 2.95.  */
+
+/* This function sets some registers which the trampoline code uses
+   and which are not automatically set by thread_set_state.
+   In r3 we have a pointer to the registers in STATE.  */
+asm ("trampoline_load_registers:\n"
+     "lwz 17,68(3)\n"  /* The real r3.  */
+     "lwz 4,16(3)\n"
+     "lwz 5,20(3)\n"
+     "lwz 6,24(3)\n"
+     "lwz 7,28(3)\n"
+     "lwz 8,32(3)\n"
+     "lwz 9,36(3)\n"
+     "lwz 10,40(3)\n"
+     "lwz 11,44(3)\n"
+     "lwz 12,48(3)\n"
+     "lwz 13,52(3)\n"
+     "lwz 14,56(3)\n"
+     "lwz 15,60(3)\n"
+     "lwz 16,64(3)\n"
+     "mr 3,17\n"
+     "blr\n");
+
+asm ("rpc_wait_trampoline:\n");
+  /* This is the entry point when we have an RPC reply message to receive
+     before running the handler.  The MACH_MSG_SEND bit has already been
+     cleared in the OPTION argument in our registers.  For our convenience,
+     r10 points to the sc_regs[3] member of the sigcontext (saved r3).  */
+
+asm (/* Retry the interrupted mach_msg system call.  */
+     "bl trampoline_load_registers\n"
+     "li 0, -25\n"		/* mach_msg_trap */
+     "sc\n"
+     /* When the sigcontext was saved, r3 was MACH_RCV_INTERRUPTED.  But
+	now the message receive has completed and the original caller of
+	the RPC (i.e. the code running when the signal arrived) needs to
+	see the final return value of the message receive in r3.  So
+	store the new r3 value into the sc_regs[3] member of the sigcontext
+	(whose address is in r10 to make this code simpler).  */
+     "stw 3, 0(10)\n"
+     /* Since the argument registers needed to have the mach_msg_trap
+	arguments, we've stored the arguments to the handler function
+	in registers r11..r13 of the state structure.  */
+     "mr 3,11\n"
+     "mr 4,12\n"
+     "mr 5,13\n");
+
+asm ("trampoline:\n");
+  /* Entry point for running the handler normally.  The arguments to the
+     handler function are already in the standard registers:
+
+       r3	SIGNO
+       r4	SIGCODE
+       r5	SCP
+
+     r16 also contains SCP; this value is callee-saved (and so should not get
+     clobbered by running the handler).  We use this saved value to pass to
+     __sigreturn, so the handler can clobber the argument registers if it
+     likes.  */
+asm ("bl trampoline_load_registers\n"
+     "bctrl\n"		/* Call the handler function.  */
+     "mtctr 15\n"	/* Copy &__sigreturn to CTR.  */
+     "mr 3,16\n"	/* Copy the saved SCP to r3.  */
+     "bctr\n"		/* Call __sigreturn (SCP).  */
+     );