S/390 31 & 64 bit target and GNU/Linux native support.

Contributed by D.J. Barrow <djbarrow@de.ibm.com> of IBM.
* s390-nat.c, s390-tdep.c: New file.
* config/s390/nm-linux.h, config/s390/s390.mh: New file.
* config/s390/s390.mt, config/s390/s390x.mt: New file.
* config/s390/tm-linux.h, config/s390/tm-s390.h: New file.
* config/s390/xm-linux.h: New file.
* NEWS: Update.
* MAINTAINERS: Update.

12 files changed, 2141 insertions, 0 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2acf23d..40e45e9 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,17 @@
 2001-10-13  Andrew Cagney  <ac131313@redhat.com>
 
+	S/390 31 & 64 bit target and GNU/Linux native support.
+	Contributed by D.J. Barrow <djbarrow@de.ibm.com> of IBM.
+	* s390-nat.c, s390-tdep.c: New file.
+	* config/s390/nm-linux.h, config/s390/s390.mh: New file.
+	* config/s390/s390.mt, config/s390/s390x.mt: New file.
+	* config/s390/tm-linux.h, config/s390/tm-s390.h: New file.
+	* config/s390/xm-linux.h: New file.
+	* NEWS: Update.
+	* MAINTAINERS: Update.
+
+2001-10-13  Andrew Cagney  <ac131313@redhat.com>
+
 	From 2001-07-09 D.J. Barrow <djbarrow@de.ibm.com>:
         * gdbarch.sh: Fixed CALL_DUMMY_BREAKPOINT_OFFSET to check
 	CALL_DUMMY_BREAKPOINT_OFFSET_P.
diff --git a/gdb/MAINTAINERS b/gdb/MAINTAINERS
index 9081d0c..db41592 100644
--- a/gdb/MAINTAINERS
+++ b/gdb/MAINTAINERS
@@ -128,6 +128,9 @@ maintainer works with the native maintainer when resolving API issues.
 	rs6000		--target=rs6000-ibm-aix3.2,rs6000-ibm-aix4.1 ,-Werror
 			(see rs6000 native and ppc target)
 
+	s390		--target=s390-linux ,-Werror
+			(contact DJ Barrow	djbarrow@de.ibm.com)
+
 	sh		--target=sh-hms,sh-elf ,-Werror
 			Elena Zannoni		ezannoni@redhat.com
 
diff --git a/gdb/NEWS b/gdb/NEWS
index f88f28b..6780190 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -10,6 +10,7 @@ x86 FreeBSD 3.x and 4.x				i[3456]86*-freebsd[34]*
 MIPS Linux					mips*-*-linux*
 MIPS SGI Irix 6.x				mips*-sgi-irix6*
 ia64 AIX					ia64-*-aix*
+s390 and s390x Linux				{s390,s390x}-*-linux*
 
 * New targets
 
diff --git a/gdb/config/s390/nm-linux.h b/gdb/config/s390/nm-linux.h
new file mode 100644
index 0000000..ddf298e
--- /dev/null
+++ b/gdb/config/s390/nm-linux.h
@@ -0,0 +1,92 @@
+/* Native support for Linux for S390
+   Copyright 2001 Free Software Foundation, Inc.
+   Ported by D.J. Barrow for IBM Deutschland Entwicklung GmbH, IBM Corporation.
+   derived from i390-nmlinux.h
+   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_LINUX_H
+#define NM_LINUX_H
+
+#include "config/nm-linux.h"
+
+#define REGISTER_U_ADDR(addr, blockend, regno) \
+	(addr) = s390_register_u_addr((blockend),(regno));
+extern int s390_register_u_addr (int, int);
+
+/* Return sizeof user struct to callers in less machine dependent routines */
+
+#define KERNEL_U_SIZE kernel_u_size()
+extern int kernel_u_size (void);
+
+#define U_REGS_OFFSET 0
+
+
+/* We define this if link.h is available, because with ELF we use SVR4 style
+   shared libraries. */
+
+#ifdef HAVE_LINK_H
+#define SVR4_SHARED_LIBS
+#include "solib.h"		/* Support for shared libraries. */
+#endif
+
+
+/* WATCHPOINT SPECIFIC STUFF */
+
+#define TARGET_HAS_HARDWARE_WATCHPOINTS
+#define HAVE_CONTINUABLE_WATCHPOINT
+#define HAVE_STEPPABLE_WATCHPOINT
+#define target_insert_watchpoint(addr, len, type)  \
+  s390_insert_watchpoint (PIDGET (inferior_ptid), addr, len, type)
+
+#define target_remove_watchpoint(addr, len, type)  \
+  s390_remove_watchpoint (PIDGET (inferior_ptid), addr, len)
+
+extern int watch_area_cnt;
+/* gdb if really stupid & calls this all the time without a
+   watchpoint even being set */
+#define STOPPED_BY_WATCHPOINT(W)  \
+  (watch_area_cnt&&s390_stopped_by_watchpoint (PIDGET(inferior_ptid)))
+
+extern CORE_ADDR s390_stopped_by_watchpoint (int);
+
+/*
+  Type can be 1 for a read_watchpoint or 2 for an access watchpoint.
+ */
+extern int s390_insert_watchpoint (int pid, CORE_ADDR addr, int len, int rw);
+extern int s390_remove_watchpoint (int pid, CORE_ADDR addr, int len);
+#define TARGET_CAN_USE_HARDWARE_WATCHPOINT(type, cnt, ot) \
+	 (((type) == bp_hardware_watchpoint)|| \
+	 ((type) == bp_watchpoint)|| \
+	 ((type) == bp_read_watchpoint) || \
+         ((type) == bp_access_watchpoint))
+
+#undef 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)
+
+/* Needed for s390x */
+#define PTRACE_ARG3_TYPE long
+#define PTRACE_XFER_TYPE long
+#endif /* nm_linux.h */
diff --git a/gdb/config/s390/s390.mh b/gdb/config/s390/s390.mh
new file mode 100644
index 0000000..fa953b4
--- /dev/null
+++ b/gdb/config/s390/s390.mh
@@ -0,0 +1,15 @@
+# Host: S390, running Linux
+
+XM_FILE= xm-linux.h
+XDEPFILES= ser-tcp.o
+XM_CLIBS=
+
+NAT_FILE= nm-linux.h
+NATDEPFILES= infptrace.o solib.o inftarg.o fork-child.o corelow.o \
+	   s390-nat.o linux-thread.o core-aout.o core-regset.o
+# post 5.0 natdepfiles.
+NATDEPFILES+= thread-db.o lin-lwp.o proc-service.o 
+LOADLIBES = -ldl -rdynamic
+
+
+
diff --git a/gdb/config/s390/s390.mt b/gdb/config/s390/s390.mt
new file mode 100644
index 0000000..87a5ba3
--- /dev/null
+++ b/gdb/config/s390/s390.mt
@@ -0,0 +1,7 @@
+# Target: S390 running Linux
+TM_FILE= tm-linux.h
+TDEPFILES=s390-tdep.o solib.o
+# Post 5.0 tdep-files
+TDEPFILES+=solib-svr4.o solib-legacy.o
+GDB_MULTI_ARCH=GDB_MULTI_ARCH_PARTIAL
+GDBSERVER_DEPFILES= low-linux.o s390-tdep.o s390-nat.o
diff --git a/gdb/config/s390/s390x.mt b/gdb/config/s390/s390x.mt
new file mode 100644
index 0000000..310021d
--- /dev/null
+++ b/gdb/config/s390/s390x.mt
@@ -0,0 +1,9 @@
+# Target: S390 running Linux
+TM_FILE= tm-linux.h
+TDEPFILES=s390-tdep.o solib.o
+# Post 5.0 tdep-files
+TDEPFILES+=solib-svr4.o solib-legacy.o
+GDB_MULTI_ARCH=GDB_MULTI_ARCH_PARTIAL
+GDBSERVER_DEPFILES= low-linux.o s390-tdep.o s390-nat.o
+# needed for gdbserver.
+MT_CFLAGS= -DCONFIG_ARCH_S390X
diff --git a/gdb/config/s390/tm-linux.h b/gdb/config/s390/tm-linux.h
new file mode 100644
index 0000000..ce47ccc
--- /dev/null
+++ b/gdb/config/s390/tm-linux.h
@@ -0,0 +1,42 @@
+/* Target definitions for GDB for a s390 running Linux.
+   Copyright 2001 Free Software Foundation, Inc.
+   Contributed by D.J. Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
+   for IBM Deutschland Entwicklung GmbH, IBM Corporation.
+
+   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_LINUX_H
+#define TM_LINUX_H
+#ifdef GDBSERVER
+#define S390_GNULINUX_TARGET
+#endif /* GDBSERVER */
+#undef  TARGET_ELF64
+#define TARGET_ELF64 (gdbarch_tdep (current_gdbarch)->intreg_size==8)
+
+#include "config/tm-linux.h"
+
+/* Zap several macros defined in the above header so that multi-arch
+   can safely re-define them.  The ``correct fix'' involves
+   eliminating either the above include or even this file.  */
+#undef SKIP_TRAMPOLINE_CODE
+
+#include "s390/tm-s390.h"
+
+
+
+#endif /* TM_LINUX_H */
diff --git a/gdb/config/s390/tm-s390.h b/gdb/config/s390/tm-s390.h
new file mode 100644
index 0000000..da9f621
--- /dev/null
+++ b/gdb/config/s390/tm-s390.h
@@ -0,0 +1,115 @@
+/* Macro definitions for GDB on an S390.
+   Copyright 2001 Free Software Foundation, Inc.
+   Contributed by D.J. Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
+   for IBM Deutschland Entwicklung GmbH, IBM Corporation.
+
+   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.  */
+
+#if !defined(TM_S390_H)
+#define TM_S390_H 1
+
+#define S390_NUM_GPRS      (16)
+#define S390_GPR_SIZE      REGISTER_SIZE
+#define S390_PSW_MASK_SIZE REGISTER_SIZE
+#define S390_PSW_ADDR_SIZE REGISTER_SIZE
+#define S390_NUM_FPRS      (16)
+#define S390_FPR_SIZE      (8)
+#define S390_FPC_SIZE      (4)
+#define S390_FPC_PAD_SIZE  (4)	/* gcc insists on aligning the fpregs */
+#define S390_NUM_CRS       (16)
+#define S390_CR_SIZE       REGISTER_SIZE
+#define S390_NUM_ACRS      (16)
+#define S390_ACR_SIZE      (4)
+
+#define S390_NUM_REGS      (2+S390_NUM_GPRS+S390_NUM_ACRS+S390_NUM_CRS+1+S390_NUM_FPRS)
+#define S390_FIRST_ACR     (2+S390_NUM_GPRS)
+#define S390_LAST_ACR      (S390_FIRST_ACR+S390_NUM_ACRS-1)
+#define S390_FIRST_CR      (S390_FIRST_ACR+S390_NUM_ACRS)
+#define S390_LAST_CR       (S390_FIRST_CR+S390_NUM_CRS-1)
+
+#define S390_PSWM_REGNUM    0
+#define S390_PC_REGNUM      1
+#define	S390_GP0_REGNUM     2	/* GPR register 0 */
+#define S390_GP_LAST_REGNUM (S390_GP0_REGNUM+S390_NUM_GPRS-1)
+/* Usually return address */
+#define S390_RETADDR_REGNUM (S390_GP0_REGNUM+14)
+/* Contains address of top of stack */
+#define S390_SP_REGNUM      (S390_GP0_REGNUM+15)
+/* needed in findvar.c still */
+#define S390_FP_REGNUM     S390_SP_REGNUM
+#define S390_FRAME_REGNUM  (S390_GP0_REGNUM+11)
+#define S390_FPC_REGNUM    (S390_GP0_REGNUM+S390_NUM_GPRS+S390_NUM_ACRS+S390_NUM_CRS)
+/* FPR (Floating point) register 0 */
+#define S390_FP0_REGNUM    (S390_FPC_REGNUM+1)
+/* Last floating point register */
+#define S390_FPLAST_REGNUM (S390_FP0_REGNUM+S390_NUM_FPRS-1)
+#define S390_LAST_REGNUM   S390_FPLAST_REGNUM
+
+
+#define S390_ACR0_OFFSET ((S390_PSW_MASK_SIZE+S390_PSW_ADDR_SIZE)+(S390_GPR_SIZE*S390_NUM_GPRS))
+#define S390_CR0_OFFSET (S390_ACR0_OFFSET+(S390_ACR_SIZE*S390_NUM_ACRS))
+#define S390_FPC_OFFSET (S390_CR0_OFFSET+(S390_CR_SIZE*S390_NUM_CRS))
+#define S390_FP0_OFFSET (S390_FPC_OFFSET+(S390_FPC_SIZE+S390_FPC_PAD_SIZE))
+#define S390_GPR6_STACK_OFFSET (GDB_TARGET_IS_ESAME ? 48:24)
+
+#define S390_REGISTER_BYTES ((4+4)+(4*S390_NUM_GPRS)+(4*S390_NUM_ACRS)+ \
+(4*S390_NUM_CRS)+(S390_FPC_SIZE+S390_FPC_PAD_SIZE)+(S390_FPR_SIZE*S390_NUM_FPRS))
+
+#define S390X_REGISTER_BYTES ((8+8)+(8*S390_NUM_GPRS)+(4*S390_NUM_ACRS)+ \
+(8*S390_NUM_CRS)+(S390_FPC_SIZE+S390_FPC_PAD_SIZE)+(S390_FPR_SIZE*S390_NUM_FPRS))
+
+#ifdef GDBSERVER
+
+int s390_register_byte (int reg_nr);
+#define REGISTER_BYTE(reg_nr) s390_register_byte(reg_nr)
+#define PC_REGNUM S390_PC_REGNUM
+#define NUM_REGS  S390_NUM_REGS
+#define NUM_FREGS S390_NUM_FPRS
+#define FP_REGNUM S390_FP_REGNUM
+#define SP_REGNUM S390_SP_REGNUM
+/* Obviously ptrace for user program tracing cannot be allowed
+  mess with control registers (except per registers for hardware watchpoints),
+  when we add kernel debugging we may need to alter these macros. */
+int s390_cannot_fetch_register (int regno);
+#define CANNOT_FETCH_REGISTER(regno) s390_cannot_fetch_register(regno)
+#define CANNOT_STORE_REGISTER(regno) s390_cannot_fetch_register(regno)
+
+#if CONFIG_ARCH_S390X
+
+int s390x_register_raw_size (int reg_nr);
+#define REGISTER_RAW_SIZE(reg_nr) s390x_register_raw_size(reg_nr)
+#define GDB_TARGET_IS_ESAME (1)
+#define REGISTER_SIZE       (8)
+#define REGISTER_BYTES S390X_REGISTER_BYTES
+
+#else /*  CONFIG_ARCH_S390X */
+
+int s390_register_raw_size (int reg_nr);
+#define REGISTER_RAW_SIZE(reg_nr) s390_register_raw_size(reg_nr)
+#define GDB_TARGET_IS_ESAME (0)
+#define REGISTER_SIZE       (4)
+#define REGISTER_BYTES S390_REGISTER_BYTES
+
+#endif /* CONFIG_ARCH_S390X */
+
+#else /* GDBSERVER */
+
+#define GDB_TARGET_IS_ESAME (TARGET_ARCHITECTURE->mach == bfd_mach_s390_esame)
+
+#endif /* GDBSERVER */
+#endif /* ifndef TM_S390_H */
diff --git a/gdb/config/s390/xm-linux.h b/gdb/config/s390/xm-linux.h
new file mode 100644
index 0000000..5c5955c
--- /dev/null
+++ b/gdb/config/s390/xm-linux.h
@@ -0,0 +1,33 @@
+/* Native support for GNU/Linux, for GDB, the GNU debugger.
+   Copyright 2001 Free Software Foundation, Inc.
+   Contributed by D.J. Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
+   for IBM Deutschland Entwicklung GmbH, IBM Corporation.
+
+   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_LINUX_H
+#define XM_LINUX_H
+
+#define HOST_BYTE_ORDER BIG_ENDIAN
+
+
+/* This is the amount to subtract from u.u_ar0
+   to get the offset in the core file of the register values.  */
+#define KERNEL_U_ADDR 0x0
+
+#endif /* #ifndef XM_LINUX_H */
diff --git a/gdb/s390-nat.c b/gdb/s390-nat.c
new file mode 100644
index 0000000..623c3d1
--- /dev/null
+++ b/gdb/s390-nat.c
@@ -0,0 +1,308 @@
+/* S390 native-dependent code for GDB, the GNU debugger.
+   Copyright 2001 Free Software Foundation, Inc
+   Contributed by D.J. Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
+   for IBM Deutschland Entwicklung GmbH, IBM Corporation.
+   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 "tm.h"
+#include <asm/ptrace.h>
+#include <sys/ptrace.h>
+#include <asm/processor.h>
+#include <sys/procfs.h>
+#include <sys/user.h>
+#include <value.h>
+#include <sys/ucontext.h>
+#ifndef offsetof
+#define offsetof(type,member) ((size_t) &((type *)0)->member)
+#endif
+
+
+int
+s390_register_u_addr (int blockend, int regnum)
+{
+  int retval;
+
+  if (regnum >= S390_GP0_REGNUM && regnum <= S390_GP_LAST_REGNUM)
+    retval = PT_GPR0 + ((regnum - S390_GP0_REGNUM) * S390_GPR_SIZE);
+  else if (regnum >= S390_PSWM_REGNUM && regnum <= S390_PC_REGNUM)
+    retval = PT_PSWMASK + ((regnum - S390_PSWM_REGNUM) * S390_PSW_MASK_SIZE);
+  else if (regnum == S390_FPC_REGNUM)
+    retval = PT_FPC;
+  else if (regnum >= S390_FP0_REGNUM && regnum <= S390_FPLAST_REGNUM)
+    retval =
+#if CONFIG_ARCH_S390X
+      PT_FPR0
+#else
+      PT_FPR0_HI
+#endif
+      + ((regnum - S390_FP0_REGNUM) * S390_FPR_SIZE);
+  else if (regnum >= S390_FIRST_ACR && regnum <= S390_LAST_ACR)
+    retval = PT_ACR0 + ((regnum - S390_FIRST_ACR) * S390_ACR_SIZE);
+  else if (regnum >= (S390_FIRST_CR + 9) && regnum <= (S390_FIRST_CR + 11))
+    retval = PT_CR_9 + ((regnum - (S390_FIRST_CR + 9)) * S390_CR_SIZE);
+  else
+    {
+#ifdef GDBSERVER
+      error
+#else
+      internal_error
+#endif
+	("s390_register_u_addr invalid regnum %s %d regnum=%d", __FILE__,
+	 (int) __LINE__, regnum);
+      retval = 0;
+    }
+  return retval + blockend;
+}
+
+#ifndef GDBSERVER
+/* watch_areas are required if you put 2 or more watchpoints on the same 
+   address or overlapping areas gdb will call us to delete the watchpoint 
+   more than once when we try to delete them.
+   attempted reference counting to reduce the number of areas unfortunately
+   they didn't shrink when areas had to be split overlapping occurs. */
+struct watch_area;
+typedef struct watch_area watch_area;
+struct watch_area
+{
+  watch_area *next;
+  CORE_ADDR lo_addr;
+  CORE_ADDR hi_addr;
+};
+
+static watch_area *watch_base = NULL;
+int watch_area_cnt = 0;
+static CORE_ADDR watch_lo_addr = 0, watch_hi_addr = 0;
+
+
+
+CORE_ADDR
+s390_stopped_by_watchpoint (int pid)
+{
+  per_lowcore_bits per_lowcore;
+  ptrace_area parea;
+
+  parea.len = sizeof (per_lowcore);
+  parea.process_addr = (addr_t) & per_lowcore;
+  parea.kernel_addr = offsetof (struct user_regs_struct, per_info.lowcore);
+  ptrace (PTRACE_PEEKUSR_AREA, pid, &parea);
+  return ((per_lowcore.perc_storage_alteration == 1) &&
+	  (per_lowcore.perc_store_real_address == 0));
+}
+
+
+void
+s390_fix_watch_points (int pid)
+{
+  per_struct per_info;
+  ptrace_area parea;
+
+  parea.len = sizeof (per_info);
+  parea.process_addr = (addr_t) & per_info;
+  parea.kernel_addr = PT_CR_9;
+  ptrace (PTRACE_PEEKUSR_AREA, pid, &parea);
+  /* The kernel automatically sets the psw for per depending */
+  /* on whether the per control registers are set for event recording */
+  /* & sets cr9 & cr10 appropriately also */
+  if (watch_area_cnt)
+    {
+      per_info.control_regs.bits.em_storage_alteration = 1;
+      per_info.control_regs.bits.storage_alt_space_ctl = 1;
+    }
+  else
+    {
+      per_info.control_regs.bits.em_storage_alteration = 0;
+      per_info.control_regs.bits.storage_alt_space_ctl = 0;
+    }
+  per_info.starting_addr = watch_lo_addr;
+  per_info.ending_addr = watch_hi_addr;
+  ptrace (PTRACE_POKEUSR_AREA, pid, &parea);
+}
+
+int
+s390_insert_watchpoint (int pid, CORE_ADDR addr, int len, int rw)
+{
+  CORE_ADDR hi_addr = addr + len - 1;
+  watch_area *newarea = (watch_area *) malloc (sizeof (watch_area));
+
+
+  if (newarea)
+    {
+      newarea->next = watch_base;
+      watch_base = newarea;
+      watch_lo_addr = min (watch_lo_addr, addr);
+      watch_hi_addr = max (watch_hi_addr, hi_addr);
+      newarea->lo_addr = addr;
+      newarea->hi_addr = hi_addr;
+      if (watch_area_cnt == 0)
+	{
+	  watch_lo_addr = newarea->lo_addr;
+	  watch_hi_addr = newarea->hi_addr;
+	}
+      watch_area_cnt++;
+      s390_fix_watch_points (pid);
+    }
+  return newarea ? 0 : -1;
+}
+
+
+int
+s390_remove_watchpoint (int pid, CORE_ADDR addr, int len)
+{
+  watch_area *curr = watch_base, *prev, *matchCurr;
+  CORE_ADDR hi_addr = addr + len - 1;
+  CORE_ADDR watch_second_lo_addr = 0xffffffffUL, watch_second_hi_addr = 0;
+  int lo_addr_ref_cnt, hi_addr_ref_cnt;
+  prev = matchCurr = NULL;
+  lo_addr_ref_cnt = (addr == watch_lo_addr);
+  hi_addr_ref_cnt = (addr == watch_hi_addr);
+  while (curr)
+    {
+      if (matchCurr == NULL)
+	{
+	  if (curr->lo_addr == addr && curr->hi_addr == hi_addr)
+	    {
+	      matchCurr = curr;
+	      if (prev)
+		prev->next = curr->next;
+	      else
+		watch_base = curr->next;
+	    }
+	  prev = curr;
+	}
+      if (lo_addr_ref_cnt)
+	{
+	  if (watch_lo_addr == curr->lo_addr)
+	    lo_addr_ref_cnt++;
+	  if (curr->lo_addr > watch_lo_addr &&
+	      curr->lo_addr < watch_second_lo_addr)
+	    watch_second_lo_addr = curr->lo_addr;
+	}
+      if (hi_addr_ref_cnt)
+	{
+	  if (watch_hi_addr == curr->hi_addr)
+	    hi_addr_ref_cnt++;
+	  if (curr->hi_addr < watch_hi_addr &&
+	      curr->hi_addr > watch_second_hi_addr)
+	    watch_second_hi_addr = curr->hi_addr;
+	}
+      curr = curr->next;
+    }
+  if (matchCurr)
+    {
+      free (matchCurr);
+      watch_area_cnt--;
+      if (watch_area_cnt)
+	{
+	  if (lo_addr_ref_cnt == 2)
+	    watch_lo_addr = watch_second_lo_addr;
+	  if (hi_addr_ref_cnt == 2)
+	    watch_hi_addr = watch_second_hi_addr;
+	}
+      else
+	{
+	  watch_lo_addr = watch_hi_addr = 0;
+	}
+      s390_fix_watch_points (pid);
+      return 0;
+    }
+  else
+    {
+      fprintf_unfiltered (gdb_stderr,
+			  "Attempt to remove nonexistent watchpoint in s390_remove_watchpoint\n");
+      return -1;
+    }
+}
+
+int
+kernel_u_size (void)
+{
+  return sizeof (struct user);
+}
+
+
+#if  (defined (S390_FP0_REGNUM) && defined (HAVE_FPREGSET_T) && defined(HAVE_SYS_PROCFS_H) && defined (HAVE_GREGSET_T))
+void
+supply_gregset (gregset_t * gregsetp)
+{
+  int regi;
+  greg_t *gregp = (greg_t *) gregsetp;
+
+  supply_register (S390_PSWM_REGNUM, (char *) &gregp[S390_PSWM_REGNUM]);
+  supply_register (S390_PC_REGNUM, (char *) &gregp[S390_PC_REGNUM]);
+  for (regi = 0; regi < S390_NUM_GPRS; regi++)
+    supply_register (S390_GP0_REGNUM + regi,
+		     (char *) &gregp[S390_GP0_REGNUM + regi]);
+  for (regi = 0; regi < S390_NUM_ACRS; regi++)
+    supply_register (S390_FIRST_ACR + regi,
+		     (char *) &gregp[S390_FIRST_ACR + regi]);
+  /* unfortunately this isn't in gregsetp */
+  for (regi = 0; regi < S390_NUM_CRS; regi++)
+    supply_register (S390_FIRST_CR + regi, NULL);
+}
+
+
+void
+supply_fpregset (fpregset_t * fpregsetp)
+{
+  int regi;
+
+  supply_register (S390_FPC_REGNUM, (char *) &fpregsetp->fpc);
+  for (regi = 0; regi < S390_NUM_FPRS; regi++)
+    supply_register (S390_FP0_REGNUM + regi, (char *) &fpregsetp->fprs[regi]);
+
+}
+
+void
+fill_gregset (gregset_t * gregsetp, int regno)
+{
+  greg_t *gregp = (greg_t *) gregsetp;
+
+  if (regno >= S390_FIRST_CR && regno <= S390_LAST_CR)
+    supply_register (regno, NULL);
+  else if (regno != -1)
+    supply_register (regno, (char *) &gregp[regno]);
+  else
+    supply_gregset (gregsetp);
+}
+
+/*  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 (fpregset_t * fpregsetp, int regno)
+{
+  if (regno == -1)
+    supply_fpregset (fpregsetp);
+  else
+    supply_register (regno,
+		     &((char *) fpregsetp)[REGISTER_BYTE (regno) -
+					   REGISTER_BYTE (S390_FPC_REGNUM)]);
+}
+
+
+#else
+#error "There are a few possibilities here"
+#error "1) You aren't compiling for linux & don't need a core dumps to work."
+#error "2) The header files sys/elf.h sys/user.h sys/ptrace.h & sys/procfs.h"
+#error "libc files are inconsistent with linux/include/asm-s390/"
+#error "3) you didn't do a completely clean build & delete config.cache."
+#endif
+#endif /* GDBSERVER */
diff --git a/gdb/s390-tdep.c b/gdb/s390-tdep.c
new file mode 100644
index 0000000..1590268
--- /dev/null
+++ b/gdb/s390-tdep.c
@@ -0,0 +1,1504 @@
+/* Target-dependent code for GDB, the GNU debugger.
+   Copyright 2001 Free Software Foundation, Inc.
+   Contributed by D.J. Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
+   for IBM Deutschland Entwicklung GmbH, IBM Corporation.
+
+   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.  */
+
+#define S390_TDEP		/* for special macros in tm-s390.h */
+#include <defs.h>
+#include "arch-utils.h"
+#include "frame.h"
+#include "inferior.h"
+#include "symtab.h"
+#include "target.h"
+#include "gdbcore.h"
+#include "gdbcmd.h"
+#include "symfile.h"
+#include "objfiles.h"
+#include "tm.h"
+#include "../bfd/bfd.h"
+#include "floatformat.h"
+#include "regcache.h"
+
+
+
+
+
+/* Number of bytes of storage in the actual machine representation
+   for register N. 
+   Note that the unsigned cast here forces the result of the
+   subtraction to very high positive values if N < S390_FP0_REGNUM */
+int
+s390_register_raw_size (int reg_nr)
+{
+  return ((unsigned) reg_nr - S390_FP0_REGNUM) <
+    S390_NUM_FPRS ? S390_FPR_SIZE : 4;
+}
+
+int
+s390x_register_raw_size (int reg_nr)
+{
+  return (reg_nr == S390_FPC_REGNUM)
+    || (reg_nr >= S390_FIRST_ACR && reg_nr <= S390_LAST_ACR) ? 4 : 8;
+}
+
+int
+s390_cannot_fetch_register (int regno)
+{
+  return (regno >= S390_FIRST_CR && regno < (S390_FIRST_CR + 9)) ||
+    (regno >= (S390_FIRST_CR + 12) && regno <= S390_LAST_CR);
+}
+
+int
+s390_register_byte (int reg_nr)
+{
+  if (reg_nr <= S390_GP_LAST_REGNUM)
+    return reg_nr * S390_GPR_SIZE;
+  if (reg_nr <= S390_LAST_ACR)
+    return S390_ACR0_OFFSET + (((reg_nr) - S390_FIRST_ACR) * S390_ACR_SIZE);
+  if (reg_nr <= S390_LAST_CR)
+    return S390_CR0_OFFSET + (((reg_nr) - S390_FIRST_CR) * S390_CR_SIZE);
+  if (reg_nr == S390_FPC_REGNUM)
+    return S390_FPC_OFFSET;
+  else
+    return S390_FP0_OFFSET + (((reg_nr) - S390_FP0_REGNUM) * S390_FPR_SIZE);
+}
+
+#ifndef GDBSERVER
+#define S390_MAX_INSTR_SIZE (6)
+#define S390_SYSCALL_OPCODE (0x0a)
+#define S390_SYSCALL_SIZE   (2)
+#define S390_SIGCONTEXT_SREGS_OFFSET (8)
+#define S390X_SIGCONTEXT_SREGS_OFFSET (8)
+#define S390_SIGREGS_FP0_OFFSET       (144)
+#define S390X_SIGREGS_FP0_OFFSET      (216)
+#define S390_UC_MCONTEXT_OFFSET    (256)
+#define S390X_UC_MCONTEXT_OFFSET   (344)
+#define S390_STACK_FRAME_OVERHEAD  (GDB_TARGET_IS_ESAME ? 160:96)
+#define S390_SIGNAL_FRAMESIZE  (GDB_TARGET_IS_ESAME ? 160:96)
+#define s390_NR_sigreturn          119
+#define s390_NR_rt_sigreturn       173
+
+
+
+struct frame_extra_info
+{
+  int initialised;
+  int good_prologue;
+  CORE_ADDR function_start;
+  CORE_ADDR skip_prologue_function_start;
+  CORE_ADDR saved_pc_valid;
+  CORE_ADDR saved_pc;
+  CORE_ADDR sig_fixed_saved_pc_valid;
+  CORE_ADDR sig_fixed_saved_pc;
+  CORE_ADDR frame_pointer_saved_pc;	/* frame pointer needed for alloca */
+  CORE_ADDR stack_bought;	/* amount we decrement the stack pointer by */
+  CORE_ADDR sigcontext;
+};
+
+
+static CORE_ADDR s390_frame_saved_pc_nofix (struct frame_info *fi);
+
+int
+s390_readinstruction (bfd_byte instr[], CORE_ADDR at,
+		      struct disassemble_info *info)
+{
+  int instrlen;
+
+  static int s390_instrlen[] = {
+    2,
+    4,
+    4,
+    6
+  };
+  if ((*info->read_memory_func) (at, &instr[0], 2, info))
+    return -1;
+  instrlen = s390_instrlen[instr[0] >> 6];
+  if ((*info->read_memory_func) (at + 2, &instr[2], instrlen - 2, info))
+    return -1;
+  return instrlen;
+}
+
+static void
+s390_memset_extra_info (struct frame_extra_info *fextra_info)
+{
+  memset (fextra_info, 0, sizeof (struct frame_extra_info));
+}
+
+
+
+char *
+s390_register_name (int reg_nr)
+{
+  static char *register_names[] = {
+    "pswm", "pswa",
+    "gpr0", "gpr1", "gpr2", "gpr3", "gpr4", "gpr5", "gpr6", "gpr7",
+    "gpr8", "gpr9", "gpr10", "gpr11", "gpr12", "gpr13", "gpr14", "gpr15",
+    "acr0", "acr1", "acr2", "acr3", "acr4", "acr5", "acr6", "acr7",
+    "acr8", "acr9", "acr10", "acr11", "acr12", "acr13", "acr14", "acr15",
+    "cr0", "cr1", "cr2", "cr3", "cr4", "cr5", "cr6", "cr7",
+    "cr8", "cr9", "cr10", "cr11", "cr12", "cr13", "cr14", "cr15",
+    "fpc",
+    "fpr0", "fpr1", "fpr2", "fpr3", "fpr4", "fpr5", "fpr6", "fpr7",
+    "fpr8", "fpr9", "fpr10", "fpr11", "fpr12", "fpr13", "fpr14", "fpr15"
+  };
+
+  if (reg_nr >= S390_LAST_REGNUM)
+    return NULL;
+  return register_names[reg_nr];
+}
+
+
+
+
+int
+s390_stab_reg_to_regnum (int regno)
+{
+  return regno >= 64 ? S390_PSWM_REGNUM - 64 :
+    regno >= 48 ? S390_FIRST_ACR - 48 :
+    regno >= 32 ? S390_FIRST_CR - 32 :
+    regno <= 15 ? (regno + 2) :
+    S390_FP0_REGNUM + ((regno - 16) & 8) + (((regno - 16) & 3) << 1) +
+    (((regno - 16) & 4) >> 2);
+}
+
+
+
+/* s390_get_frame_info based on Hartmuts
+   prologue definition in
+   gcc-2.8.1/config/l390/linux.c 
+
+   It reads one instruction at a time & based on whether
+   it looks like prologue code or not it makes a decision on
+   whether the prologue is over, there are various state machines
+   in the code to determine if the prologue code is possilby valid.
+   
+   This is done to hopefully allow the code survive minor revs of
+   calling conventions.
+
+ */
+
+int
+s390_get_frame_info (CORE_ADDR pc, struct frame_extra_info *fextra_info,
+		     struct frame_info *fi, int init_extra_info)
+{
+#define CONST_POOL_REGIDX 13
+#define GOT_REGIDX        12
+  bfd_byte instr[S390_MAX_INSTR_SIZE];
+  CORE_ADDR test_pc = pc, test_pc2;
+  CORE_ADDR orig_sp = 0, save_reg_addr = 0, *saved_regs = NULL;
+  int valid_prologue, good_prologue = 0;
+  int gprs_saved[S390_NUM_GPRS];
+  int fprs_saved[S390_NUM_FPRS];
+  int regidx, instrlen;
+  int save_link_regidx, subtract_sp_regidx;
+  int const_pool_state, save_link_state, got_state;
+  int frame_pointer_found, varargs_state;
+  int loop_cnt, gdb_gpr_store, gdb_fpr_store;
+  int frame_pointer_regidx = 0xf;
+  int offset, expected_offset;
+  int err = 0;
+  disassemble_info info;
+  const_pool_state = save_link_state = got_state = varargs_state = 0;
+  frame_pointer_found = 0;
+  memset (gprs_saved, 0, sizeof (gprs_saved));
+  memset (fprs_saved, 0, sizeof (fprs_saved));
+  info.read_memory_func = dis_asm_read_memory;
+
+  save_link_regidx = subtract_sp_regidx = 0;
+  if (fextra_info)
+    {
+      if (fi && fi->frame)
+	{
+	  orig_sp = fi->frame + fextra_info->stack_bought;
+	  saved_regs = fi->saved_regs;
+	}
+      if (init_extra_info || !fextra_info->initialised)
+	{
+	  s390_memset_extra_info (fextra_info);
+	  fextra_info->function_start = pc;
+	  fextra_info->initialised = 1;
+	}
+    }
+  instrlen = 0;
+  do
+    {
+      valid_prologue = 0;
+      test_pc += instrlen;
+      /* add the previous instruction len */
+      instrlen = s390_readinstruction (instr, test_pc, &info);
+      if (instrlen < 0)
+	{
+	  good_prologue = 0;
+	  err = -1;
+	  break;
+	}
+      /* We probably are in a glibc syscall */
+      if (instr[0] == S390_SYSCALL_OPCODE && test_pc == pc)
+	{
+	  good_prologue = 1;
+	  if (saved_regs && fextra_info && fi->next && fi->next->extra_info
+	      && fi->next->extra_info->sigcontext)
+	    {
+	      /* We are backtracing from a signal handler */
+	      save_reg_addr = fi->next->extra_info->sigcontext +
+		REGISTER_BYTE (S390_GP0_REGNUM);
+	      for (regidx = 0; regidx < S390_NUM_GPRS; regidx++)
+		{
+		  saved_regs[S390_GP0_REGNUM + regidx] = save_reg_addr;
+		  save_reg_addr += S390_GPR_SIZE;
+		}
+	      save_reg_addr = fi->next->extra_info->sigcontext +
+		(GDB_TARGET_IS_ESAME ? S390X_SIGREGS_FP0_OFFSET :
+		 S390_SIGREGS_FP0_OFFSET);
+	      for (regidx = 0; regidx < S390_NUM_FPRS; regidx++)
+		{
+		  saved_regs[S390_FP0_REGNUM + regidx] = save_reg_addr;
+		  save_reg_addr += S390_FPR_SIZE;
+		}
+	    }
+	  break;
+	}
+      if (save_link_state == 0)
+	{
+	  /* check for a stack relative STMG or STM */
+	  if (((GDB_TARGET_IS_ESAME &&
+		((instr[0] == 0xeb) && (instr[5] == 0x24))) ||
+	       (instr[0] == 0x90)) && ((instr[2] >> 4) == 0xf))
+	    {
+	      regidx = (instr[1] >> 4);
+	      if (regidx < 6)
+		varargs_state = 1;
+	      offset = ((instr[2] & 0xf) << 8) + instr[3];
+	      expected_offset =
+		S390_GPR6_STACK_OFFSET + (S390_GPR_SIZE * (regidx - 6));
+	      if (offset != expected_offset)
+		{
+		  good_prologue = 0;
+		  break;
+		}
+	      if (saved_regs)
+		save_reg_addr = orig_sp + offset;
+	      for (; regidx <= (instr[1] & 0xf); regidx++)
+		{
+		  if (gprs_saved[regidx])
+		    {
+		      good_prologue = 0;
+		      break;
+		    }
+		  good_prologue = 1;
+		  gprs_saved[regidx] = 1;
+		  if (saved_regs)
+		    {
+		      saved_regs[S390_GP0_REGNUM + regidx] = save_reg_addr;
+		      save_reg_addr += S390_GPR_SIZE;
+		    }
+		}
+	      valid_prologue = 1;
+	      continue;
+	    }
+	}
+      /* check for a stack relative STG or ST */
+      if ((save_link_state == 0 || save_link_state == 3) &&
+	  ((GDB_TARGET_IS_ESAME &&
+	    ((instr[0] == 0xe3) && (instr[5] == 0x24))) ||
+	   (instr[0] == 0x50)) && ((instr[2] >> 4) == 0xf))
+	{
+	  regidx = instr[1] >> 4;
+	  offset = ((instr[2] & 0xf) << 8) + instr[3];
+	  if (offset == 0)
+	    {
+	      if (save_link_state == 3 && regidx == save_link_regidx)
+		{
+		  save_link_state = 4;
+		  valid_prologue = 1;
+		  continue;
+		}
+	      else
+		break;
+	    }
+	  if (regidx < 6)
+	    varargs_state = 1;
+	  expected_offset =
+	    S390_GPR6_STACK_OFFSET + (S390_GPR_SIZE * (regidx - 6));
+	  if (offset != expected_offset)
+	    {
+	      good_prologue = 0;
+	      break;
+	    }
+	  if (gprs_saved[regidx])
+	    {
+	      good_prologue = 0;
+	      break;
+	    }
+	  good_prologue = 1;
+	  gprs_saved[regidx] = 1;
+	  if (saved_regs)
+	    {
+	      save_reg_addr = orig_sp + offset;
+	      saved_regs[S390_GP0_REGNUM + regidx] = save_reg_addr;
+	    }
+	  valid_prologue = 1;
+	  continue;
+	}
+
+      /* check for STD */
+      if (instr[0] == 0x60 && (instr[2] >> 4) == 0xf)
+	{
+	  regidx = instr[1] >> 4;
+	  if (regidx == 0 || regidx == 2)
+	    varargs_state = 1;
+	  if (fprs_saved[regidx])
+	    {
+	      good_prologue = 0;
+	      break;
+	    }
+	  fprs_saved[regidx] = 1;
+	  if (saved_regs)
+	    {
+	      save_reg_addr = orig_sp + (((instr[2] & 0xf) << 8) + instr[3]);
+	      saved_regs[S390_FP0_REGNUM + regidx] = save_reg_addr;
+	    }
+	  valid_prologue = 1;
+	  continue;
+	}
+
+
+      if (const_pool_state == 0)
+	{
+
+	  if (GDB_TARGET_IS_ESAME)
+	    {
+	      /* Check for larl CONST_POOL_REGIDX,offset on ESAME */
+	      if ((instr[0] == 0xc0)
+		  && (instr[1] == (CONST_POOL_REGIDX << 4)))
+		{
+		  const_pool_state = 2;
+		  valid_prologue = 1;
+		  continue;
+		}
+	    }
+	  else
+	    {
+	      /* Check for BASR gpr13,gpr0 used to load constant pool pointer to r13 in old compiler */
+	      if (instr[0] == 0xd && (instr[1] & 0xf) == 0
+		  && ((instr[1] >> 4) == CONST_POOL_REGIDX))
+		{
+		  const_pool_state = 1;
+		  valid_prologue = 1;
+		  continue;
+		}
+	    }
+	  /* Check for new fangled bras %r13,newpc to load new constant pool */
+	  /* embedded in code, older pre abi compilers also emitted this stuff.  */
+	  if ((instr[0] == 0xa7) && ((instr[1] & 0xf) == 0x5) &&
+	      ((instr[1] >> 4) == CONST_POOL_REGIDX)
+	      && ((instr[2] & 0x80) == 0))
+	    {
+	      const_pool_state = 2;
+	      test_pc +=
+		(((((instr[2] & 0xf) << 8) + instr[3]) << 1) - instrlen);
+	      valid_prologue = 1;
+	      continue;
+	    }
+	}
+      /* Check for AGHI or AHI CONST_POOL_REGIDX,val */
+      if (const_pool_state == 1 && (instr[0] == 0xa7) &&
+	  ((GDB_TARGET_IS_ESAME &&
+	    (instr[1] == ((CONST_POOL_REGIDX << 4) | 0xb))) ||
+	   (instr[1] == ((CONST_POOL_REGIDX << 4) | 0xa))))
+	{
+	  const_pool_state = 2;
+	  valid_prologue = 1;
+	  continue;
+	}
+      /* Check for LGR or LR gprx,15 */
+      if ((GDB_TARGET_IS_ESAME &&
+	   instr[0] == 0xb9 && instr[1] == 0x04 && (instr[3] & 0xf) == 0xf) ||
+	  (instr[0] == 0x18 && (instr[1] & 0xf) == 0xf))
+	{
+	  if (GDB_TARGET_IS_ESAME)
+	    regidx = instr[3] >> 4;
+	  else
+	    regidx = instr[1] >> 4;
+	  if (save_link_state == 0 && regidx != 0xb)
+	    {
+	      /* Almost defintely code for
+	         decrementing the stack pointer 
+	         ( i.e. a non leaf function 
+	         or else leaf with locals ) */
+	      save_link_regidx = regidx;
+	      save_link_state = 1;
+	      valid_prologue = 1;
+	      continue;
+	    }
+	  /* We use this frame pointer for alloca
+	     unfortunately we need to assume its gpr11
+	     otherwise we would need a smarter prologue
+	     walker. */
+	  if (!frame_pointer_found && regidx == 0xb)
+	    {
+	      frame_pointer_regidx = 0xb;
+	      frame_pointer_found = 1;
+	      if (fextra_info)
+		fextra_info->frame_pointer_saved_pc = test_pc;
+	      valid_prologue = 1;
+	      continue;
+	    }
+	}
+      /* Check for AHI or AGHI gpr15,val */
+      if (save_link_state == 1 && (instr[0] == 0xa7) &&
+	  ((GDB_TARGET_IS_ESAME && (instr[1] == 0xfb)) || (instr[1] == 0xfa)))
+	{
+	  if (fextra_info)
+	    fextra_info->stack_bought =
+	      -extract_signed_integer (&instr[2], 2);
+	  save_link_state = 3;
+	  valid_prologue = 1;
+	  continue;
+	}
+      /* Alternatively check for the complex construction for
+         buying more than 32k of stack
+         BRAS gprx,.+8
+         long vals    %r15,0(%gprx)  gprx currently r1 */
+      if ((save_link_state == 1) && (instr[0] == 0xa7)
+	  && ((instr[1] & 0xf) == 0x5) && (instr[2] == 0)
+	  && (instr[3] == 0x4) && ((instr[1] >> 4) != CONST_POOL_REGIDX))
+	{
+	  subtract_sp_regidx = instr[1] >> 4;
+	  save_link_state = 2;
+	  if (fextra_info)
+	    target_read_memory (test_pc + instrlen,
+				(char *) &fextra_info->stack_bought,
+				sizeof (fextra_info->stack_bought));
+	  test_pc += 4;
+	  valid_prologue = 1;
+	  continue;
+	}
+      if (save_link_state == 2 && instr[0] == 0x5b
+	  && instr[1] == 0xf0 &&
+	  instr[2] == (subtract_sp_regidx << 4) && instr[3] == 0)
+	{
+	  save_link_state = 3;
+	  valid_prologue = 1;
+	  continue;
+	}
+      /* check for LA gprx,offset(15) used for varargs */
+      if ((instr[0] == 0x41) && ((instr[2] >> 4) == 0xf) &&
+	  ((instr[1] & 0xf) == 0))
+	{
+	  /* some code uses gpr7 to point to outgoing args */
+	  if (((instr[1] >> 4) == 7) && (save_link_state == 0) &&
+	      ((instr[2] & 0xf) == 0)
+	      && (instr[3] == S390_STACK_FRAME_OVERHEAD))
+	    {
+	      valid_prologue = 1;
+	      continue;
+	    }
+	  if (varargs_state == 1)
+	    {
+	      varargs_state = 2;
+	      valid_prologue = 1;
+	      continue;
+	    }
+	}
+      /* Check for a GOT load */
+
+      if (GDB_TARGET_IS_ESAME)
+	{
+	  /* Check for larl  GOT_REGIDX, on ESAME */
+	  if ((got_state == 0) && (instr[0] == 0xc0)
+	      && (instr[1] == (GOT_REGIDX << 4)))
+	    {
+	      got_state = 2;
+	      valid_prologue = 1;
+	      continue;
+	    }
+	}
+      else
+	{
+	  /* check for l GOT_REGIDX,x(CONST_POOL_REGIDX) */
+	  if (got_state == 0 && const_pool_state == 2 && instr[0] == 0x58
+	      && (instr[2] == (CONST_POOL_REGIDX << 4))
+	      && ((instr[1] >> 4) == GOT_REGIDX))
+	    {
+	      got_state == 1;
+	      valid_prologue = 1;
+	      continue;
+	    }
+	  /* Check for subsequent ar got_regidx,basr_regidx */
+	  if (got_state == 1 && instr[0] == 0x1a &&
+	      instr[1] == ((GOT_REGIDX << 4) | CONST_POOL_REGIDX))
+	    {
+	      got_state = 2;
+	      valid_prologue = 1;
+	      continue;
+	    }
+	}
+    }
+  while (valid_prologue && good_prologue);
+  if (good_prologue)
+    {
+      good_prologue = (((got_state == 0) || (got_state == 2)) &&
+		       ((const_pool_state == 0) || (const_pool_state == 2)) &&
+		       ((save_link_state == 0) || (save_link_state == 4)) &&
+		       ((varargs_state == 0) || (varargs_state == 2)));
+    }
+  if (fextra_info)
+    {
+      fextra_info->good_prologue = good_prologue;
+      fextra_info->skip_prologue_function_start =
+	(good_prologue ? test_pc : pc);
+    }
+  return err;
+}
+
+
+int
+s390_check_function_end (CORE_ADDR pc)
+{
+  bfd_byte instr[S390_MAX_INSTR_SIZE];
+  disassemble_info info;
+  int regidx, instrlen;
+
+  info.read_memory_func = dis_asm_read_memory;
+  instrlen = s390_readinstruction (instr, pc, &info);
+  if (instrlen < 0)
+    return -1;
+  /* check for BR */
+  if (instrlen != 2 || instr[0] != 07 || (instr[1] >> 4) != 0xf)
+    return 0;
+  regidx = instr[1] & 0xf;
+  /* Check for LMG or LG */
+  instrlen =
+    s390_readinstruction (instr, pc - (GDB_TARGET_IS_ESAME ? 6 : 4), &info);
+  if (instrlen < 0)
+    return -1;
+  if (GDB_TARGET_IS_ESAME)
+    {
+
+      if (instrlen != 6 || instr[0] != 0xeb || instr[5] != 0x4)
+	return 0;
+    }
+  else if (instrlen != 4 || instr[0] != 0x98)
+    {
+      return 0;
+    }
+  if ((instr[2] >> 4) != 0xf)
+    return 0;
+  if (regidx == 14)
+    return 1;
+  instrlen = s390_readinstruction (instr, pc - (GDB_TARGET_IS_ESAME ? 12 : 8),
+				   &info);
+  if (instrlen < 0)
+    return -1;
+  if (GDB_TARGET_IS_ESAME)
+    {
+      /* Check for LG */
+      if (instrlen != 6 || instr[0] != 0xe3 || instr[5] != 0x4)
+	return 0;
+    }
+  else
+    {
+      /* Check for L */
+      if (instrlen != 4 || instr[0] != 0x58)
+	return 0;
+    }
+  if (instr[2] >> 4 != 0xf)
+    return 0;
+  if (instr[1] >> 4 != regidx)
+    return 0;
+  return 1;
+}
+
+static CORE_ADDR
+s390_sniff_pc_function_start (CORE_ADDR pc, struct frame_info *fi)
+{
+  CORE_ADDR function_start, test_function_start;
+  int loop_cnt, err, function_end;
+  struct frame_extra_info fextra_info;
+  function_start = get_pc_function_start (pc);
+
+  if (function_start == 0)
+    {
+      test_function_start = pc;
+      if (test_function_start & 1)
+	return 0;		/* This has to be bogus */
+      loop_cnt = 0;
+      do
+	{
+
+	  err =
+	    s390_get_frame_info (test_function_start, &fextra_info, fi, 1);
+	  loop_cnt++;
+	  test_function_start -= 2;
+	  function_end = s390_check_function_end (test_function_start);
+	}
+      while (!(function_end == 1 || err || loop_cnt >= 4096 ||
+	       (fextra_info.good_prologue)));
+      if (fextra_info.good_prologue)
+	function_start = fextra_info.function_start;
+      else if (function_end == 1)
+	function_start = test_function_start;
+    }
+  return function_start;
+}
+
+
+
+CORE_ADDR
+s390_function_start (struct frame_info *fi)
+{
+  CORE_ADDR function_start = 0;
+
+  if (fi->extra_info && fi->extra_info->initialised)
+    function_start = fi->extra_info->function_start;
+  else if (fi->pc)
+    function_start = get_pc_function_start (fi->pc);
+  return function_start;
+}
+
+
+
+
+int
+s390_frameless_function_invocation (struct frame_info *fi)
+{
+  struct frame_extra_info fextra_info, *fextra_info_ptr;
+  int frameless = 0;
+
+  if (fi->next == NULL)		/* no may be frameless */
+    {
+      if (fi->extra_info)
+	fextra_info_ptr = fi->extra_info;
+      else
+	{
+	  fextra_info_ptr = &fextra_info;
+	  s390_get_frame_info (s390_sniff_pc_function_start (fi->pc, fi),
+			       fextra_info_ptr, fi, 1);
+	}
+      frameless = ((fextra_info_ptr->stack_bought == 0));
+    }
+  return frameless;
+
+}
+
+
+static int
+s390_is_sigreturn (CORE_ADDR pc, struct frame_info *sighandler_fi,
+		   CORE_ADDR *sregs, CORE_ADDR *sigcaller_pc)
+{
+  bfd_byte instr[S390_MAX_INSTR_SIZE];
+  disassemble_info info;
+  int instrlen;
+  CORE_ADDR scontext;
+  int retval = 0;
+  CORE_ADDR orig_sp;
+  CORE_ADDR temp_sregs;
+
+  scontext = temp_sregs = 0;
+
+  info.read_memory_func = dis_asm_read_memory;
+  instrlen = s390_readinstruction (instr, pc, &info);
+  if (sigcaller_pc)
+    *sigcaller_pc = 0;
+  if (((instrlen == S390_SYSCALL_SIZE) &&
+       (instr[0] == S390_SYSCALL_OPCODE)) &&
+      ((instr[1] == s390_NR_sigreturn) || (instr[1] == s390_NR_rt_sigreturn)))
+    {
+      if (sighandler_fi)
+	{
+	  if (s390_frameless_function_invocation (sighandler_fi))
+	    orig_sp = sighandler_fi->frame;
+	  else
+	    orig_sp = ADDR_BITS_REMOVE ((CORE_ADDR)
+					read_memory_integer (sighandler_fi->
+							     frame,
+							     S390_GPR_SIZE));
+	  if (orig_sp && sigcaller_pc)
+	    {
+	      scontext = orig_sp + S390_SIGNAL_FRAMESIZE;
+	      if (pc == scontext && instr[1] == s390_NR_rt_sigreturn)
+		{
+		  /* We got a new style rt_signal */
+		  /* get address of read ucontext->uc_mcontext */
+		  temp_sregs = orig_sp + (GDB_TARGET_IS_ESAME ?
+					  S390X_UC_MCONTEXT_OFFSET :
+					  S390_UC_MCONTEXT_OFFSET);
+		}
+	      else
+		{
+		  /* read sigcontext->sregs */
+		  temp_sregs = ADDR_BITS_REMOVE ((CORE_ADDR)
+						 read_memory_integer (scontext
+								      +
+								      (GDB_TARGET_IS_ESAME
+								       ?
+								       S390X_SIGCONTEXT_SREGS_OFFSET
+								       :
+								       S390_SIGCONTEXT_SREGS_OFFSET),
+								      S390_GPR_SIZE));
+
+		}
+	      /* read sigregs->psw.addr */
+	      *sigcaller_pc =
+		ADDR_BITS_REMOVE ((CORE_ADDR)
+				  read_memory_integer (temp_sregs +
+						       REGISTER_BYTE
+						       (S390_PC_REGNUM),
+						       S390_PSW_ADDR_SIZE));
+	    }
+	}
+      retval = 1;
+    }
+  if (sregs)
+    *sregs = temp_sregs;
+  return retval;
+}
+
+/*
+  We need to do something better here but this will keep us out of trouble
+  for the moment.
+  For some reason the blockframe.c calls us with fi->next->fromleaf
+  so this seems of little use to us. */
+void
+s390_init_frame_pc_first (int next_fromleaf, struct frame_info *fi)
+{
+  CORE_ADDR sigcaller_pc;
+
+  fi->pc = 0;
+  if (next_fromleaf)
+    {
+      fi->pc = ADDR_BITS_REMOVE (read_register (S390_RETADDR_REGNUM));
+      /* fix signal handlers */
+    }
+  else if (fi->next && fi->next->pc)
+    fi->pc = s390_frame_saved_pc_nofix (fi->next);
+  if (fi->pc && fi->next && fi->next->frame &&
+      s390_is_sigreturn (fi->pc, fi->next, NULL, &sigcaller_pc))
+    {
+      fi->pc = sigcaller_pc;
+    }
+
+}
+
+void
+s390_init_extra_frame_info (int fromleaf, struct frame_info *fi)
+{
+  fi->extra_info = frame_obstack_alloc (sizeof (struct frame_extra_info));
+  if (fi->pc)
+    s390_get_frame_info (s390_sniff_pc_function_start (fi->pc, fi),
+			 fi->extra_info, fi, 1);
+  else
+    s390_memset_extra_info (fi->extra_info);
+}
+
+/* If saved registers of frame FI are not known yet, read and cache them.
+   &FEXTRA_INFOP contains struct frame_extra_info; TDATAP can be NULL,
+   in which case the framedata are read.  */
+
+void
+s390_frame_init_saved_regs (struct frame_info *fi)
+{
+
+  int quick;
+
+  if (fi->saved_regs == NULL)
+    {
+      /* zalloc memsets the saved regs */
+      frame_saved_regs_zalloc (fi);
+      if (fi->pc)
+	{
+	  quick = (fi->extra_info && fi->extra_info->initialised
+		   && fi->extra_info->good_prologue);
+	  s390_get_frame_info (quick ? fi->extra_info->function_start :
+			       s390_sniff_pc_function_start (fi->pc, fi),
+			       fi->extra_info, fi, !quick);
+	}
+    }
+}
+
+
+
+CORE_ADDR
+s390_frame_args_address (struct frame_info *fi)
+{
+
+  /* Apparently gdb already knows gdb_args_offset itself */
+  return fi->frame;
+}
+
+
+static CORE_ADDR
+s390_frame_saved_pc_nofix (struct frame_info *fi)
+{
+  if (fi->extra_info && fi->extra_info->saved_pc_valid)
+    return fi->extra_info->saved_pc;
+  s390_frame_init_saved_regs (fi);
+  if (fi->extra_info)
+    {
+      fi->extra_info->saved_pc_valid = 1;
+      if (fi->extra_info->good_prologue)
+	{
+	  if (fi->saved_regs[S390_RETADDR_REGNUM])
+	    {
+	      return (fi->extra_info->saved_pc =
+		      ADDR_BITS_REMOVE (read_memory_integer
+					(fi->saved_regs[S390_RETADDR_REGNUM],
+					 S390_GPR_SIZE)));
+	    }
+	}
+    }
+  return 0;
+}
+
+CORE_ADDR
+s390_frame_saved_pc (struct frame_info *fi)
+{
+  CORE_ADDR saved_pc = 0, sig_pc;
+
+  if (fi->extra_info && fi->extra_info->sig_fixed_saved_pc_valid)
+    return fi->extra_info->sig_fixed_saved_pc;
+  saved_pc = s390_frame_saved_pc_nofix (fi);
+
+  if (fi->extra_info)
+    {
+      fi->extra_info->sig_fixed_saved_pc_valid = 1;
+      if (saved_pc)
+	{
+	  if (s390_is_sigreturn (saved_pc, fi, NULL, &sig_pc))
+	    saved_pc = sig_pc;
+	}
+      fi->extra_info->sig_fixed_saved_pc = saved_pc;
+    }
+  return saved_pc;
+}
+
+
+
+
+/* We want backtraces out of signal handlers so we don't
+   set thisframe->signal_handler_caller to 1 */
+
+CORE_ADDR
+s390_frame_chain (struct frame_info *thisframe)
+{
+  CORE_ADDR prev_fp = 0;
+
+  if (thisframe->prev && thisframe->prev->frame)
+    prev_fp = thisframe->prev->frame;
+  else
+    {
+      int sigreturn = 0;
+      CORE_ADDR sregs = 0;
+      struct frame_extra_info prev_fextra_info;
+
+      memset (&prev_fextra_info, 0, sizeof (prev_fextra_info));
+      if (thisframe->pc)
+	{
+	  CORE_ADDR saved_pc, sig_pc;
+
+	  saved_pc = s390_frame_saved_pc_nofix (thisframe);
+	  if (saved_pc)
+	    {
+	      if ((sigreturn =
+		   s390_is_sigreturn (saved_pc, thisframe, &sregs, &sig_pc)))
+		saved_pc = sig_pc;
+	      s390_get_frame_info (s390_sniff_pc_function_start
+				   (saved_pc, NULL), &prev_fextra_info, NULL,
+				   1);
+	    }
+	}
+      if (sigreturn)
+	{
+	  /* read sigregs,regs.gprs[11 or 15] */
+	  prev_fp = read_memory_integer (sregs +
+					 REGISTER_BYTE (S390_GP0_REGNUM +
+							(prev_fextra_info.
+							 frame_pointer_saved_pc
+							 ? 11 : 15)),
+					 S390_GPR_SIZE);
+	  thisframe->extra_info->sigcontext = sregs;
+	}
+      else
+	{
+	  if (thisframe->saved_regs)
+	    {
+
+	      int regno;
+
+	      regno =
+		((prev_fextra_info.frame_pointer_saved_pc
+		  && thisframe->
+		  saved_regs[S390_FRAME_REGNUM]) ? S390_FRAME_REGNUM :
+		 S390_SP_REGNUM);
+	      if (thisframe->saved_regs[regno])
+		prev_fp =
+		  read_memory_integer (thisframe->saved_regs[regno],
+				       S390_GPR_SIZE);
+	    }
+	}
+    }
+  return ADDR_BITS_REMOVE (prev_fp);
+}
+
+/*
+  Whether struct frame_extra_info is actually needed I'll have to figure
+  out as our frames are similar to rs6000 there is a possibility
+  i386 dosen't need it. */
+
+
+
+/* a given return value in `regbuf' with a type `valtype', extract and copy its
+   value into `valbuf' */
+void
+s390_extract_return_value (struct type *valtype, char *regbuf, char *valbuf)
+{
+  /* floats and doubles are returned in fpr0. fpr's have a size of 8 bytes.
+     We need to truncate the return value into float size (4 byte) if
+     necessary. */
+  int len = TYPE_LENGTH (valtype);
+
+  if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
+    {
+      if (len > (TARGET_FLOAT_BIT >> 3))
+	memcpy (valbuf, &regbuf[REGISTER_BYTE (S390_FP0_REGNUM)], len);
+      else
+	{
+	  /* float */
+	  DOUBLEST val;
+
+	  floatformat_to_doublest (&floatformat_ieee_double_big,
+				   &regbuf[REGISTER_BYTE (S390_FP0_REGNUM)],
+				   &val);
+	  store_floating (valbuf, len, val);
+	}
+    }
+  else
+    {
+      int offset = 0;
+      /* return value is copied starting from r2. */
+      if (TYPE_LENGTH (valtype) < S390_GPR_SIZE)
+	offset = S390_GPR_SIZE - TYPE_LENGTH (valtype);
+      memcpy (valbuf,
+	      regbuf + REGISTER_BYTE (S390_GP0_REGNUM + 2) + offset,
+	      TYPE_LENGTH (valtype));
+    }
+}
+
+
+static char *
+s390_promote_integer_argument (struct type *valtype, char *valbuf,
+			       char *reg_buff, int *arglen)
+{
+  char *value = valbuf;
+  int len = TYPE_LENGTH (valtype);
+
+  if (len < S390_GPR_SIZE)
+    {
+      /* We need to upgrade this value to a register to pass it correctly */
+      int idx, diff = S390_GPR_SIZE - len, negative =
+	(!TYPE_UNSIGNED (valtype) && value[0] & 0x80);
+      for (idx = 0; idx < S390_GPR_SIZE; idx++)
+	{
+	  reg_buff[idx] = (idx < diff ? (negative ? 0xff : 0x0) :
+			   value[idx - diff]);
+	}
+      value = reg_buff;
+      *arglen = S390_GPR_SIZE;
+    }
+  else
+    {
+      if (len & (S390_GPR_SIZE - 1))
+	{
+	  fprintf_unfiltered (gdb_stderr,
+			      "s390_promote_integer_argument detected an argument not "
+			      "a multiple of S390_GPR_SIZE & greater than S390_GPR_SIZE "
+			      "we might not deal with this correctly.\n");
+	}
+      *arglen = len;
+    }
+
+  return (value);
+}
+
+void
+s390_store_return_value (struct type *valtype, char *valbuf)
+{
+  int arglen;
+  char *reg_buff = alloca (max (S390_FPR_SIZE, REGISTER_SIZE)), *value;
+
+  if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
+    {
+      DOUBLEST tempfloat = extract_floating (valbuf, TYPE_LENGTH (valtype));
+
+      floatformat_from_doublest (&floatformat_ieee_double_big, &tempfloat,
+				 reg_buff);
+      write_register_bytes (REGISTER_BYTE (S390_FP0_REGNUM), reg_buff,
+			    S390_FPR_SIZE);
+    }
+  else
+    {
+      value =
+	s390_promote_integer_argument (valtype, valbuf, reg_buff, &arglen);
+      /* Everything else is returned in GPR2 and up. */
+      write_register_bytes (REGISTER_BYTE (S390_GP0_REGNUM + 2), value,
+			    arglen);
+    }
+}
+static int
+gdb_print_insn_s390 (bfd_vma memaddr, disassemble_info * info)
+{
+  bfd_byte instrbuff[S390_MAX_INSTR_SIZE];
+  int instrlen, cnt;
+
+  instrlen = s390_readinstruction (instrbuff, (CORE_ADDR) memaddr, info);
+  if (instrlen < 0)
+    {
+      (*info->memory_error_func) (instrlen, memaddr, info);
+      return -1;
+    }
+  for (cnt = 0; cnt < instrlen; cnt++)
+    info->fprintf_func (info->stream, "%02X ", instrbuff[cnt]);
+  for (cnt = instrlen; cnt < S390_MAX_INSTR_SIZE; cnt++)
+    info->fprintf_func (info->stream, "   ");
+  instrlen = print_insn_s390 (memaddr, info);
+  return instrlen;
+}
+
+
+
+/* Not the most efficent code in the world */
+int
+s390_fp_regnum ()
+{
+  int regno = S390_SP_REGNUM;
+  struct frame_extra_info fextra_info;
+
+  CORE_ADDR pc = ADDR_BITS_REMOVE (read_register (S390_PC_REGNUM));
+
+  s390_get_frame_info (s390_sniff_pc_function_start (pc, NULL), &fextra_info,
+		       NULL, 1);
+  if (fextra_info.frame_pointer_saved_pc)
+    regno = S390_FRAME_REGNUM;
+  return regno;
+}
+
+CORE_ADDR
+s390_read_fp ()
+{
+  return read_register (s390_fp_regnum ());
+}
+
+
+void
+s390_write_fp (CORE_ADDR val)
+{
+  write_register (s390_fp_regnum (), val);
+}
+
+
+void
+s390_push_dummy_frame ()
+{
+  CORE_ADDR orig_sp = read_register (S390_SP_REGNUM), new_sp;
+  void *saved_regs = alloca (REGISTER_BYTES);
+
+  new_sp = (orig_sp - (REGISTER_BYTES + S390_GPR_SIZE));
+  read_register_bytes (0, (char *) saved_regs, REGISTER_BYTES);
+  /* Use saved copy instead of orig_sp as this will have the correct endianness */
+  write_memory (new_sp, (char *) saved_regs + REGISTER_BYTE (S390_SP_REGNUM),
+		S390_GPR_SIZE);
+  write_memory (new_sp + S390_GPR_SIZE, (char *) &saved_regs, REGISTER_BYTES);
+  write_register (S390_SP_REGNUM, new_sp);
+}
+
+/* pop the innermost frame, go back to the caller.
+    Used in `call_function_by_hand' to remove an artificial stack
+     frame.  */
+void
+s390_pop_frame ()
+{
+  CORE_ADDR new_sp = read_register (S390_SP_REGNUM), orig_sp;
+  void *saved_regs = alloca (REGISTER_BYTES);
+
+
+  read_memory (new_sp + S390_GPR_SIZE, (char *) saved_regs, REGISTER_BYTES);
+  write_register_bytes (0, (char *) &saved_regs, REGISTER_BYTES);
+}
+
+/* used by call function by hand
+  struct_return indicates that this function returns a structure &
+  therefore gpr2 stores a pointer to the structure to be returned as
+  opposed to the first argument.
+  Currently I haven't seen a TYPE_CODE_INT whose size wasn't 2^n or less
+  than S390_GPR_SIZE this is good because I don't seem to have to worry
+  about sign extending pushed arguments (i.e. a signed char currently
+  comes into this code with a size of 4 ). */
+
+CORE_ADDR
+s390_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp,
+		     int struct_return, CORE_ADDR struct_addr)
+{
+  int num_float_args, num_gpr_args, orig_num_gpr_args, argno;
+  int second_pass, len, arglen, gprs_required;
+  CORE_ADDR outgoing_args_ptr, outgoing_args_space;
+  value_ptr arg;
+  struct type *type;
+  int max_num_gpr_args = 5 - (struct_return ? 1 : 0);
+  int arg0_regnum = S390_GP0_REGNUM + 2 + (struct_return ? 1 : 0);
+  char *reg_buff = alloca (max (S390_FPR_SIZE, REGISTER_SIZE)), *value;
+
+  for (second_pass = 0; second_pass <= 1; second_pass++)
+    {
+      if (second_pass)
+	outgoing_args_ptr = sp + S390_STACK_FRAME_OVERHEAD;
+      else
+	outgoing_args_ptr = 0;
+      num_float_args = 0;
+      num_gpr_args = 0;
+      for (argno = 0; argno < nargs; argno++)
+	{
+	  arg = args[argno];
+	  type = check_typedef (VALUE_TYPE (arg));
+	  len = TYPE_LENGTH (type);
+	  if (TYPE_CODE (type) == TYPE_CODE_FLT)
+	    {
+	      int all_float_registers_used =
+		num_float_args > (GDB_TARGET_IS_ESAME ? 3 : 1);
+
+	      if (second_pass)
+		{
+		  DOUBLEST tempfloat =
+		    extract_floating (VALUE_CONTENTS (arg), len);
+
+
+		  floatformat_from_doublest (all_float_registers_used &&
+					     len == (TARGET_FLOAT_BIT >> 3)
+					     ? &floatformat_ieee_single_big
+					     : &floatformat_ieee_double_big,
+					     &tempfloat, reg_buff);
+		  if (all_float_registers_used)
+		    write_memory (outgoing_args_ptr, reg_buff, len);
+		  else
+		    write_register_bytes (REGISTER_BYTE ((S390_FP0_REGNUM)
+							 +
+							 (2 *
+							  num_float_args)),
+					  reg_buff, S390_FPR_SIZE);
+		}
+	      if (all_float_registers_used)
+		outgoing_args_ptr += len;
+	      num_float_args++;
+	    }
+	  else
+	    {
+	      gprs_required = ((len + (S390_GPR_SIZE - 1)) / S390_GPR_SIZE);
+
+	      value =
+		s390_promote_integer_argument (type, VALUE_CONTENTS (arg),
+					       reg_buff, &arglen);
+
+	      orig_num_gpr_args = num_gpr_args;
+	      num_gpr_args += gprs_required;
+	      if (num_gpr_args > max_num_gpr_args)
+		{
+		  if (second_pass)
+		    write_memory (outgoing_args_ptr, value, arglen);
+		  outgoing_args_ptr += arglen;
+		}
+	      else
+		{
+		  if (second_pass)
+		    write_register_bytes (REGISTER_BYTE (arg0_regnum)
+					  +
+					  (orig_num_gpr_args * S390_GPR_SIZE),
+					  value, arglen);
+		}
+	    }
+	}
+      if (!second_pass)
+	{
+	  outgoing_args_space = outgoing_args_ptr;
+	  /* Align to 16 bytes because because I like alignment & 
+	     some of the kernel code requires 8 byte stack alignment at least. */
+	  sp = (sp - (S390_STACK_FRAME_OVERHEAD + outgoing_args_ptr)) & (-16);
+	}
+
+    }
+  return sp;
+
+}
+
+void
+s390_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
+		     struct value **args, struct type *value_type,
+		     int using_gcc)
+{
+  store_unsigned_integer (dummy + 4, REGISTER_SIZE, fun);
+}
+
+
+/* Return the GDB type object for the "standard" data type
+   of data in register N.  */
+struct type *
+s390_register_virtual_type (int regno)
+{
+  return ((unsigned) regno - S390_FPC_REGNUM) <
+    S390_NUM_FPRS ? builtin_type_double : builtin_type_int;
+}
+
+
+struct type *
+s390x_register_virtual_type (int regno)
+{
+  return (regno == S390_FPC_REGNUM) ||
+    (regno >= S390_FIRST_ACR && regno <= S390_LAST_ACR) ? builtin_type_int :
+    (regno >= S390_FP0_REGNUM) ? builtin_type_double : builtin_type_long;
+}
+
+
+
+void
+s390_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
+{
+  write_register (S390_GP0_REGNUM + 2, addr);
+}
+
+
+
+static unsigned char *
+s390_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr)
+{
+  static unsigned char breakpoint[] = { 0x0, 0x1 };
+
+  *lenptr = sizeof (breakpoint);
+  return breakpoint;
+}
+
+/* Advance PC across any function entry prologue instructions to reach some
+   "real" code.  */
+CORE_ADDR
+s390_skip_prologue (CORE_ADDR pc)
+{
+  struct frame_extra_info fextra_info;
+
+  s390_get_frame_info (pc, &fextra_info, NULL, 1);
+  return fextra_info.skip_prologue_function_start;
+}
+
+/* pc_in_call_dummy_on stack may work for us must test this */
+int
+s390_pc_in_call_dummy (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR frame_address)
+{
+  return pc > sp && pc < (sp + 4096);
+}
+
+/* Immediately after a function call, return the saved pc.
+   Can't go through the frames for this because on some machines
+   the new frame is not set up until the new function executes
+   some instructions.  */
+CORE_ADDR
+s390_saved_pc_after_call (struct frame_info *frame)
+{
+  return ADDR_BITS_REMOVE (read_register (S390_RETADDR_REGNUM));
+}
+
+static CORE_ADDR
+s390_addr_bits_remove (CORE_ADDR addr)
+{
+  return (addr) & 0x7fffffff;
+}
+
+
+static CORE_ADDR
+s390_push_return_address (CORE_ADDR pc, CORE_ADDR sp)
+{
+  return sp;
+}
+
+struct gdbarch *
+s390_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
+{
+
+  /* instruction sequence for s390 call dummy is as follows
+     bras %r1,.+8      ; 0xA7150004   
+     long basraddr     ; 0x00000000
+     l    %r1,0(%r1)   ; 0x58101000
+     basr %r14,%r1     ; 0x0DE1
+     breakpoint        ; 0x0001 */
+  static LONGEST s390_call_dummy_words[] = { 0xA7150004, 0x00000000,
+    0x58101000, 0x0DE10001
+  };
+  /* instruction sequence for esame call dummy is as follows
+     bras %r1,.+12     ; 0xA7150006   
+     long basraddr     ; 0x0000000000000000
+     lg   %r1,0(%r1)   ; 0xE31010000004
+     basr %r14,%r1     ; 0x0DE1
+     breakpoint        ; 0x0001 */
+  static LONGEST s390x_call_dummy_words[] = { 0xA715000600000000,
+    0x00000000E3101000,
+    0x00040DE100010000
+  };
+  struct gdbarch *gdbarch;
+  struct gdbarch_tdep *tdep;
+  int elf_flags;
+
+  /* First see if there is already a gdbarch that can satisfy the request.  */
+  arches = gdbarch_list_lookup_by_info (arches, &info);
+  if (arches != NULL)
+    return arches->gdbarch;
+
+  /* None found: is the request for a s390 architecture? */
+  if (info.bfd_arch_info->arch != bfd_arch_s390)
+    return NULL;		/* No; then it's not for us.  */
+
+  /* Yes: create a new gdbarch for the specified machine type.  */
+  gdbarch = gdbarch_alloc (&info, NULL);
+
+  set_gdbarch_believe_pcc_promotion (gdbarch, 0);
+
+  /* We don't define set_gdbarch_call_dummy_breakpoint_offset 
+     as we already have a breakpoint inserted. */
+  set_gdbarch_use_generic_dummy_frames (gdbarch, 0);
+
+  set_gdbarch_call_dummy_location (gdbarch, ON_STACK);
+  set_gdbarch_call_dummy_start_offset (gdbarch, 0);
+  set_gdbarch_pc_in_call_dummy (gdbarch, s390_pc_in_call_dummy);
+  set_gdbarch_frame_args_skip (gdbarch, 0);
+  set_gdbarch_frame_args_address (gdbarch, s390_frame_args_address);
+  set_gdbarch_frame_chain (gdbarch, s390_frame_chain);
+  set_gdbarch_frame_init_saved_regs (gdbarch, s390_frame_init_saved_regs);
+  set_gdbarch_frame_locals_address (gdbarch, s390_frame_args_address);
+  /* We can't do this */
+  set_gdbarch_frame_num_args (gdbarch, frame_num_args_unknown);
+  set_gdbarch_store_struct_return (gdbarch, s390_store_struct_return);
+  set_gdbarch_extract_return_value (gdbarch, s390_extract_return_value);
+  set_gdbarch_store_return_value (gdbarch, s390_store_return_value);
+  /* Amount PC must be decremented by after a breakpoint.
+     This is often the number of bytes in BREAKPOINT
+     but not always.  */
+  set_gdbarch_decr_pc_after_break (gdbarch, 2);
+  set_gdbarch_pop_frame (gdbarch, s390_pop_frame);
+  set_gdbarch_push_dummy_frame (gdbarch, s390_push_dummy_frame);
+  set_gdbarch_push_arguments (gdbarch, s390_push_arguments);
+  set_gdbarch_ieee_float (gdbarch, 1);
+  /* Stack grows downward.  */
+  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
+  /* Offset from address of function to start of its code.
+     Zero on most machines.  */
+  set_gdbarch_function_start_offset (gdbarch, 0);
+  set_gdbarch_max_register_raw_size (gdbarch, 8);
+  set_gdbarch_max_register_virtual_size (gdbarch, 8);
+  set_gdbarch_breakpoint_from_pc (gdbarch, s390_breakpoint_from_pc);
+  set_gdbarch_skip_prologue (gdbarch, s390_skip_prologue);
+  set_gdbarch_init_extra_frame_info (gdbarch, s390_init_extra_frame_info);
+  set_gdbarch_init_frame_pc_first (gdbarch, s390_init_frame_pc_first);
+  set_gdbarch_read_fp (gdbarch, s390_read_fp);
+  set_gdbarch_write_fp (gdbarch, s390_write_fp);
+  /* This function that tells us whether the function invocation represented
+     by FI does not have a frame on the stack associated with it.  If it
+     does not, FRAMELESS is set to 1, else 0.  */
+  set_gdbarch_frameless_function_invocation (gdbarch,
+					     s390_frameless_function_invocation);
+  /* Return saved PC from a frame */
+  set_gdbarch_frame_saved_pc (gdbarch, s390_frame_saved_pc);
+  /* FRAME_CHAIN takes a frame's nominal address
+     and produces the frame's chain-pointer. */
+  set_gdbarch_frame_chain (gdbarch, s390_frame_chain);
+  set_gdbarch_saved_pc_after_call (gdbarch, s390_saved_pc_after_call);
+  set_gdbarch_register_byte (gdbarch, s390_register_byte);
+  set_gdbarch_pc_regnum (gdbarch, S390_PC_REGNUM);
+  set_gdbarch_sp_regnum (gdbarch, S390_SP_REGNUM);
+  set_gdbarch_fp_regnum (gdbarch, S390_FP_REGNUM);
+  set_gdbarch_fp0_regnum (gdbarch, S390_FP0_REGNUM);
+  set_gdbarch_num_regs (gdbarch, S390_NUM_REGS);
+  set_gdbarch_cannot_fetch_register (gdbarch, s390_cannot_fetch_register);
+  set_gdbarch_cannot_store_register (gdbarch, s390_cannot_fetch_register);
+  set_gdbarch_get_saved_register (gdbarch, generic_get_saved_register);
+  set_gdbarch_use_struct_convention (gdbarch, generic_use_struct_convention);
+  set_gdbarch_frame_chain_valid (gdbarch, file_frame_chain_valid);
+  set_gdbarch_register_name (gdbarch, s390_register_name);
+  set_gdbarch_stab_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
+  set_gdbarch_dwarf_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
+  set_gdbarch_dwarf2_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
+  set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
+
+  /* Stuff below here wouldn't be required if gdbarch.sh was a little */
+  /* more intelligent */
+  set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 0);
+  set_gdbarch_call_dummy_p (gdbarch, 1);
+  set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
+  set_gdbarch_extract_struct_value_address (gdbarch, 0);
+  set_gdbarch_fix_call_dummy (gdbarch, s390_fix_call_dummy);
+#ifdef GDB_NM_FILE
+  set_gdbarch_prepare_to_proceed (gdbarch, linuxthreads_prepare_to_proceed);
+#endif
+  set_gdbarch_push_return_address (gdbarch, s390_push_return_address);
+
+  switch (info.bfd_arch_info->mach)
+    {
+    case bfd_mach_s390_esa:
+      set_gdbarch_register_size (gdbarch, 4);
+      set_gdbarch_call_dummy_length (gdbarch, 16);
+      set_gdbarch_register_raw_size (gdbarch, s390_register_raw_size);
+      set_gdbarch_register_virtual_size (gdbarch, s390_register_raw_size);
+      set_gdbarch_register_virtual_type (gdbarch, s390_register_virtual_type);
+
+      set_gdbarch_addr_bits_remove (gdbarch, s390_addr_bits_remove);
+
+      set_gdbarch_sizeof_call_dummy_words (gdbarch,
+					   sizeof (s390_call_dummy_words));
+      set_gdbarch_call_dummy_words (gdbarch, s390_call_dummy_words);
+      set_gdbarch_register_bytes (gdbarch, S390_REGISTER_BYTES);
+      break;
+    case bfd_mach_s390_esame:
+      set_gdbarch_register_size (gdbarch, 8);
+      set_gdbarch_call_dummy_length (gdbarch, 22);
+      set_gdbarch_register_raw_size (gdbarch, s390x_register_raw_size);
+      set_gdbarch_register_virtual_size (gdbarch, s390x_register_raw_size);
+      set_gdbarch_register_virtual_type (gdbarch,
+					 s390x_register_virtual_type);
+
+      set_gdbarch_long_bit (gdbarch, 64);
+      set_gdbarch_long_long_bit (gdbarch, 64);
+      set_gdbarch_ptr_bit (gdbarch, 64);
+      set_gdbarch_sizeof_call_dummy_words (gdbarch,
+					   sizeof (s390x_call_dummy_words));
+      set_gdbarch_call_dummy_words (gdbarch, s390x_call_dummy_words);
+      set_gdbarch_register_bytes (gdbarch, S390X_REGISTER_BYTES);
+      break;
+    }
+
+  return gdbarch;
+}
+
+
+
+void
+_initialize_s390_tdep ()
+{
+
+  /* Hook us into the gdbarch mechanism.  */
+  register_gdbarch_init (bfd_arch_s390, s390_gdbarch_init);
+  if (!tm_print_insn)		/* Someone may have already set it */
+    tm_print_insn = gdb_print_insn_s390;
+}
+
+#endif /* GDBSERVER */