Preliminary changes for ARM support on OpenBSD. "Can't hurt" espie@

2 files changed, 202 insertions, 0 deletions

diff --git a/gnu/usr.bin/gcc/gcc/config.gcc b/gnu/usr.bin/gcc/gcc/config.gcc
index 051f599b2de..0d5aea88643 100644
--- a/gnu/usr.bin/gcc/gcc/config.gcc
+++ b/gnu/usr.bin/gcc/gcc/config.gcc
@@ -694,6 +694,10 @@ arm*-*-netbsdelf*)
 	tm_file="dbxelf.h elfos.h netbsd.h netbsd-elf.h arm/elf.h arm/aout.h arm/arm.h arm/netbsd-elf.h"
 	tmake_file="${tmake_file} arm/t-netbsd"
 	;;
+arm*-*-openbsd*)
+	tm_file="dbxelf.h elfos.h arm/elf.h arm/aout.h arm/arm.h openbsd.h arm/openbsd.h"
+	tmake_file="${tmake_file} arm/t-netbsd"
+	;;
 arm*-*-netbsd*)
 	tm_file="arm/aout.h arm/arm.h netbsd.h netbsd-aout.h arm/netbsd.h"
 	tmake_file="t-netbsd arm/t-netbsd"
diff --git a/gnu/usr.bin/gcc/gcc/config/arm/openbsd.h b/gnu/usr.bin/gcc/gcc/config/arm/openbsd.h
new file mode 100644
index 00000000000..c850af5ddcb
--- /dev/null
+++ b/gnu/usr.bin/gcc/gcc/config/arm/openbsd.h
@@ -0,0 +1,198 @@
+/* Definitions of target machine for GNU compiler, NetBSD/arm ELF version.
+   Copyright (C) 2002 Free Software Foundation, Inc.
+   Contributed by Wasabi Systems, Inc.
+
+This file is part of GNU CC.
+
+GNU CC 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, or (at your option)
+any later version.
+
+GNU CC 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 GNU CC; see the file COPYING.  If not, write to
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+/* Run-time Target Specification.  */
+#undef TARGET_VERSION
+#define TARGET_VERSION fputs (" (OpenBSD/arm)", stderr);
+
+/* This is used in ASM_FILE_START.  */
+#undef ARM_OS_NAME
+#define ARM_OS_NAME "OpenBSD"
+
+/* Unsigned chars produces much better code than signed.  */
+#define DEFAULT_SIGNED_CHAR  0
+
+
+/* This defaults us to little-endian.  */
+#ifndef TARGET_ENDIAN_DEFAULT
+#define TARGET_ENDIAN_DEFAULT 0
+#endif
+
+#undef MULTILIB_DEFAULTS
+
+/* ARM6 family default cpu.  */
+#define SUBTARGET_CPU_DEFAULT TARGET_CPU_arm6
+
+/* Default is to use APCS-32 mode.  */
+
+/* Default it to use ATPCS with soft-VFP.  */
+#undef TARGET_DEFAULT
+#define TARGET_DEFAULT (ARM_FLAG_APCS_32 | ARM_FLAG_SOFT_FLOAT | ARM_FLAG_APCS_FRAME)
+
+#define TARGET_OS_CPP_BUILTINS()	\
+  do					\
+    {					\
+      OPENBSD_OS_CPP_BUILTINS_ELF();	\
+    }					\
+  while (0)
+
+#undef SUBTARGET_CPP_SPEC
+#define SUBTARGET_CPP_SPEC OBSD_CPP_SPEC
+
+/* Because TARGET_DEFAULT sets ARM_FLAG_APCS_32 */
+#undef CPP_APCS_PC_DEFAULT_SPEC
+#define CPP_APCS_PC_DEFAULT_SPEC "-D__APCS_32__"
+
+/* Because TARGET_DEFAULT sets ARM_FLAG_SOFT_FLOAT */
+#undef CPP_FLOAT_DEFAULT_SPEC
+#define CPP_FLOAT_DEFAULT_SPEC "-D__SOFTFP__"
+
+/* OBSD_LINK_SPEC appropriate for OpenBSD.  Support for GCC options 
+   -static, -assert, and -nostdlib.  */
+#undef OBSD_LINK_SPEC
+#ifdef OBSD_NO_DYNAMIC_LIBRARIES
+#define OBSD_LINK_SPEC \
+  "%{g:%{!nostdlib:-L/usr/lib/debug}} %{!nostdlib:%{!r*:%{!e*:-e start}}} -dc -dp %{assert*}"
+#else
+#define OBSD_LINK_SPEC \
+  "%{g:%{!nostdlib:-L/usr/lib/debug}} %{!shared:%{!nostdlib:%{!r*:%{!e*:-e start}}}} %{shared:-Bshareable -x} -dc -dp %{R*} %{static:-Bstatic} %{assert*}"
+#endif
+
+#undef SUBTARGET_EXTRA_SPECS
+#define SUBTARGET_EXTRA_SPECS				\
+  { "subtarget_extra_asm_spec",	SUBTARGET_EXTRA_ASM_SPEC }, \
+  { "subtarget_asm_float_spec", SUBTARGET_ASM_FLOAT_SPEC }, \
+  { "openbsd_link_spec",	OBSD_LINK_SPEC },	\
+  { "openbsd_entry_point",	OPENBSD_ENTRY_POINT },
+
+#define OPENBSD_ENTRY_POINT "__start"
+
+/* Pass -X to the linker so that it will strip symbols starting with 'L' */
+#undef LINK_SPEC
+#define LINK_SPEC \
+  "-X %{mbig-endian:-EB} %{mlittle-endian:-EL} \
+   %(openbsd_link_spec)"
+
+/* Make GCC agree with <machine/ansi.h>.  */
+
+#undef SIZE_TYPE
+#define SIZE_TYPE "unsigned int"
+
+#undef PTRDIFF_TYPE
+#define PTRDIFF_TYPE "int"
+
+/* We don't have any limit on the length as out debugger is GDB.  */
+#undef DBX_CONTIN_LENGTH
+
+/* NetBSD does its profiling differently to the Acorn compiler. We
+   don't need a word following the mcount call; and to skip it
+   requires either an assembly stub or use of fomit-frame-pointer when
+   compiling the profiling functions.  Since we break Acorn CC
+   compatibility below a little more won't hurt.  */
+   
+#undef ARM_FUNCTION_PROFILER                                  
+#define ARM_FUNCTION_PROFILER(STREAM,LABELNO)		\
+{							\
+  asm_fprintf (STREAM, "\tmov\t%Rip, %Rlr\n");		\
+  asm_fprintf (STREAM, "\tbl\t__mcount%s\n",		\
+	       NEED_PLT_RELOC ? "(PLT)" : "");		\
+}
+
+/* On the ARM `@' introduces a comment, so we must use something else
+   for .type directives.  */
+#undef TYPE_OPERAND_FMT
+#define TYPE_OPERAND_FMT "%%%s"
+
+/* NetBSD uses the old PCC style aggregate returning conventions. */
+#undef DEFAULT_PCC_STRUCT_RETURN
+#define DEFAULT_PCC_STRUCT_RETURN 1
+
+/* Although not normally relevant (since by default, all aggregates
+   are returned in memory) compiling some parts of libc requires
+   non-APCS style struct returns.  */
+#undef RETURN_IN_MEMORY
+
+
+/* VERY BIG NOTE: Change of structure alignment for NetBSD/arm.
+   There are consequences you should be aware of...
+
+   Normally GCC/arm uses a structure alignment of 32 for compatibility
+   with armcc.  This means that structures are padded to a word
+   boundary.  However this causes problems with bugged NetBSD kernel
+   code (possibly userland code as well - I have not checked every
+   binary).  The nature of this bugged code is to rely on sizeof()
+   returning the correct size of various structures rounded to the
+   nearest byte (SCSI and ether code are two examples, the vm system
+   is another).  This code breaks when the structure alignment is 32
+   as sizeof() will report a word=rounded size.  By changing the
+   structure alignment to 8. GCC will conform to what is expected by
+   NetBSD.
+   
+   This has several side effects that should be considered.
+   1. Structures will only be aligned to the size of the largest member.
+      i.e. structures containing only bytes will be byte aligned.
+	   structures containing shorts will be half word alinged.
+	   structures containing ints will be word aligned.
+
+      This means structures should be padded to a word boundary if
+      alignment of 32 is required for byte structures etc.
+
+   2. A potential performance penalty may exist if strings are no longer
+      word aligned.  GCC will not be able to use word load/stores to copy
+      short strings.
+
+   This modification is not encouraged but with the present state of the
+   NetBSD source tree it is currently the only solution that meets the
+   requirements.  */
+
+#undef DEFAULT_STRUCTURE_SIZE_BOUNDARY
+#define DEFAULT_STRUCTURE_SIZE_BOUNDARY 8
+
+/* Emit code to set up a trampoline and synchronize the caches.  */
+#undef INITIALIZE_TRAMPOLINE
+#define INITIALIZE_TRAMPOLINE(TRAMP, FNADDR, CXT)			\
+do									\
+  {									\
+    emit_move_insn (gen_rtx (MEM, SImode, plus_constant ((TRAMP), 8)),	\
+		    (CXT));						\
+    emit_move_insn (gen_rtx (MEM, SImode, plus_constant ((TRAMP), 12)),	\
+		    (FNADDR));						\
+    emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"),	\
+		       0, VOIDmode, 2, TRAMP, Pmode,			\
+		       plus_constant (TRAMP, TRAMPOLINE_SIZE), Pmode);	\
+  }									\
+while (0)
+
+/* Clear the instruction cache from `BEG' to `END'.  This makes a
+   call to the ARM_SYNC_ICACHE architecture specific syscall.  */
+#define CLEAR_INSN_CACHE(BEG, END)					\
+do									\
+  {									\
+    extern int sysarch(int number, void *args);				\
+    struct {								\
+	unsigned int addr;						\
+	int          len;						\
+    } s;								\
+    s.addr = (unsigned int)(BEG);					\
+    s.len = (END) - (BEG);						\
+    (void) sysarch (0, &s);						\
+  }									\
+while (0)