1/* NetBSD/arm (RiscBSD) version. 2 Copyright (C) 1993, 1994, 1997, 1998 Free Software Foundation, Inc. 3 Contributed by Mark Brinicombe (amb@physig.ph.kcl.ac.uk) 4 5This file is part of GNU CC. 6 7GNU CC is free software; you can redistribute it and/or modify 8it under the terms of the GNU General Public License as published by 9the Free Software Foundation; either version 2, or (at your option) 10any later version. 11 12GNU CC is distributed in the hope that it will be useful, 13but WITHOUT ANY WARRANTY; without even the implied warranty of 14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15GNU General Public License for more details. 16 17You should have received a copy of the GNU General Public License 18along with GNU CC; see the file COPYING. If not, write to 19the Free Software Foundation, 59 Temple Place - Suite 330, 20Boston, MA 02111-1307, USA. */ 21 22/* Run-time Target Specification. */ 23#define TARGET_VERSION fputs (" (ARM/NetBSD)", stderr); 24 25/* This is used in ASM_FILE_START. */ 26#define ARM_OS_NAME "NetBSD" 27 28/* Unsigned chars produces much better code than signed. */ 29#define DEFAULT_SIGNED_CHAR 0 30 31/* Since we always use GAS as our assembler we support stabs. */ 32#define DBX_DEBUGGING_INFO 1 33 34/*#undef ASM_DECLARE_FUNCTION_NAME*/ 35 36/* ARM6 family default cpu. */ 37#define SUBTARGET_CPU_DEFAULT TARGET_CPU_arm6 38 39/* Default is to use APCS-32 mode. */ 40#define TARGET_DEFAULT (ARM_FLAG_APCS_32 | ARM_FLAG_SOFT_FLOAT) 41 42#include "arm/aout.h" 43 44/* This gets redefined in config/netbsd.h. */ 45#undef TARGET_MEM_FUNCTIONS 46 47#include <netbsd.h> 48 49/* Until they use ELF or something that handles dwarf2 unwinds 50 and initialization stuff better. */ 51#undef DWARF2_UNWIND_INFO 52 53/* Some defines for CPP. 54 arm32 is the NetBSD port name, so we always define arm32 and __arm32__. */ 55#undef CPP_PREDEFINES 56#define CPP_PREDEFINES "\ 57-Dunix -Driscbsd -Darm32 -D__arm32__ -D__arm__ -D__NetBSD__ \ 58-Asystem(unix) -Asystem(NetBSD) -Acpu(arm) -Amachine(arm)" 59 60/* Define _POSIX_SOURCE if necessary. */ 61#undef CPP_SPEC 62#define CPP_SPEC "\ 63%(cpp_cpu_arch) %(cpp_apcs_pc) %(cpp_float) %(cpp_endian) \ 64%{posix:-D_POSIX_SOURCE} \ 65" 66 67/* Because TARGET_DEFAULT sets ARM_FLAG_APCS_32 */ 68#undef CPP_APCS_PC_DEFAULT_SPEC 69#define CPP_APCS_PC_DEFAULT_SPEC "-D__APCS_32__" 70 71/* Because TARGET_DEFAULT sets ARM_FLAG_SOFT_FLOAT */ 72#undef CPP_FLOAT_DEFAULT_SPEC 73#define CPP_FLOAT_DEFAULT_SPEC "-D__SOFTFP__" 74 75/* Pass -X to the linker so that it will strip symbols starting with 'L' */ 76#undef LINK_SPEC 77#define LINK_SPEC "\ 78-X %{!nostdlib:%{!r*:%{!e*:-e start}}} -dc -dp %{R*} \ 79%{static:-Bstatic} %{assert*} \ 80" 81 82#undef SIZE_TYPE 83#define SIZE_TYPE "unsigned int" 84 85#undef PTRDIFF_TYPE 86#define PTRDIFF_TYPE "int" 87 88#undef WCHAR_TYPE 89#define WCHAR_TYPE "int" 90 91#undef WCHAR_UNSIGNED 92#define WCHAR_UNSIGNED 0 93 94#undef WCHAR_TYPE_SIZE 95#define WCHAR_TYPE_SIZE 32 96 97#define HANDLE_SYSV_PRAGMA 98 99/* We don't have any limit on the length as out debugger is GDB. */ 100#undef DBX_CONTIN_LENGTH 101 102/* NetBSD does its profiling differently to the Acorn compiler. We 103 don't need a word following the mcount call; and to skip it 104 requires either an assembly stub or use of fomit-frame-pointer when 105 compiling the profiling functions. Since we break Acorn CC 106 compatibility below a little more won't hurt. */ 107 108#undef FUNCTION_PROFILER 109#define FUNCTION_PROFILER(STREAM,LABELNO) \ 110{ \ 111 fprintf(STREAM, "\tmov\t%sip, %slr\n", REGISTER_PREFIX, REGISTER_PREFIX); \ 112 fprintf(STREAM, "\tbl\tmcount\n"); \ 113} 114 115/* On the ARM `@' introduces a comment, so we must use something else 116 for .type directives. */ 117#undef TYPE_OPERAND_FMT 118#define TYPE_OPERAND_FMT "%%%s" 119 120/* NetBSD uses the old PCC style aggregate returning conventions. */ 121#undef DEFAULT_PCC_STRUCT_RETURN 122#define DEFAULT_PCC_STRUCT_RETURN 1 123 124/* Although not normally relevant (since by default, all aggregates 125 are returned in memory) compiling some parts of libc requires 126 non-APCS style struct returns. */ 127#undef RETURN_IN_MEMORY 128 129/* VERY BIG NOTE : Change of structure alignment for RiscBSD. 130 There are consequences you should be aware of... 131 132 Normally GCC/arm uses a structure alignment of 32 for compatibility 133 with armcc. This means that structures are padded to a word 134 boundary. However this causes problems with bugged NetBSD kernel 135 code (possibly userland code as well - I have not checked every 136 binary). The nature of this bugged code is to rely on sizeof() 137 returning the correct size of various structures rounded to the 138 nearest byte (SCSI and ether code are two examples, the vm system 139 is another). This code breaks when the structure alignment is 32 140 as sizeof() will report a word=rounded size. By changing the 141 structure alignment to 8. GCC will conform to what is expected by 142 NetBSD. 143 144 This has several side effects that should be considered. 145 1. Structures will only be aligned to the size of the largest member. 146 i.e. structures containing only bytes will be byte aligned. 147 structures containing shorts will be half word alinged. 148 structures containing ints will be word aligned. 149 150 This means structures should be padded to a word boundary if 151 alignment of 32 is required for byte structures etc. 152 153 2. A potential performance penalty may exist if strings are no longer 154 word aligned. GCC will not be able to use word load/stores to copy 155 short strings. 156 157 This modification is not encouraged but with the present state of the 158 NetBSD source tree it is currently the only solution that meets the 159 requirements. */ 160#undef STRUCTURE_SIZE_BOUNDARY 161#define STRUCTURE_SIZE_BOUNDARY 8 162