1 /* Definitions of target machine for GNU compiler, NetBSD/arm ELF version. 2 Copyright (C) 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc. 3 Contributed by Wasabi Systems, Inc. 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify it 8 under the terms of the GNU General Public License as published 9 by the Free Software Foundation; either version 3, or (at your 10 option) any later version. 11 12 GCC is distributed in the hope that it will be useful, but WITHOUT 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public 15 License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. */ 20 21 /* Run-time Target Specification. */ 22 #undef TARGET_VERSION 23 #define TARGET_VERSION fputs (" (NetBSD/arm ELF)", stderr); 24 25 /* arm.h defaults to ARM6 CPU. */ 26 27 /* Default EABI to armv5t so that thumb shared libraries work. 28 The ARM926EH-S core is the default for armv5te, so set 29 SUBTARGET_CPU_DEFAULT to achieve this. */ 30 31 #define SUBTARGET_CPU_DEFAULT \ 32 (ARM_DEFAULT_ABI != ARM_ABI_APCS && ARM_DEFAULT_ABI != ARM_ABI_ATPCS \ 33 ? TARGET_CPU_arm926ejs : TARGET_CPU_arm6) 34 35 /* This defaults us to little-endian. */ 36 #ifndef TARGET_ENDIAN_DEFAULT 37 #define TARGET_ENDIAN_DEFAULT 0 38 #endif 39 40 #undef MULTILIB_DEFAULTS 41 42 /* Default it to use ATPCS with soft-VFP. */ 43 #undef TARGET_DEFAULT 44 #define TARGET_DEFAULT \ 45 (MASK_APCS_FRAME \ 46 | TARGET_ENDIAN_DEFAULT) 47 48 #undef ARM_DEFAULT_ABI 49 #define ARM_DEFAULT_ABI ARM_ABI_ATPCS 50 51 #undef TARGET_OS_CPP_BUILTINS 52 #define TARGET_OS_CPP_BUILTINS() \ 53 do \ 54 { \ 55 NETBSD_OS_CPP_BUILTINS_ELF(); \ 56 } \ 57 while (0) 58 59 #undef SUBTARGET_CPP_SPEC 60 #define SUBTARGET_CPP_SPEC NETBSD_CPP_SPEC 61 62 #undef SUBTARGET_EXTRA_ASM_SPEC 63 #define SUBTARGET_EXTRA_ASM_SPEC \ 64 "-matpcs %{mabi=aapcs*:-meabi=5} %{fpic|fpie:-k} %{fPIC|fPIE:-k}" 65 66 /* Default to full VFP if -mhard-float is specified. */ 67 #undef SUBTARGET_ASM_FLOAT_SPEC 68 #define SUBTARGET_ASM_FLOAT_SPEC \ 69 "%{mhard-float:%{!mfpu=*:-mfpu=vfp}} \ 70 %{mfloat-abi=hard:%{!mfpu=*:-mfpu=vfp}}" 71 72 #undef SUBTARGET_EXTRA_SPECS 73 #define SUBTARGET_EXTRA_SPECS \ 74 { "subtarget_extra_asm_spec", SUBTARGET_EXTRA_ASM_SPEC }, \ 75 { "subtarget_asm_float_spec", SUBTARGET_ASM_FLOAT_SPEC }, \ 76 { "netbsd_link_spec", NETBSD_LINK_SPEC_ELF }, \ 77 { "netbsd_entry_point", NETBSD_ENTRY_POINT }, 78 79 #define NETBSD_ENTRY_POINT "__start" 80 81 #undef LINK_SPEC 82 #define LINK_SPEC \ 83 "-X \ 84 %{mbig-endian:-EB %{-mabi=aapcs*:-m armelfb_nbsd_eabi}} \ 85 %{mlittle-endian:-EL %{-mabi=aapcs*:-m armelf_nbsd_eabi}} \ 86 %(netbsd_link_spec)" 87 88 /* Make GCC agree with <machine/ansi.h>. */ 89 90 #undef SIZE_TYPE 91 #define SIZE_TYPE "long unsigned int" 92 93 #undef PTRDIFF_TYPE 94 #define PTRDIFF_TYPE "long int" 95 96 #undef INTPTR_TYPE 97 #define INTPTR_TYPE PTRDIFF_TYPE 98 99 #undef UINTPTR_TYPE 100 #define UINTPTR_TYPE SIZE_TYPE 101 102 /* We don't have any limit on the length as out debugger is GDB. */ 103 #undef DBX_CONTIN_LENGTH 104 105 /* NetBSD does its profiling differently to the Acorn compiler. We 106 don't need a word following the mcount call; and to skip it 107 requires either an assembly stub or use of fomit-frame-pointer when 108 compiling the profiling functions. Since we break Acorn CC 109 compatibility below a little more won't hurt. */ 110 111 #undef ARM_FUNCTION_PROFILER 112 #define ARM_FUNCTION_PROFILER(STREAM,LABELNO) \ 113 { \ 114 asm_fprintf (STREAM, "\tmov\t%Rip, %Rlr\n"); \ 115 asm_fprintf (STREAM, "\tbl\t__mcount%s\n", \ 116 (TARGET_ARM && NEED_PLT_RELOC) \ 117 ? "(PLT)" : ""); \ 118 } 119 120 /* VERY BIG NOTE: Change of structure alignment for NetBSD/arm. 121 There are consequences you should be aware of... 122 123 Normally GCC/arm uses a structure alignment of 32 for compatibility 124 with armcc. This means that structures are padded to a word 125 boundary. However this causes problems with bugged NetBSD kernel 126 code (possibly userland code as well - I have not checked every 127 binary). The nature of this bugged code is to rely on sizeof() 128 returning the correct size of various structures rounded to the 129 nearest byte (SCSI and ether code are two examples, the vm system 130 is another). This code breaks when the structure alignment is 32 131 as sizeof() will report a word=rounded size. By changing the 132 structure alignment to 8. GCC will conform to what is expected by 133 NetBSD. 134 135 This has several side effects that should be considered. 136 1. Structures will only be aligned to the size of the largest member. 137 i.e. structures containing only bytes will be byte aligned. 138 structures containing shorts will be half word aligned. 139 structures containing ints will be word aligned. 140 141 This means structures should be padded to a word boundary if 142 alignment of 32 is required for byte structures etc. 143 144 2. A potential performance penalty may exist if strings are no longer 145 word aligned. GCC will not be able to use word load/stores to copy 146 short strings. 147 148 This modification is not encouraged but with the present state of the 149 NetBSD source tree it is currently the only solution that meets the 150 requirements. */ 151 152 #undef DEFAULT_STRUCTURE_SIZE_BOUNDARY 153 #define DEFAULT_STRUCTURE_SIZE_BOUNDARY 8 154 155 /* Clear the instruction cache from `BEG' to `END'. This makes a 156 call to the ARM_SYNC_ICACHE architecture specific syscall. */ 157 #define CLEAR_INSN_CACHE(BEG, END) \ 158 do \ 159 { \ 160 extern int sysarch(int number, void *args); \ 161 struct \ 162 { \ 163 unsigned int addr; \ 164 int len; \ 165 } s; \ 166 s.addr = (unsigned int)(BEG); \ 167 s.len = (END) - (BEG); \ 168 (void) sysarch (0, &s); \ 169 } \ 170 while (0) 171 172 #undef FPUTYPE_DEFAULT 173 #define FPUTYPE_DEFAULT "vfp" 174 175