1 /* Definitions of target machine for GNU compiler, NetBSD/arm ELF version. 2 Copyright (C) 2002-2015 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 Under Section 7 of GPL version 3, you are granted additional 18 permissions described in the GCC Runtime Library Exception, version 19 3.1, as published by the Free Software Foundation. 20 21 You should have received a copy of the GNU General Public License and 22 a copy of the GCC Runtime Library Exception along with this program; 23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 <http://www.gnu.org/licenses/>. */ 25 26 /* Run-time Target Specification. */ 27 28 /* arm.h defaults to ARM6 CPU. */ 29 30 /* Default EABI to armv5t so that thumb shared libraries work. 31 The ARM926EH-S core is the default for armv5te, so set 32 SUBTARGET_CPU_DEFAULT to achieve this. */ 33 34 #define SUBTARGET_CPU_DEFAULT \ 35 (ARM_DEFAULT_ABI != ARM_ABI_APCS && ARM_DEFAULT_ABI != ARM_ABI_ATPCS \ 36 ? TARGET_CPU_arm926ejs : TARGET_CPU_arm6) 37 38 /* TARGET_BIG_ENDIAN_DEFAULT is set in 39 config.gcc for big endian configurations. */ 40 #if TARGET_BIG_ENDIAN_DEFAULT 41 #define TARGET_ENDIAN_DEFAULT MASK_BIG_END 42 #else 43 #define TARGET_ENDIAN_DEFAULT 0 44 #endif 45 46 #undef MULTILIB_DEFAULTS 47 48 /* Default it to use ATPCS with soft-VFP. */ 49 #undef TARGET_DEFAULT 50 #define TARGET_DEFAULT \ 51 (MASK_APCS_FRAME \ 52 | TARGET_ENDIAN_DEFAULT) 53 54 #undef ARM_DEFAULT_ABI 55 #define ARM_DEFAULT_ABI ARM_ABI_ATPCS 56 57 #undef TARGET_OS_CPP_BUILTINS 58 #define TARGET_OS_CPP_BUILTINS() \ 59 do \ 60 { \ 61 NETBSD_OS_CPP_BUILTINS_ELF(); \ 62 } \ 63 while (0) 64 65 #undef SUBTARGET_CPP_SPEC 66 #define SUBTARGET_CPP_SPEC NETBSD_CPP_SPEC 67 68 #undef SUBTARGET_EXTRA_ASM_SPEC 69 #define SUBTARGET_EXTRA_ASM_SPEC \ 70 "-matpcs %{mabi=aapcs*:-meabi=5} %{fpic|fpie:-k} %{fPIC|fPIE:-k}" 71 72 /* Default to full VFP if -mfloat-abi=hard is specified. */ 73 #undef SUBTARGET_ASM_FLOAT_SPEC 74 #define SUBTARGET_ASM_FLOAT_SPEC \ 75 "%{mhard-float:%{!mfpu=*:-mfpu=vfp}} \ 76 %{mfloat-abi=hard:%{!mfpu=*:-mfpu=vfp}}" 77 78 #define NETBSD_ENTRY_POINT "__start" 79 80 #undef LINK_SPEC 81 #define LINK_SPEC \ 82 "-X \ 83 %{mbig-endian:-EB %{-mabi=aapcs*:-m armelfb_nbsd_eabi}} \ 84 %{mlittle-endian:-EL %{-mabi=aapcs*:-m armelf_nbsd_eabi}} \ 85 %(netbsd_link_spec)" 86 87 /* Make GCC agree with <machine/ansi.h>. */ 88 89 #undef SIZE_TYPE 90 #define SIZE_TYPE "long unsigned int" 91 92 #undef PTRDIFF_TYPE 93 #define PTRDIFF_TYPE "long int" 94 95 #undef INTPTR_TYPE 96 #define INTPTR_TYPE PTRDIFF_TYPE 97 98 #undef UINTPTR_TYPE 99 #define UINTPTR_TYPE SIZE_TYPE 100 101 /* We don't have any limit on the length as out debugger is GDB. */ 102 #undef DBX_CONTIN_LENGTH 103 104 /* NetBSD does its profiling differently to the Acorn compiler. We 105 don't need a word following the mcount call; and to skip it 106 requires either an assembly stub or use of fomit-frame-pointer when 107 compiling the profiling functions. Since we break Acorn CC 108 compatibility below a little more won't hurt. */ 109 110 #undef ARM_FUNCTION_PROFILER 111 #define ARM_FUNCTION_PROFILER(STREAM,LABELNO) \ 112 { \ 113 asm_fprintf (STREAM, "\tmov\t%Rip, %Rlr\n"); \ 114 asm_fprintf (STREAM, "\tbl\t__mcount%s\n", \ 115 (TARGET_ARM && NEED_PLT_RELOC) \ 116 ? "(PLT)" : ""); \ 117 } 118 119 /* VERY BIG NOTE: Change of structure alignment for NetBSD/arm. 120 There are consequences you should be aware of... 121 122 Normally GCC/arm uses a structure alignment of 32 for compatibility 123 with armcc. This means that structures are padded to a word 124 boundary. However this causes problems with bugged NetBSD kernel 125 code (possibly userland code as well - I have not checked every 126 binary). The nature of this bugged code is to rely on sizeof() 127 returning the correct size of various structures rounded to the 128 nearest byte (SCSI and ether code are two examples, the vm system 129 is another). This code breaks when the structure alignment is 32 130 as sizeof() will report a word=rounded size. By changing the 131 structure alignment to 8. GCC will conform to what is expected by 132 NetBSD. 133 134 This has several side effects that should be considered. 135 1. Structures will only be aligned to the size of the largest member. 136 i.e. structures containing only bytes will be byte aligned. 137 structures containing shorts will be half word aligned. 138 structures containing ints will be word aligned. 139 140 This means structures should be padded to a word boundary if 141 alignment of 32 is required for byte structures etc. 142 143 2. A potential performance penalty may exist if strings are no longer 144 word aligned. GCC will not be able to use word load/stores to copy 145 short strings. 146 147 This modification is not encouraged but with the present state of the 148 NetBSD source tree it is currently the only solution that meets the 149 requirements. */ 150 151 #undef DEFAULT_STRUCTURE_SIZE_BOUNDARY 152 #define DEFAULT_STRUCTURE_SIZE_BOUNDARY 8 153 154 /* Clear the instruction cache from `BEG' to `END'. This makes a 155 call to the ARM_SYNC_ICACHE architecture specific syscall. */ 156 #define CLEAR_INSN_CACHE(BEG, END) \ 157 do \ 158 { \ 159 extern int sysarch(int number, void *args); \ 160 struct \ 161 { \ 162 unsigned int addr; \ 163 int len; \ 164 } s; \ 165 s.addr = (unsigned int)(BEG); \ 166 s.len = (END) - (BEG); \ 167 (void) sysarch (0, &s); \ 168 } \ 169 while (0) 170 171 #undef FPUTYPE_DEFAULT 172 #define FPUTYPE_DEFAULT "vfp" 173 174 /* Ensure that libgcc does not attempt to define __[CD]TOR_LIST__[] for APCS, 175 which belongs in crtbegin on NetBSD. */ 176 #ifndef __ARM_EABI__ 177 #define CTOR_LISTS_DEFINED_EXTERNALLY 178 #endif 179