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/* This defaults us to little-endian. */ 31#ifndef TARGET_ENDIAN_DEFAULT 32#define TARGET_ENDIAN_DEFAULT 0 33#endif 34 35#undef MULTILIB_DEFAULTS 36 37/* Default it to use ATPCS with soft-VFP. */ 38#undef TARGET_DEFAULT 39#define TARGET_DEFAULT \ 40 (MASK_APCS_FRAME \ 41 | TARGET_ENDIAN_DEFAULT) 42 43#undef ARM_DEFAULT_ABI 44#define ARM_DEFAULT_ABI ARM_ABI_ATPCS 45 46#define TARGET_OS_CPP_BUILTINS() \ 47 do \ 48 { \ 49 NETBSD_OS_CPP_BUILTINS_ELF(); \ 50 } \ 51 while (0) 52 53#undef SUBTARGET_CPP_SPEC 54#define SUBTARGET_CPP_SPEC NETBSD_CPP_SPEC 55 56#undef SUBTARGET_EXTRA_ASM_SPEC 57#define SUBTARGET_EXTRA_ASM_SPEC \ 58 "-matpcs %{fpic|fpie:-k} %{fPIC|fPIE:-k}" 59 60/* Default to full VFP if -mfloat-abi=hard is specified. */ 61#undef SUBTARGET_ASM_FLOAT_SPEC 62#define SUBTARGET_ASM_FLOAT_SPEC \ 63 "%{mfloat-abi=hard:{!mfpu=*:-mfpu=vfp}}" 64 65#undef SUBTARGET_EXTRA_SPECS 66#define SUBTARGET_EXTRA_SPECS \ 67 { "subtarget_extra_asm_spec", SUBTARGET_EXTRA_ASM_SPEC }, \ 68 { "subtarget_asm_float_spec", SUBTARGET_ASM_FLOAT_SPEC }, \ 69 { "netbsd_link_spec", NETBSD_LINK_SPEC_ELF }, \ 70 { "netbsd_entry_point", NETBSD_ENTRY_POINT }, 71 72#define NETBSD_ENTRY_POINT "__start" 73 74#undef LINK_SPEC 75#define LINK_SPEC \ 76 "-X %{mbig-endian:-EB} %{mlittle-endian:-EL} \ 77 %(netbsd_link_spec)" 78 79/* Make GCC agree with <machine/ansi.h>. */ 80 81#undef SIZE_TYPE 82#define SIZE_TYPE "long unsigned int" 83 84#undef PTRDIFF_TYPE 85#define PTRDIFF_TYPE "long int" 86 87/* We don't have any limit on the length as out debugger is GDB. */ 88#undef DBX_CONTIN_LENGTH 89 90/* NetBSD does its profiling differently to the Acorn compiler. We 91 don't need a word following the mcount call; and to skip it 92 requires either an assembly stub or use of fomit-frame-pointer when 93 compiling the profiling functions. Since we break Acorn CC 94 compatibility below a little more won't hurt. */ 95 96#undef ARM_FUNCTION_PROFILER 97#define ARM_FUNCTION_PROFILER(STREAM,LABELNO) \ 98{ \ 99 asm_fprintf (STREAM, "\tmov\t%Rip, %Rlr\n"); \ 100 asm_fprintf (STREAM, "\tbl\t__mcount%s\n", \ 101 (TARGET_ARM && NEED_PLT_RELOC) \ 102 ? "(PLT)" : ""); \ 103} 104 105/* VERY BIG NOTE: Change of structure alignment for NetBSD/arm. 106 There are consequences you should be aware of... 107 108 Normally GCC/arm uses a structure alignment of 32 for compatibility 109 with armcc. This means that structures are padded to a word 110 boundary. However this causes problems with bugged NetBSD kernel 111 code (possibly userland code as well - I have not checked every 112 binary). The nature of this bugged code is to rely on sizeof() 113 returning the correct size of various structures rounded to the 114 nearest byte (SCSI and ether code are two examples, the vm system 115 is another). This code breaks when the structure alignment is 32 116 as sizeof() will report a word=rounded size. By changing the 117 structure alignment to 8. GCC will conform to what is expected by 118 NetBSD. 119 120 This has several side effects that should be considered. 121 1. Structures will only be aligned to the size of the largest member. 122 i.e. structures containing only bytes will be byte aligned. 123 structures containing shorts will be half word aligned. 124 structures containing ints will be word aligned. 125 126 This means structures should be padded to a word boundary if 127 alignment of 32 is required for byte structures etc. 128 129 2. A potential performance penalty may exist if strings are no longer 130 word aligned. GCC will not be able to use word load/stores to copy 131 short strings. 132 133 This modification is not encouraged but with the present state of the 134 NetBSD source tree it is currently the only solution that meets the 135 requirements. */ 136 137#undef DEFAULT_STRUCTURE_SIZE_BOUNDARY 138#define DEFAULT_STRUCTURE_SIZE_BOUNDARY 8 139 140/* Clear the instruction cache from `BEG' to `END'. This makes a 141 call to the ARM_SYNC_ICACHE architecture specific syscall. */ 142#define CLEAR_INSN_CACHE(BEG, END) \ 143do \ 144 { \ 145 extern int sysarch(int number, void *args); \ 146 struct \ 147 { \ 148 unsigned int addr; \ 149 int len; \ 150 } s; \ 151 s.addr = (unsigned int)(BEG); \ 152 s.len = (END) - (BEG); \ 153 (void) sysarch (0, &s); \ 154 } \ 155while (0) 156 157#undef FPUTYPE_DEFAULT 158#define FPUTYPE_DEFAULT "vfp" 159 160