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ff3afb56 | 1 | /* Definitions of target machine for GNU compiler, NetBSD/arm ELF version. |
a5544970 | 2 | Copyright (C) 2002-2019 Free Software Foundation, Inc. |
ff3afb56 JT |
3 | Contributed by Wasabi Systems, Inc. |
4 | ||
4f448245 | 5 | This file is part of GCC. |
ff3afb56 | 6 | |
4f448245 NC |
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 | |
2f83c7d6 | 9 | by the Free Software Foundation; either version 3, or (at your |
4f448245 | 10 | option) any later version. |
ff3afb56 | 11 | |
4f448245 NC |
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. | |
ff3afb56 | 16 | |
999db125 GJL |
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 | ||
c7eca9fe GJL |
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 | |
2f83c7d6 | 24 | <http://www.gnu.org/licenses/>. */ |
ff3afb56 JT |
25 | |
26 | /* Run-time Target Specification. */ | |
ff3afb56 | 27 | |
ff3afb56 JT |
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 \ | |
c54c7322 | 40 | (MASK_APCS_FRAME \ |
ff3afb56 JT |
41 | | TARGET_ENDIAN_DEFAULT) |
42 | ||
5848830f PB |
43 | #undef ARM_DEFAULT_ABI |
44 | #define ARM_DEFAULT_ABI ARM_ABI_ATPCS | |
45 | ||
ff3afb56 JT |
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 \ | |
428b3812 | 58 | "-matpcs %{" FPIE_OR_FPIC_SPEC ":-k}" |
ff3afb56 | 59 | |
5e1b4d5a | 60 | /* Default to full VFP if -mfloat-abi=hard is specified. */ |
ff3afb56 JT |
61 | #undef SUBTARGET_ASM_FLOAT_SPEC |
62 | #define SUBTARGET_ASM_FLOAT_SPEC \ | |
5e1b4d5a | 63 | "%{mfloat-abi=hard:{!mfpu=*:-mfpu=vfp}}" |
ff3afb56 JT |
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", \ | |
f92ba6d1 DJ |
101 | (TARGET_ARM && NEED_PLT_RELOC) \ |
102 | ? "(PLT)" : ""); \ | |
ff3afb56 JT |
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. | |
6bc82793 | 123 | structures containing shorts will be half word aligned. |
ff3afb56 JT |
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 | ||
ff3afb56 JT |
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) \ | |
143 | do \ | |
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 | } \ | |
155 | while (0) |