1/* Definitions of target machine for GNU compiler, NetBSD/arm ELF version.
2   Copyright (C) 2002, 2003, 2004, 2005 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 2, 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 COPYING.  If not, write to
19   the Free Software Foundation, 51 Franklin Street, Fifth Floor,
20   Boston, MA 02110-1301, USA.  */
21
22/* Run-time Target Specification.  */
23#undef TARGET_VERSION
24#define TARGET_VERSION fputs (" (NetBSD/arm ELF)", stderr);
25
26/* arm.h defaults to ARM6 CPU.  */
27
28/* This defaults us to little-endian.  */
29#ifndef TARGET_ENDIAN_DEFAULT
30#define TARGET_ENDIAN_DEFAULT 0
31#endif
32
33#undef MULTILIB_DEFAULTS
34
35/* Default it to use ATPCS with soft-VFP.  */
36#undef TARGET_DEFAULT
37#define TARGET_DEFAULT			\
38  (MASK_APCS_FRAME			\
39   | TARGET_ENDIAN_DEFAULT)
40
41#undef ARM_DEFAULT_ABI
42#define ARM_DEFAULT_ABI ARM_ABI_ATPCS
43
44#define TARGET_OS_CPP_BUILTINS()	\
45  do					\
46    {					\
47      NETBSD_OS_CPP_BUILTINS_ELF();	\
48    }					\
49  while (0)
50
51#undef SUBTARGET_CPP_SPEC
52#define SUBTARGET_CPP_SPEC NETBSD_CPP_SPEC
53
54#undef SUBTARGET_EXTRA_ASM_SPEC
55#define SUBTARGET_EXTRA_ASM_SPEC	\
56  "-matpcs %{fpic|fpie:-k} %{fPIC|fPIE:-k}"
57
58/* Default to full VFP if -mhard-float is specified.  */
59#undef SUBTARGET_ASM_FLOAT_SPEC
60#define SUBTARGET_ASM_FLOAT_SPEC	\
61  "%{mhard-float:{!mfpu=*:-mfpu=vfp}}   \
62   %{mfloat-abi=hard:{!mfpu=*:-mfpu=vfp}}"
63
64#undef SUBTARGET_EXTRA_SPECS
65#define SUBTARGET_EXTRA_SPECS				\
66  { "subtarget_extra_asm_spec",	SUBTARGET_EXTRA_ASM_SPEC }, \
67  { "subtarget_asm_float_spec", SUBTARGET_ASM_FLOAT_SPEC }, \
68  { "netbsd_link_spec",		NETBSD_LINK_SPEC_ELF },	\
69  { "netbsd_entry_point",	NETBSD_ENTRY_POINT },
70
71#define NETBSD_ENTRY_POINT "__start"
72
73#undef LINK_SPEC
74#define LINK_SPEC \
75  "-X %{mbig-endian:-EB} %{mlittle-endian:-EL} \
76   %(netbsd_link_spec)"
77
78/* Make GCC agree with <machine/ansi.h>.  */
79
80#undef SIZE_TYPE
81#define SIZE_TYPE "long unsigned int"
82
83#undef PTRDIFF_TYPE
84#define PTRDIFF_TYPE "long int"
85
86/* We don't have any limit on the length as out debugger is GDB.  */
87#undef DBX_CONTIN_LENGTH
88
89/* NetBSD does its profiling differently to the Acorn compiler. We
90   don't need a word following the mcount call; and to skip it
91   requires either an assembly stub or use of fomit-frame-pointer when
92   compiling the profiling functions.  Since we break Acorn CC
93   compatibility below a little more won't hurt.  */
94
95#undef ARM_FUNCTION_PROFILER
96#define ARM_FUNCTION_PROFILER(STREAM,LABELNO)		\
97{							\
98  asm_fprintf (STREAM, "\tmov\t%Rip, %Rlr\n");		\
99  asm_fprintf (STREAM, "\tbl\t__mcount%s\n",		\
100	       (TARGET_ARM && NEED_PLT_RELOC)		\
101	       ? "(PLT)" : "");				\
102}
103
104/* VERY BIG NOTE: Change of structure alignment for NetBSD/arm.
105   There are consequences you should be aware of...
106
107   Normally GCC/arm uses a structure alignment of 32 for compatibility
108   with armcc.  This means that structures are padded to a word
109   boundary.  However this causes problems with bugged NetBSD kernel
110   code (possibly userland code as well - I have not checked every
111   binary).  The nature of this bugged code is to rely on sizeof()
112   returning the correct size of various structures rounded to the
113   nearest byte (SCSI and ether code are two examples, the vm system
114   is another).  This code breaks when the structure alignment is 32
115   as sizeof() will report a word=rounded size.  By changing the
116   structure alignment to 8. GCC will conform to what is expected by
117   NetBSD.
118
119   This has several side effects that should be considered.
120   1. Structures will only be aligned to the size of the largest member.
121      i.e. structures containing only bytes will be byte aligned.
122           structures containing shorts will be half word aligned.
123           structures containing ints will be word aligned.
124
125      This means structures should be padded to a word boundary if
126      alignment of 32 is required for byte structures etc.
127
128   2. A potential performance penalty may exist if strings are no longer
129      word aligned.  GCC will not be able to use word load/stores to copy
130      short strings.
131
132   This modification is not encouraged but with the present state of the
133   NetBSD source tree it is currently the only solution that meets the
134   requirements.  */
135
136#undef DEFAULT_STRUCTURE_SIZE_BOUNDARY
137#define DEFAULT_STRUCTURE_SIZE_BOUNDARY 8
138
139/* Clear the instruction cache from `BEG' to `END'.  This makes a
140   call to the ARM_SYNC_ICACHE architecture specific syscall.  */
141#define CLEAR_INSN_CACHE(BEG, END)					\
142do									\
143  {									\
144    extern int sysarch(int number, void *args);				\
145    struct								\
146      {									\
147	unsigned int addr;						\
148	int          len;						\
149      } s;								\
150    s.addr = (unsigned int)(BEG);					\
151    s.len = (END) - (BEG);						\
152    (void) sysarch (0, &s);						\
153  }									\
154while (0)
155
156#undef FPUTYPE_DEFAULT
157#define FPUTYPE_DEFAULT FPUTYPE_VFP
158
159