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1/*
2 * Copyright (c) 2007 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * @OSF_COPYRIGHT@
30 */
31/*
32 * Mach Operating System
33 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
49 * School of Computer Science
50 * Carnegie Mellon University
51 * Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56
57#ifndef _ARM_ASM_H_
58#define _ARM_ASM_H_
59
60#include <arm/arch.h>
61
62#define FRAME pushl %ebp; movl %esp, %ebp
63#define EMARF leave
64
65
66/* There is another definition of ALIGN for .c sources */
67#ifdef ASSEMBLER
68#define ALIGN 2
69#endif /* ASSEMBLER */
70
71#ifndef FALIGN
72#define FALIGN ALIGN
73#endif
74
75#define LB(x,n) n
76#if __STDC__
77#ifndef __NO_UNDERSCORES__
78#define LCL(x) L ## x
79#define EXT(x) _ ## x
80#define LEXT(x) _ ## x ## :
81#else
82#define LCL(x) .L ## x
83#define EXT(x) x
84#define LEXT(x) x ## :
85#endif
86#define LBc(x,n) n ## :
87#define LBb(x,n) n ## b
88#define LBf(x,n) n ## f
89#else /* __STDC__ */
90#ifndef __NO_UNDERSCORES__
91#define LCL(x) L/**/x
92#define EXT(x) _/**/x
93#define LEXT(x) _/**/x/**/:
94#else /* __NO_UNDERSCORES__ */
95#define LCL(x) .L/**/x
96#define EXT(x) x
97#define LEXT(x) x/**/:
98#endif /* __NO_UNDERSCORES__ */
99#define LBc(x,n) n/**/:
100#define LBb(x,n) n/**/b
101#define LBf(x,n) n/**/f
102#endif /* __STDC__ */
103
104#define String .asciz
105#define Value .word
106#define Times(a,b) (a*b)
107#define Divide(a,b) (a/b)
108
109#if 0 /* TOTOJK */
110#ifdef __ELF__
111#define ELF_FUNC(x) .type x,@function
112#define ELF_DATA(x) .type x,@object
113#define ELF_SIZE(x,s) .size x,s
114#else
115#define ELF_FUNC(x)
116#define ELF_DATA(x)
117#define ELF_SIZE(x,s)
118#endif
119#else
120#define ELF_FUNC(x)
121#define ELF_DATA(x)
122#define ELF_SIZE(x,s)
123#endif /* TODOJK */
124
125#define Entry(x) .globl EXT(x); ELF_FUNC(EXT(x)); .align FALIGN; LEXT(x)
126#define ENTRY(x) Entry(x) MCOUNT
127#define ENTRY2(x,y) .globl EXT(x); .globl EXT(y); \
128 ELF_FUNC(EXT(x)); ELF_FUNC(EXT(y)); \
129 .align FALIGN; LEXT(x); LEXT(y) \
130 MCOUNT
131#if __STDC__
132#define ASENTRY(x) .globl x; .align FALIGN; x ## : ELF_FUNC(x) MCOUNT
133#else
134#define ASENTRY(x) .globl x; .align FALIGN; x: ELF_FUNC(x) MCOUNT
135#endif /* __STDC__ */
136
137#define DATA(x) .globl EXT(x); ELF_DATA(EXT(x)); .align ALIGN; LEXT(x)
138
139#define End(x) ELF_SIZE(x,.-x)
140#define END(x) End(EXT(x))
141#define ENDDATA(x) END(x)
142#define Enddata(x) End(x)
143
144#ifdef ASSEMBLER
145
146#define MCOUNT
147
148#else /* NOT ASSEMBLER */
149
150/* These defines are here for .c files that wish to reference global symbols
151 * within __asm__ statements.
152 */
153#ifndef __NO_UNDERSCORES__
154#define CC_SYM_PREFIX "_"
155#else
156#define CC_SYM_PREFIX ""
157#endif /* __NO_UNDERSCORES__ */
158#endif /* ASSEMBLER */
159
160#ifdef ASSEMBLER
161
162#if defined (_ARM_ARCH_4T)
163# define RET bx lr
164# define RETeq bxeq lr
165# define RETne bxne lr
166# ifdef __STDC__
167# define RETc(c) bx##c lr
168# else
169# define RETc(c) bx/**/c lr
170# endif
171#else
172# define RET mov pc, lr
173# define RETeq moveq pc, lr
174# define RETne movne pc, lr
175# ifdef __STDC__
176# define RETc(c) mov##c pc, lr
177# else
178# define RETc(c) mov/**/c pc, lr
179# endif
180#endif
181
182#if defined (__thumb__)
183/* Provide a PI mechanism for thumb branching. */
184# define BRANCH_EXTERN(x) ldr pc, [pc, #-4] ; \
185 .long EXT(x)
186#else
187# define BRANCH_EXTERN(x) b EXT(x)
188#endif
189
190/*
191 * arg0: Register for thread pointer
192 */
193.macro READ_THREAD
194 mrc p15, 0, $0, c13, c0, 4 /* Read TPIDRPRW */
195.endmacro
196
197
198/* Macros for loading up addresses that are external to the .s file.
199 * LOAD_ADDR: loads the address for (label) into (reg). Not safe for
200 * loading to the PC.
201 * LOAD_ADDR_PC: Variant for loading to the PC; load the address of (label)
202 * into the pc.
203 * LOAD_ADDR_GEN_DEF: The general definition needed to support loading
204 * a label address.
205 *
206 * Usage: For any label accessed, we require one (and only one) instance
207 * of LOAD_ADDR_GEN_DEF(label).
208 *
209 * Example:
210 * LOAD_ADDR(r0, arm_init)
211 * LOAD_ADDR(lr, arm_init_cpu)
212 * LOAD_ADDR_PC(arm_init)
213 * ...
214 *
215 * LOAD_ADDR_GEN_DEF(arm_init)
216 * LOAD_ADDR_GEN_DEF(arm_init_cpu)
217 */
218
219#if SLIDABLE
220/* Definitions for a position dependent kernel using non-lazy pointers.
221 */
222
223/* TODO: Make this work with thumb .s files. */
224#define PC_INC 0x8
225
226/* We need wrapper macros in order to ensure that __LINE__ is expanded.
227 *
228 * There is some small potential for duplicate labels here, but because
229 * we do not export the generated labels, it should not be an issue.
230 */
231
232#define GLUE_LABEL_GUTS(label, tag) L_##label##_##tag##_glue
233#define GLUE_LABEL(label, tag) GLUE_LABEL_GUTS(label, tag)
234
235#define LOAD_ADDR(reg, label) \
236 movw reg, :lower16:(label##$non_lazy_ptr - (GLUE_LABEL(label, __LINE__) + PC_INC)) ; \
237 movt reg, :upper16:(label##$non_lazy_ptr - (GLUE_LABEL(label, __LINE__) + PC_INC)) ; \
238GLUE_LABEL(label, __LINE__): ; \
239 ldr reg, [pc, reg]
240
241/* Designed with the understanding that directly branching to thumb code
242 * is unreliable; this should allow for dealing with __thumb__ in
243 * assembly; the non-thumb variant still needs to provide the glue label
244 * to avoid failing to build on undefined symbols.
245 *
246 * TODO: Make this actually use a scratch register; this macro is convenient
247 * for translating (ldr pc, [?]) to a slidable format without the risk of
248 * clobbering registers, but it is also wasteful.
249 */
250#if defined(__thumb__)
251#define LOAD_ADDR_PC(label) \
252 stmfd sp!, { r0 } ; \
253 stmfd sp!, { r0 } ; \
254 LOAD_ADDR(r0, label) ; \
255 str r0, [sp, #4] ; \
256 ldmfd sp!, { r0 } ; \
257 ldmfd sp!, { pc }
258#else
259#define LOAD_ADDR_PC(label) \
260 b EXT(label)
261#endif
262
263#define LOAD_ADDR_GEN_DEF(label) \
264 .section __DATA,__nl_symbol_ptr,non_lazy_symbol_pointers ; \
265 .align 2 ; \
266label##$non_lazy_ptr: ; \
267 .indirect_symbol EXT(label) ; \
268 .long 0
269
270#else /* !SLIDABLE */
271
272/* Definitions for a position dependent kernel */
273#define LOAD_ADDR(reg, label) \
274 ldr reg, L_##label
275
276#if defined(__thumb__)
277#define LOAD_ADDR_PC(label) \
278 ldr pc, L_##label
279#else
280#define LOAD_ADDR_PC(label) \
281 b EXT(label)
282#endif
283
284#define LOAD_ADDR_GEN_DEF(label) \
285 .text ; \
286 .align 2 ; \
287L_##label: ; \
288 .long EXT(label)
289
290#endif /* SLIDABLE */
291
292/* The linker can deal with branching from ARM to thumb in unconditional
293 * branches, but not in conditional branches. To support this in our
294 * assembly (which allows us to build xnu without -mno-thumb), use the
295 * following macros for branching conditionally to external symbols.
296 * These macros are used just like the corresponding conditional branch
297 * instructions.
298 */
299
300#define SHIM_LABEL_GUTS(line_num) L_cond_extern_##line_num##_shim
301#define SHIM_LABEL(line_num) SHIM_LABEL_GUTS(line_num)
302
303#define COND_EXTERN_BEQ(label) \
304 bne SHIM_LABEL(__LINE__) ; \
305 b EXT(label) ; \
306SHIM_LABEL(__LINE__):
307
308#define COND_EXTERN_BLNE(label) \
309 beq SHIM_LABEL(__LINE__) ; \
310 bl EXT(label) ; \
311SHIM_LABEL(__LINE__):
312
313#define COND_EXTERN_BLGT(label) \
314 ble SHIM_LABEL(__LINE__) ; \
315 bl EXT(label) ; \
316SHIM_LABEL(__LINE__):
317
318#endif /* ASSEMBLER */
319
320#endif /* _ARM_ASM_H_ */