Commit | Line | Data |
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faf5f7ad | 1 | /* GNU/Linux on ARM target support. |
0fd88904 | 2 | |
1c63d086 | 3 | Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 |
8e9d1a24 | 4 | Free Software Foundation, Inc. |
faf5f7ad SB |
5 | |
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 10 | the Free Software Foundation; either version 3 of the License, or |
faf5f7ad SB |
11 | (at your option) any later version. |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
faf5f7ad SB |
20 | |
21 | #include "defs.h" | |
c20f6dea SB |
22 | #include "target.h" |
23 | #include "value.h" | |
faf5f7ad | 24 | #include "gdbtypes.h" |
134e61c4 | 25 | #include "floatformat.h" |
2a451106 KB |
26 | #include "gdbcore.h" |
27 | #include "frame.h" | |
4e052eda | 28 | #include "regcache.h" |
d16aafd8 | 29 | #include "doublest.h" |
7aa1783e | 30 | #include "solib-svr4.h" |
4be87837 | 31 | #include "osabi.h" |
cb587d83 | 32 | #include "regset.h" |
8e9d1a24 DJ |
33 | #include "trad-frame.h" |
34 | #include "tramp-frame.h" | |
daddc3c1 | 35 | #include "breakpoint.h" |
faf5f7ad | 36 | |
34e8f22d | 37 | #include "arm-tdep.h" |
cb587d83 | 38 | #include "arm-linux-tdep.h" |
0670c0aa | 39 | #include "glibc-tdep.h" |
a52e6aac | 40 | |
8e9d1a24 DJ |
41 | #include "gdb_string.h" |
42 | ||
cb587d83 DJ |
43 | extern int arm_apcs_32; |
44 | ||
fdf39c9a RE |
45 | /* Under ARM GNU/Linux the traditional way of performing a breakpoint |
46 | is to execute a particular software interrupt, rather than use a | |
47 | particular undefined instruction to provoke a trap. Upon exection | |
48 | of the software interrupt the kernel stops the inferior with a | |
498b1f87 | 49 | SIGTRAP, and wakes the debugger. */ |
66e810cd | 50 | |
2ef47cd0 DJ |
51 | static const char arm_linux_arm_le_breakpoint[] = { 0x01, 0x00, 0x9f, 0xef }; |
52 | ||
53 | static const char arm_linux_arm_be_breakpoint[] = { 0xef, 0x9f, 0x00, 0x01 }; | |
66e810cd | 54 | |
c75a2cc8 DJ |
55 | /* However, the EABI syscall interface (new in Nov. 2005) does not look at |
56 | the operand of the swi if old-ABI compatibility is disabled. Therefore, | |
57 | use an undefined instruction instead. This is supported as of kernel | |
58 | version 2.5.70 (May 2003), so should be a safe assumption for EABI | |
59 | binaries. */ | |
60 | ||
61 | static const char eabi_linux_arm_le_breakpoint[] = { 0xf0, 0x01, 0xf0, 0xe7 }; | |
62 | ||
63 | static const char eabi_linux_arm_be_breakpoint[] = { 0xe7, 0xf0, 0x01, 0xf0 }; | |
64 | ||
65 | /* All the kernels which support Thumb support using a specific undefined | |
66 | instruction for the Thumb breakpoint. */ | |
67 | ||
498b1f87 DJ |
68 | static const char arm_linux_thumb_be_breakpoint[] = {0xde, 0x01}; |
69 | ||
70 | static const char arm_linux_thumb_le_breakpoint[] = {0x01, 0xde}; | |
71 | ||
9df628e0 | 72 | /* Description of the longjmp buffer. */ |
7a5ea0d4 | 73 | #define ARM_LINUX_JB_ELEMENT_SIZE INT_REGISTER_SIZE |
a6cdd8c5 | 74 | #define ARM_LINUX_JB_PC 21 |
faf5f7ad | 75 | |
f38e884d | 76 | /* |
fdf39c9a RE |
77 | Dynamic Linking on ARM GNU/Linux |
78 | -------------------------------- | |
f38e884d SB |
79 | |
80 | Note: PLT = procedure linkage table | |
81 | GOT = global offset table | |
82 | ||
83 | As much as possible, ELF dynamic linking defers the resolution of | |
84 | jump/call addresses until the last minute. The technique used is | |
85 | inspired by the i386 ELF design, and is based on the following | |
86 | constraints. | |
87 | ||
88 | 1) The calling technique should not force a change in the assembly | |
89 | code produced for apps; it MAY cause changes in the way assembly | |
90 | code is produced for position independent code (i.e. shared | |
91 | libraries). | |
92 | ||
93 | 2) The technique must be such that all executable areas must not be | |
94 | modified; and any modified areas must not be executed. | |
95 | ||
96 | To do this, there are three steps involved in a typical jump: | |
97 | ||
98 | 1) in the code | |
99 | 2) through the PLT | |
100 | 3) using a pointer from the GOT | |
101 | ||
102 | When the executable or library is first loaded, each GOT entry is | |
103 | initialized to point to the code which implements dynamic name | |
104 | resolution and code finding. This is normally a function in the | |
fdf39c9a RE |
105 | program interpreter (on ARM GNU/Linux this is usually |
106 | ld-linux.so.2, but it does not have to be). On the first | |
107 | invocation, the function is located and the GOT entry is replaced | |
108 | with the real function address. Subsequent calls go through steps | |
109 | 1, 2 and 3 and end up calling the real code. | |
f38e884d SB |
110 | |
111 | 1) In the code: | |
112 | ||
113 | b function_call | |
114 | bl function_call | |
115 | ||
116 | This is typical ARM code using the 26 bit relative branch or branch | |
117 | and link instructions. The target of the instruction | |
118 | (function_call is usually the address of the function to be called. | |
119 | In position independent code, the target of the instruction is | |
120 | actually an entry in the PLT when calling functions in a shared | |
121 | library. Note that this call is identical to a normal function | |
122 | call, only the target differs. | |
123 | ||
124 | 2) In the PLT: | |
125 | ||
126 | The PLT is a synthetic area, created by the linker. It exists in | |
127 | both executables and libraries. It is an array of stubs, one per | |
128 | imported function call. It looks like this: | |
129 | ||
130 | PLT[0]: | |
131 | str lr, [sp, #-4]! @push the return address (lr) | |
132 | ldr lr, [pc, #16] @load from 6 words ahead | |
133 | add lr, pc, lr @form an address for GOT[0] | |
134 | ldr pc, [lr, #8]! @jump to the contents of that addr | |
135 | ||
136 | The return address (lr) is pushed on the stack and used for | |
137 | calculations. The load on the second line loads the lr with | |
138 | &GOT[3] - . - 20. The addition on the third leaves: | |
139 | ||
140 | lr = (&GOT[3] - . - 20) + (. + 8) | |
141 | lr = (&GOT[3] - 12) | |
142 | lr = &GOT[0] | |
143 | ||
144 | On the fourth line, the pc and lr are both updated, so that: | |
145 | ||
146 | pc = GOT[2] | |
147 | lr = &GOT[0] + 8 | |
148 | = &GOT[2] | |
149 | ||
150 | NOTE: PLT[0] borrows an offset .word from PLT[1]. This is a little | |
151 | "tight", but allows us to keep all the PLT entries the same size. | |
152 | ||
153 | PLT[n+1]: | |
154 | ldr ip, [pc, #4] @load offset from gotoff | |
155 | add ip, pc, ip @add the offset to the pc | |
156 | ldr pc, [ip] @jump to that address | |
157 | gotoff: .word GOT[n+3] - . | |
158 | ||
159 | The load on the first line, gets an offset from the fourth word of | |
160 | the PLT entry. The add on the second line makes ip = &GOT[n+3], | |
161 | which contains either a pointer to PLT[0] (the fixup trampoline) or | |
162 | a pointer to the actual code. | |
163 | ||
164 | 3) In the GOT: | |
165 | ||
166 | The GOT contains helper pointers for both code (PLT) fixups and | |
167 | data fixups. The first 3 entries of the GOT are special. The next | |
168 | M entries (where M is the number of entries in the PLT) belong to | |
169 | the PLT fixups. The next D (all remaining) entries belong to | |
170 | various data fixups. The actual size of the GOT is 3 + M + D. | |
171 | ||
172 | The GOT is also a synthetic area, created by the linker. It exists | |
173 | in both executables and libraries. When the GOT is first | |
174 | initialized , all the GOT entries relating to PLT fixups are | |
175 | pointing to code back at PLT[0]. | |
176 | ||
177 | The special entries in the GOT are: | |
178 | ||
179 | GOT[0] = linked list pointer used by the dynamic loader | |
180 | GOT[1] = pointer to the reloc table for this module | |
181 | GOT[2] = pointer to the fixup/resolver code | |
182 | ||
183 | The first invocation of function call comes through and uses the | |
184 | fixup/resolver code. On the entry to the fixup/resolver code: | |
185 | ||
186 | ip = &GOT[n+3] | |
187 | lr = &GOT[2] | |
188 | stack[0] = return address (lr) of the function call | |
189 | [r0, r1, r2, r3] are still the arguments to the function call | |
190 | ||
191 | This is enough information for the fixup/resolver code to work | |
192 | with. Before the fixup/resolver code returns, it actually calls | |
193 | the requested function and repairs &GOT[n+3]. */ | |
194 | ||
2a451106 KB |
195 | /* The constants below were determined by examining the following files |
196 | in the linux kernel sources: | |
197 | ||
198 | arch/arm/kernel/signal.c | |
199 | - see SWI_SYS_SIGRETURN and SWI_SYS_RT_SIGRETURN | |
200 | include/asm-arm/unistd.h | |
201 | - see __NR_sigreturn, __NR_rt_sigreturn, and __NR_SYSCALL_BASE */ | |
202 | ||
203 | #define ARM_LINUX_SIGRETURN_INSTR 0xef900077 | |
204 | #define ARM_LINUX_RT_SIGRETURN_INSTR 0xef9000ad | |
205 | ||
edfb1a26 DJ |
206 | /* For ARM EABI, the syscall number is not in the SWI instruction |
207 | (instead it is loaded into r7). We recognize the pattern that | |
208 | glibc uses... alternatively, we could arrange to do this by | |
209 | function name, but they are not always exported. */ | |
8e9d1a24 DJ |
210 | #define ARM_SET_R7_SIGRETURN 0xe3a07077 |
211 | #define ARM_SET_R7_RT_SIGRETURN 0xe3a070ad | |
212 | #define ARM_EABI_SYSCALL 0xef000000 | |
2a451106 | 213 | |
8e9d1a24 DJ |
214 | static void |
215 | arm_linux_sigtramp_cache (struct frame_info *next_frame, | |
216 | struct trad_frame_cache *this_cache, | |
217 | CORE_ADDR func, int regs_offset) | |
2a451106 | 218 | { |
8e9d1a24 DJ |
219 | CORE_ADDR sp = frame_unwind_register_unsigned (next_frame, ARM_SP_REGNUM); |
220 | CORE_ADDR base = sp + regs_offset; | |
221 | int i; | |
2a451106 | 222 | |
8e9d1a24 DJ |
223 | for (i = 0; i < 16; i++) |
224 | trad_frame_set_reg_addr (this_cache, i, base + i * 4); | |
2a451106 | 225 | |
8e9d1a24 | 226 | trad_frame_set_reg_addr (this_cache, ARM_PS_REGNUM, base + 16 * 4); |
2a451106 | 227 | |
8e9d1a24 DJ |
228 | /* The VFP or iWMMXt registers may be saved on the stack, but there's |
229 | no reliable way to restore them (yet). */ | |
2a451106 | 230 | |
8e9d1a24 DJ |
231 | /* Save a frame ID. */ |
232 | trad_frame_set_id (this_cache, frame_id_build (sp, func)); | |
233 | } | |
2a451106 | 234 | |
edfb1a26 DJ |
235 | /* There are a couple of different possible stack layouts that |
236 | we need to support. | |
237 | ||
238 | Before version 2.6.18, the kernel used completely independent | |
239 | layouts for non-RT and RT signals. For non-RT signals the stack | |
240 | began directly with a struct sigcontext. For RT signals the stack | |
241 | began with two redundant pointers (to the siginfo and ucontext), | |
242 | and then the siginfo and ucontext. | |
243 | ||
244 | As of version 2.6.18, the non-RT signal frame layout starts with | |
245 | a ucontext and the RT signal frame starts with a siginfo and then | |
246 | a ucontext. Also, the ucontext now has a designated save area | |
247 | for coprocessor registers. | |
248 | ||
249 | For RT signals, it's easy to tell the difference: we look for | |
250 | pinfo, the pointer to the siginfo. If it has the expected | |
251 | value, we have an old layout. If it doesn't, we have the new | |
252 | layout. | |
253 | ||
254 | For non-RT signals, it's a bit harder. We need something in one | |
255 | layout or the other with a recognizable offset and value. We can't | |
256 | use the return trampoline, because ARM usually uses SA_RESTORER, | |
257 | in which case the stack return trampoline is not filled in. | |
258 | We can't use the saved stack pointer, because sigaltstack might | |
259 | be in use. So for now we guess the new layout... */ | |
260 | ||
261 | /* There are three words (trap_no, error_code, oldmask) in | |
262 | struct sigcontext before r0. */ | |
263 | #define ARM_SIGCONTEXT_R0 0xc | |
264 | ||
265 | /* There are five words (uc_flags, uc_link, and three for uc_stack) | |
266 | in the ucontext_t before the sigcontext. */ | |
267 | #define ARM_UCONTEXT_SIGCONTEXT 0x14 | |
268 | ||
269 | /* There are three elements in an rt_sigframe before the ucontext: | |
270 | pinfo, puc, and info. The first two are pointers and the third | |
271 | is a struct siginfo, with size 128 bytes. We could follow puc | |
272 | to the ucontext, but it's simpler to skip the whole thing. */ | |
273 | #define ARM_OLD_RT_SIGFRAME_SIGINFO 0x8 | |
274 | #define ARM_OLD_RT_SIGFRAME_UCONTEXT 0x88 | |
275 | ||
276 | #define ARM_NEW_RT_SIGFRAME_UCONTEXT 0x80 | |
277 | ||
278 | #define ARM_NEW_SIGFRAME_MAGIC 0x5ac3c35a | |
279 | ||
8e9d1a24 DJ |
280 | static void |
281 | arm_linux_sigreturn_init (const struct tramp_frame *self, | |
282 | struct frame_info *next_frame, | |
283 | struct trad_frame_cache *this_cache, | |
284 | CORE_ADDR func) | |
2a451106 | 285 | { |
edfb1a26 DJ |
286 | CORE_ADDR sp = frame_unwind_register_unsigned (next_frame, ARM_SP_REGNUM); |
287 | ULONGEST uc_flags = read_memory_unsigned_integer (sp, 4); | |
288 | ||
289 | if (uc_flags == ARM_NEW_SIGFRAME_MAGIC) | |
290 | arm_linux_sigtramp_cache (next_frame, this_cache, func, | |
291 | ARM_UCONTEXT_SIGCONTEXT | |
292 | + ARM_SIGCONTEXT_R0); | |
293 | else | |
294 | arm_linux_sigtramp_cache (next_frame, this_cache, func, | |
295 | ARM_SIGCONTEXT_R0); | |
8e9d1a24 | 296 | } |
2a451106 | 297 | |
8e9d1a24 DJ |
298 | static void |
299 | arm_linux_rt_sigreturn_init (const struct tramp_frame *self, | |
300 | struct frame_info *next_frame, | |
301 | struct trad_frame_cache *this_cache, | |
302 | CORE_ADDR func) | |
303 | { | |
edfb1a26 DJ |
304 | CORE_ADDR sp = frame_unwind_register_unsigned (next_frame, ARM_SP_REGNUM); |
305 | ULONGEST pinfo = read_memory_unsigned_integer (sp, 4); | |
306 | ||
307 | if (pinfo == sp + ARM_OLD_RT_SIGFRAME_SIGINFO) | |
308 | arm_linux_sigtramp_cache (next_frame, this_cache, func, | |
309 | ARM_OLD_RT_SIGFRAME_UCONTEXT | |
310 | + ARM_UCONTEXT_SIGCONTEXT | |
311 | + ARM_SIGCONTEXT_R0); | |
312 | else | |
313 | arm_linux_sigtramp_cache (next_frame, this_cache, func, | |
314 | ARM_NEW_RT_SIGFRAME_UCONTEXT | |
315 | + ARM_UCONTEXT_SIGCONTEXT | |
316 | + ARM_SIGCONTEXT_R0); | |
2a451106 KB |
317 | } |
318 | ||
8e9d1a24 DJ |
319 | static struct tramp_frame arm_linux_sigreturn_tramp_frame = { |
320 | SIGTRAMP_FRAME, | |
321 | 4, | |
322 | { | |
323 | { ARM_LINUX_SIGRETURN_INSTR, -1 }, | |
324 | { TRAMP_SENTINEL_INSN } | |
325 | }, | |
326 | arm_linux_sigreturn_init | |
327 | }; | |
328 | ||
329 | static struct tramp_frame arm_linux_rt_sigreturn_tramp_frame = { | |
330 | SIGTRAMP_FRAME, | |
331 | 4, | |
332 | { | |
333 | { ARM_LINUX_RT_SIGRETURN_INSTR, -1 }, | |
334 | { TRAMP_SENTINEL_INSN } | |
335 | }, | |
336 | arm_linux_rt_sigreturn_init | |
337 | }; | |
338 | ||
339 | static struct tramp_frame arm_eabi_linux_sigreturn_tramp_frame = { | |
340 | SIGTRAMP_FRAME, | |
341 | 4, | |
342 | { | |
343 | { ARM_SET_R7_SIGRETURN, -1 }, | |
344 | { ARM_EABI_SYSCALL, -1 }, | |
345 | { TRAMP_SENTINEL_INSN } | |
346 | }, | |
347 | arm_linux_sigreturn_init | |
348 | }; | |
349 | ||
350 | static struct tramp_frame arm_eabi_linux_rt_sigreturn_tramp_frame = { | |
351 | SIGTRAMP_FRAME, | |
352 | 4, | |
353 | { | |
354 | { ARM_SET_R7_RT_SIGRETURN, -1 }, | |
355 | { ARM_EABI_SYSCALL, -1 }, | |
356 | { TRAMP_SENTINEL_INSN } | |
357 | }, | |
358 | arm_linux_rt_sigreturn_init | |
359 | }; | |
360 | ||
cb587d83 DJ |
361 | /* Core file and register set support. */ |
362 | ||
363 | #define ARM_LINUX_SIZEOF_GREGSET (18 * INT_REGISTER_SIZE) | |
364 | ||
365 | void | |
366 | arm_linux_supply_gregset (const struct regset *regset, | |
367 | struct regcache *regcache, | |
368 | int regnum, const void *gregs_buf, size_t len) | |
369 | { | |
370 | const gdb_byte *gregs = gregs_buf; | |
371 | int regno; | |
372 | CORE_ADDR reg_pc; | |
373 | gdb_byte pc_buf[INT_REGISTER_SIZE]; | |
374 | ||
375 | for (regno = ARM_A1_REGNUM; regno < ARM_PC_REGNUM; regno++) | |
376 | if (regnum == -1 || regnum == regno) | |
377 | regcache_raw_supply (regcache, regno, | |
378 | gregs + INT_REGISTER_SIZE * regno); | |
379 | ||
380 | if (regnum == ARM_PS_REGNUM || regnum == -1) | |
381 | { | |
382 | if (arm_apcs_32) | |
383 | regcache_raw_supply (regcache, ARM_PS_REGNUM, | |
384 | gregs + INT_REGISTER_SIZE * ARM_CPSR_REGNUM); | |
385 | else | |
386 | regcache_raw_supply (regcache, ARM_PS_REGNUM, | |
387 | gregs + INT_REGISTER_SIZE * ARM_PC_REGNUM); | |
388 | } | |
389 | ||
390 | if (regnum == ARM_PC_REGNUM || regnum == -1) | |
391 | { | |
392 | reg_pc = extract_unsigned_integer (gregs | |
393 | + INT_REGISTER_SIZE * ARM_PC_REGNUM, | |
394 | INT_REGISTER_SIZE); | |
bf6ae464 | 395 | reg_pc = gdbarch_addr_bits_remove (current_gdbarch, reg_pc); |
cb587d83 DJ |
396 | store_unsigned_integer (pc_buf, INT_REGISTER_SIZE, reg_pc); |
397 | regcache_raw_supply (regcache, ARM_PC_REGNUM, pc_buf); | |
398 | } | |
399 | } | |
400 | ||
401 | void | |
402 | arm_linux_collect_gregset (const struct regset *regset, | |
403 | const struct regcache *regcache, | |
404 | int regnum, void *gregs_buf, size_t len) | |
405 | { | |
406 | gdb_byte *gregs = gregs_buf; | |
407 | int regno; | |
408 | ||
409 | for (regno = ARM_A1_REGNUM; regno < ARM_PC_REGNUM; regno++) | |
410 | if (regnum == -1 || regnum == regno) | |
411 | regcache_raw_collect (regcache, regno, | |
412 | gregs + INT_REGISTER_SIZE * regno); | |
413 | ||
414 | if (regnum == ARM_PS_REGNUM || regnum == -1) | |
415 | { | |
416 | if (arm_apcs_32) | |
417 | regcache_raw_collect (regcache, ARM_PS_REGNUM, | |
418 | gregs + INT_REGISTER_SIZE * ARM_CPSR_REGNUM); | |
419 | else | |
420 | regcache_raw_collect (regcache, ARM_PS_REGNUM, | |
421 | gregs + INT_REGISTER_SIZE * ARM_PC_REGNUM); | |
422 | } | |
423 | ||
424 | if (regnum == ARM_PC_REGNUM || regnum == -1) | |
425 | regcache_raw_collect (regcache, ARM_PC_REGNUM, | |
426 | gregs + INT_REGISTER_SIZE * ARM_PC_REGNUM); | |
427 | } | |
428 | ||
429 | /* Support for register format used by the NWFPE FPA emulator. */ | |
430 | ||
431 | #define typeNone 0x00 | |
432 | #define typeSingle 0x01 | |
433 | #define typeDouble 0x02 | |
434 | #define typeExtended 0x03 | |
435 | ||
436 | void | |
437 | supply_nwfpe_register (struct regcache *regcache, int regno, | |
438 | const gdb_byte *regs) | |
439 | { | |
440 | const gdb_byte *reg_data; | |
441 | gdb_byte reg_tag; | |
442 | gdb_byte buf[FP_REGISTER_SIZE]; | |
443 | ||
444 | reg_data = regs + (regno - ARM_F0_REGNUM) * FP_REGISTER_SIZE; | |
445 | reg_tag = regs[(regno - ARM_F0_REGNUM) + NWFPE_TAGS_OFFSET]; | |
446 | memset (buf, 0, FP_REGISTER_SIZE); | |
447 | ||
448 | switch (reg_tag) | |
449 | { | |
450 | case typeSingle: | |
451 | memcpy (buf, reg_data, 4); | |
452 | break; | |
453 | case typeDouble: | |
454 | memcpy (buf, reg_data + 4, 4); | |
455 | memcpy (buf + 4, reg_data, 4); | |
456 | break; | |
457 | case typeExtended: | |
458 | /* We want sign and exponent, then least significant bits, | |
459 | then most significant. NWFPE does sign, most, least. */ | |
460 | memcpy (buf, reg_data, 4); | |
461 | memcpy (buf + 4, reg_data + 8, 4); | |
462 | memcpy (buf + 8, reg_data + 4, 4); | |
463 | break; | |
464 | default: | |
465 | break; | |
466 | } | |
467 | ||
468 | regcache_raw_supply (regcache, regno, buf); | |
469 | } | |
470 | ||
471 | void | |
472 | collect_nwfpe_register (const struct regcache *regcache, int regno, | |
473 | gdb_byte *regs) | |
474 | { | |
475 | gdb_byte *reg_data; | |
476 | gdb_byte reg_tag; | |
477 | gdb_byte buf[FP_REGISTER_SIZE]; | |
478 | ||
479 | regcache_raw_collect (regcache, regno, buf); | |
480 | ||
481 | /* NOTE drow/2006-06-07: This code uses the tag already in the | |
482 | register buffer. I've preserved that when moving the code | |
483 | from the native file to the target file. But this doesn't | |
484 | always make sense. */ | |
485 | ||
486 | reg_data = regs + (regno - ARM_F0_REGNUM) * FP_REGISTER_SIZE; | |
487 | reg_tag = regs[(regno - ARM_F0_REGNUM) + NWFPE_TAGS_OFFSET]; | |
488 | ||
489 | switch (reg_tag) | |
490 | { | |
491 | case typeSingle: | |
492 | memcpy (reg_data, buf, 4); | |
493 | break; | |
494 | case typeDouble: | |
495 | memcpy (reg_data, buf + 4, 4); | |
496 | memcpy (reg_data + 4, buf, 4); | |
497 | break; | |
498 | case typeExtended: | |
499 | memcpy (reg_data, buf, 4); | |
500 | memcpy (reg_data + 4, buf + 8, 4); | |
501 | memcpy (reg_data + 8, buf + 4, 4); | |
502 | break; | |
503 | default: | |
504 | break; | |
505 | } | |
506 | } | |
507 | ||
508 | void | |
509 | arm_linux_supply_nwfpe (const struct regset *regset, | |
510 | struct regcache *regcache, | |
511 | int regnum, const void *regs_buf, size_t len) | |
512 | { | |
513 | const gdb_byte *regs = regs_buf; | |
514 | int regno; | |
515 | ||
516 | if (regnum == ARM_FPS_REGNUM || regnum == -1) | |
517 | regcache_raw_supply (regcache, ARM_FPS_REGNUM, | |
518 | regs + NWFPE_FPSR_OFFSET); | |
519 | ||
520 | for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++) | |
521 | if (regnum == -1 || regnum == regno) | |
522 | supply_nwfpe_register (regcache, regno, regs); | |
523 | } | |
524 | ||
525 | void | |
526 | arm_linux_collect_nwfpe (const struct regset *regset, | |
527 | const struct regcache *regcache, | |
528 | int regnum, void *regs_buf, size_t len) | |
529 | { | |
530 | gdb_byte *regs = regs_buf; | |
531 | int regno; | |
532 | ||
533 | for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++) | |
534 | if (regnum == -1 || regnum == regno) | |
535 | collect_nwfpe_register (regcache, regno, regs); | |
536 | ||
537 | if (regnum == ARM_FPS_REGNUM || regnum == -1) | |
538 | regcache_raw_collect (regcache, ARM_FPS_REGNUM, | |
539 | regs + INT_REGISTER_SIZE * ARM_FPS_REGNUM); | |
540 | } | |
541 | ||
542 | /* Return the appropriate register set for the core section identified | |
543 | by SECT_NAME and SECT_SIZE. */ | |
544 | ||
545 | static const struct regset * | |
546 | arm_linux_regset_from_core_section (struct gdbarch *gdbarch, | |
547 | const char *sect_name, size_t sect_size) | |
548 | { | |
549 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
550 | ||
551 | if (strcmp (sect_name, ".reg") == 0 | |
552 | && sect_size == ARM_LINUX_SIZEOF_GREGSET) | |
553 | { | |
554 | if (tdep->gregset == NULL) | |
555 | tdep->gregset = regset_alloc (gdbarch, arm_linux_supply_gregset, | |
556 | arm_linux_collect_gregset); | |
557 | return tdep->gregset; | |
558 | } | |
559 | ||
560 | if (strcmp (sect_name, ".reg2") == 0 | |
561 | && sect_size == ARM_LINUX_SIZEOF_NWFPE) | |
562 | { | |
563 | if (tdep->fpregset == NULL) | |
564 | tdep->fpregset = regset_alloc (gdbarch, arm_linux_supply_nwfpe, | |
565 | arm_linux_collect_nwfpe); | |
566 | return tdep->fpregset; | |
567 | } | |
568 | ||
569 | return NULL; | |
570 | } | |
571 | ||
daddc3c1 DJ |
572 | /* Insert a single step breakpoint at the next executed instruction. */ |
573 | ||
574 | int | |
575 | arm_linux_software_single_step (struct frame_info *frame) | |
576 | { | |
577 | CORE_ADDR next_pc = arm_get_next_pc (frame, get_frame_pc (frame)); | |
578 | ||
579 | /* The Linux kernel offers some user-mode helpers in a high page. We can | |
580 | not read this page (as of 2.6.23), and even if we could then we couldn't | |
581 | set breakpoints in it, and even if we could then the atomic operations | |
582 | would fail when interrupted. They are all called as functions and return | |
583 | to the address in LR, so step to there instead. */ | |
584 | if (next_pc > 0xffff0000) | |
585 | next_pc = get_frame_register_unsigned (frame, ARM_LR_REGNUM); | |
586 | ||
587 | insert_single_step_breakpoint (next_pc); | |
588 | ||
589 | return 1; | |
590 | } | |
591 | ||
97e03143 RE |
592 | static void |
593 | arm_linux_init_abi (struct gdbarch_info info, | |
594 | struct gdbarch *gdbarch) | |
595 | { | |
596 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
597 | ||
598 | tdep->lowest_pc = 0x8000; | |
2ef47cd0 | 599 | if (info.byte_order == BFD_ENDIAN_BIG) |
498b1f87 | 600 | { |
c75a2cc8 DJ |
601 | if (tdep->arm_abi == ARM_ABI_AAPCS) |
602 | tdep->arm_breakpoint = eabi_linux_arm_be_breakpoint; | |
603 | else | |
604 | tdep->arm_breakpoint = arm_linux_arm_be_breakpoint; | |
498b1f87 DJ |
605 | tdep->thumb_breakpoint = arm_linux_thumb_be_breakpoint; |
606 | } | |
2ef47cd0 | 607 | else |
498b1f87 | 608 | { |
c75a2cc8 DJ |
609 | if (tdep->arm_abi == ARM_ABI_AAPCS) |
610 | tdep->arm_breakpoint = eabi_linux_arm_le_breakpoint; | |
611 | else | |
612 | tdep->arm_breakpoint = arm_linux_arm_le_breakpoint; | |
498b1f87 DJ |
613 | tdep->thumb_breakpoint = arm_linux_thumb_le_breakpoint; |
614 | } | |
66e810cd | 615 | tdep->arm_breakpoint_size = sizeof (arm_linux_arm_le_breakpoint); |
498b1f87 | 616 | tdep->thumb_breakpoint_size = sizeof (arm_linux_thumb_le_breakpoint); |
9df628e0 | 617 | |
28e97307 DJ |
618 | if (tdep->fp_model == ARM_FLOAT_AUTO) |
619 | tdep->fp_model = ARM_FLOAT_FPA; | |
fd50bc42 | 620 | |
a6cdd8c5 RE |
621 | tdep->jb_pc = ARM_LINUX_JB_PC; |
622 | tdep->jb_elt_size = ARM_LINUX_JB_ELEMENT_SIZE; | |
19d3fc80 | 623 | |
7aa1783e | 624 | set_solib_svr4_fetch_link_map_offsets |
76a9d10f | 625 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
7aa1783e | 626 | |
190dce09 | 627 | /* Single stepping. */ |
daddc3c1 | 628 | set_gdbarch_software_single_step (gdbarch, arm_linux_software_single_step); |
190dce09 | 629 | |
0e18d038 | 630 | /* Shared library handling. */ |
0e18d038 | 631 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
bb41a796 | 632 | set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver); |
b2756930 KB |
633 | |
634 | /* Enable TLS support. */ | |
635 | set_gdbarch_fetch_tls_load_module_address (gdbarch, | |
636 | svr4_fetch_objfile_link_map); | |
8e9d1a24 DJ |
637 | |
638 | tramp_frame_prepend_unwinder (gdbarch, | |
639 | &arm_linux_sigreturn_tramp_frame); | |
640 | tramp_frame_prepend_unwinder (gdbarch, | |
641 | &arm_linux_rt_sigreturn_tramp_frame); | |
642 | tramp_frame_prepend_unwinder (gdbarch, | |
643 | &arm_eabi_linux_sigreturn_tramp_frame); | |
644 | tramp_frame_prepend_unwinder (gdbarch, | |
645 | &arm_eabi_linux_rt_sigreturn_tramp_frame); | |
cb587d83 DJ |
646 | |
647 | /* Core file support. */ | |
648 | set_gdbarch_regset_from_core_section (gdbarch, | |
649 | arm_linux_regset_from_core_section); | |
97e03143 RE |
650 | } |
651 | ||
faf5f7ad SB |
652 | void |
653 | _initialize_arm_linux_tdep (void) | |
654 | { | |
05816f70 MK |
655 | gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_LINUX, |
656 | arm_linux_init_abi); | |
faf5f7ad | 657 | } |