1 /***************************************************************************
2 * Copyright (C) 2009 by Marvell Technology Group Ltd. *
3 * Written by Nicolas Pitre <nico@marvell.com> *
5 * Copyright (C) 2010 by Spencer Oliver *
6 * spen@spen-soft.co.uk *
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 *
10 * the Free Software Foundation; either version 2 of the License, or *
11 * (at your option) any later version. *
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. *
18 * You should have received a copy of the GNU General Public License *
19 * along with this program; if not, write to the *
20 * Free Software Foundation, Inc., *
21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
22 ***************************************************************************/
26 * Hold ARM semihosting support.
28 * Semihosting enables code running on an ARM target to use the I/O
29 * facilities on the host computer. The target application must be linked
30 * against a library that forwards operation requests by using the SVC
31 * instruction trapped at the Supervisor Call vector by the debugger.
32 * Details can be found in chapter 8 of DUI0203I_rvct_developer_guide.pdf
42 #include "arm7_9_common.h"
46 #include "arm_semihosting.h"
47 #include <helper/binarybuffer.h>
48 #include <helper/log.h>
51 static int open_modeflags
[12] = {
56 O_WRONLY
| O_CREAT
| O_TRUNC
,
57 O_WRONLY
| O_CREAT
| O_TRUNC
| O_BINARY
,
58 O_RDWR
| O_CREAT
| O_TRUNC
,
59 O_RDWR
| O_CREAT
| O_TRUNC
| O_BINARY
,
60 O_WRONLY
| O_CREAT
| O_APPEND
,
61 O_WRONLY
| O_CREAT
| O_APPEND
| O_BINARY
,
62 O_RDWR
| O_CREAT
| O_APPEND
,
63 O_RDWR
| O_CREAT
| O_APPEND
| O_BINARY
66 static int do_semihosting(struct target
*target
)
68 struct arm
*arm
= target_to_arm(target
);
69 uint32_t r0
= buf_get_u32(arm
->core_cache
->reg_list
[0].value
, 0, 32);
70 uint32_t r1
= buf_get_u32(arm
->core_cache
->reg_list
[1].value
, 0, 32);
75 * TODO: lots of security issues are not considered yet, such as:
76 * - no validation on target provided file descriptors
77 * - no safety checks on opened/deleted/renamed file paths
78 * Beware the target app you use this support with.
80 * TODO: explore mapping requests to GDB's "File-I/O Remote
81 * Protocol Extension" ... when GDB is active.
84 case 0x01: /* SYS_OPEN */
85 retval
= target_read_memory(target
, r1
, 4, 3, params
);
86 if (retval
!= ERROR_OK
)
89 uint32_t a
= target_buffer_get_u32(target
, params
+0);
90 uint32_t m
= target_buffer_get_u32(target
, params
+4);
91 uint32_t l
= target_buffer_get_u32(target
, params
+8);
92 if (l
<= 255 && m
<= 11) {
94 retval
= target_read_memory(target
, a
, 1, l
, fn
);
95 if (retval
!= ERROR_OK
)
98 if (strcmp((char *)fn
, ":tt") == 0) {
100 result
= dup(STDIN_FILENO
);
102 result
= dup(STDOUT_FILENO
);
104 /* cygwin requires the permission setting
105 * otherwise it will fail to reopen a previously
107 result
= open((char *)fn
, open_modeflags
[m
], 0644);
109 arm
->semihosting_errno
= errno
;
112 arm
->semihosting_errno
= EINVAL
;
117 case 0x02: /* SYS_CLOSE */
118 retval
= target_read_memory(target
, r1
, 4, 1, params
);
119 if (retval
!= ERROR_OK
)
122 int fd
= target_buffer_get_u32(target
, params
+0);
124 arm
->semihosting_errno
= errno
;
128 case 0x03: /* SYS_WRITEC */
131 retval
= target_read_memory(target
, r1
, 1, 1, &c
);
132 if (retval
!= ERROR_OK
)
139 case 0x04: /* SYS_WRITE0 */
142 retval
= target_read_memory(target
, r1
++, 1, 1, &c
);
143 if (retval
!= ERROR_OK
)
152 case 0x05: /* SYS_WRITE */
153 retval
= target_read_memory(target
, r1
, 4, 3, params
);
154 if (retval
!= ERROR_OK
)
157 int fd
= target_buffer_get_u32(target
, params
+0);
158 uint32_t a
= target_buffer_get_u32(target
, params
+4);
159 size_t l
= target_buffer_get_u32(target
, params
+8);
160 uint8_t *buf
= malloc(l
);
163 arm
->semihosting_errno
= ENOMEM
;
165 retval
= target_read_buffer(target
, a
, l
, buf
);
166 if (retval
!= ERROR_OK
) {
170 result
= write(fd
, buf
, l
);
171 arm
->semihosting_errno
= errno
;
179 case 0x06: /* SYS_READ */
180 retval
= target_read_memory(target
, r1
, 4, 3, params
);
181 if (retval
!= ERROR_OK
)
184 int fd
= target_buffer_get_u32(target
, params
+0);
185 uint32_t a
= target_buffer_get_u32(target
, params
+4);
186 ssize_t l
= target_buffer_get_u32(target
, params
+8);
187 uint8_t *buf
= malloc(l
);
190 arm
->semihosting_errno
= ENOMEM
;
192 result
= read(fd
, buf
, l
);
193 arm
->semihosting_errno
= errno
;
195 retval
= target_write_buffer(target
, a
, result
, buf
);
196 if (retval
!= ERROR_OK
) {
207 case 0x07: /* SYS_READC */
211 case 0x08: /* SYS_ISERROR */
212 retval
= target_read_memory(target
, r1
, 4, 1, params
);
213 if (retval
!= ERROR_OK
)
215 result
= (target_buffer_get_u32(target
, params
+0) != 0);
218 case 0x09: /* SYS_ISTTY */
219 retval
= target_read_memory(target
, r1
, 4, 1, params
);
220 if (retval
!= ERROR_OK
)
222 result
= isatty(target_buffer_get_u32(target
, params
+0));
225 case 0x0a: /* SYS_SEEK */
226 retval
= target_read_memory(target
, r1
, 4, 2, params
);
227 if (retval
!= ERROR_OK
)
230 int fd
= target_buffer_get_u32(target
, params
+0);
231 off_t pos
= target_buffer_get_u32(target
, params
+4);
232 result
= lseek(fd
, pos
, SEEK_SET
);
233 arm
->semihosting_errno
= errno
;
239 case 0x0c: /* SYS_FLEN */
240 retval
= target_read_memory(target
, r1
, 4, 1, params
);
241 if (retval
!= ERROR_OK
)
244 int fd
= target_buffer_get_u32(target
, params
+0);
246 result
= fstat(fd
, &buf
);
248 arm
->semihosting_errno
= errno
;
252 result
= buf
.st_size
;
256 case 0x0e: /* SYS_REMOVE */
257 retval
= target_read_memory(target
, r1
, 4, 2, params
);
258 if (retval
!= ERROR_OK
)
261 uint32_t a
= target_buffer_get_u32(target
, params
+0);
262 uint32_t l
= target_buffer_get_u32(target
, params
+4);
265 retval
= target_read_memory(target
, a
, 1, l
, fn
);
266 if (retval
!= ERROR_OK
)
269 result
= remove((char *)fn
);
270 arm
->semihosting_errno
= errno
;
273 arm
->semihosting_errno
= EINVAL
;
278 case 0x0f: /* SYS_RENAME */
279 retval
= target_read_memory(target
, r1
, 4, 4, params
);
280 if (retval
!= ERROR_OK
)
283 uint32_t a1
= target_buffer_get_u32(target
, params
+0);
284 uint32_t l1
= target_buffer_get_u32(target
, params
+4);
285 uint32_t a2
= target_buffer_get_u32(target
, params
+8);
286 uint32_t l2
= target_buffer_get_u32(target
, params
+12);
287 if (l1
<= 255 && l2
<= 255) {
288 uint8_t fn1
[256], fn2
[256];
289 retval
= target_read_memory(target
, a1
, 1, l1
, fn1
);
290 if (retval
!= ERROR_OK
)
292 retval
= target_read_memory(target
, a2
, 1, l2
, fn2
);
293 if (retval
!= ERROR_OK
)
297 result
= rename((char *)fn1
, (char *)fn2
);
298 arm
->semihosting_errno
= errno
;
301 arm
->semihosting_errno
= EINVAL
;
306 case 0x11: /* SYS_TIME */
310 case 0x13: /* SYS_ERRNO */
311 result
= arm
->semihosting_errno
;
314 case 0x15: /* SYS_GET_CMDLINE */
315 retval
= target_read_memory(target
, r1
, 4, 2, params
);
316 if (retval
!= ERROR_OK
)
319 uint32_t a
= target_buffer_get_u32(target
, params
+0);
320 uint32_t l
= target_buffer_get_u32(target
, params
+4);
321 char *arg
= "foobar";
322 uint32_t s
= strlen(arg
) + 1;
326 retval
= target_write_buffer(target
, a
, s
, (void *)arg
);
327 if (retval
!= ERROR_OK
)
334 case 0x16: /* SYS_HEAPINFO */
335 retval
= target_read_memory(target
, r1
, 4, 1, params
);
336 if (retval
!= ERROR_OK
)
339 uint32_t a
= target_buffer_get_u32(target
, params
+0);
340 /* tell the remote we have no idea */
341 memset(params
, 0, 4*4);
342 retval
= target_write_memory(target
, a
, 4, 4, params
);
343 if (retval
!= ERROR_OK
)
349 case 0x18: /* angel_SWIreason_ReportException */
351 case 0x20026: /* ADP_Stopped_ApplicationExit */
352 fprintf(stderr
, "semihosting: *** application exited ***\n");
354 case 0x20000: /* ADP_Stopped_BranchThroughZero */
355 case 0x20001: /* ADP_Stopped_UndefinedInstr */
356 case 0x20002: /* ADP_Stopped_SoftwareInterrupt */
357 case 0x20003: /* ADP_Stopped_PrefetchAbort */
358 case 0x20004: /* ADP_Stopped_DataAbort */
359 case 0x20005: /* ADP_Stopped_AddressException */
360 case 0x20006: /* ADP_Stopped_IRQ */
361 case 0x20007: /* ADP_Stopped_FIQ */
362 case 0x20020: /* ADP_Stopped_BreakPoint */
363 case 0x20021: /* ADP_Stopped_WatchPoint */
364 case 0x20022: /* ADP_Stopped_StepComplete */
365 case 0x20023: /* ADP_Stopped_RunTimeErrorUnknown */
366 case 0x20024: /* ADP_Stopped_InternalError */
367 case 0x20025: /* ADP_Stopped_UserInterruption */
368 case 0x20027: /* ADP_Stopped_StackOverflow */
369 case 0x20028: /* ADP_Stopped_DivisionByZero */
370 case 0x20029: /* ADP_Stopped_OSSpecific */
372 fprintf(stderr
, "semihosting: exception %#x\n",
375 return target_call_event_callbacks(target
, TARGET_EVENT_HALTED
);
377 case 0x12: /* SYS_SYSTEM */
378 /* Provide SYS_SYSTEM functionality. Uses the
379 * libc system command, there may be a reason *NOT*
380 * to use this, but as I can't think of one, I
381 * implemented it this way.
383 retval
= target_read_memory(target
, r1
, 4, 2, params
);
384 if (retval
!= ERROR_OK
)
387 uint32_t len
= target_buffer_get_u32(target
, params
+4);
388 uint32_t c_ptr
= target_buffer_get_u32(target
, params
);
392 arm
->semihosting_errno
= EINVAL
;
394 memset(cmd
, 0x0, 256);
395 retval
= target_read_memory(target
, c_ptr
, 1, len
, cmd
);
396 if (retval
!= ERROR_OK
)
399 result
= system((const char *)cmd
);
403 case 0x0d: /* SYS_TMPNAM */
404 case 0x10: /* SYS_CLOCK */
405 case 0x17: /* angel_SWIreason_EnterSVC */
406 case 0x30: /* SYS_ELAPSED */
407 case 0x31: /* SYS_TICKFREQ */
409 fprintf(stderr
, "semihosting: unsupported call %#x\n",
412 arm
->semihosting_errno
= ENOTSUP
;
415 /* resume execution to the original mode */
417 /* REVISIT this looks wrong ... ARM11 and Cortex-A8
418 * should work this way at least sometimes.
420 if (is_arm7_9(target_to_arm7_9(target
))) {
423 /* return value in R0 */
424 buf_set_u32(arm
->core_cache
->reg_list
[0].value
, 0, 32, result
);
425 arm
->core_cache
->reg_list
[0].dirty
= 1;
428 buf_set_u32(arm
->core_cache
->reg_list
[15].value
, 0, 32,
429 buf_get_u32(arm_reg_current(arm
, 14)->value
, 0, 32));
430 arm
->core_cache
->reg_list
[15].dirty
= 1;
432 /* saved PSR --> current PSR */
433 spsr
= buf_get_u32(arm
->spsr
->value
, 0, 32);
435 /* REVISIT should this be arm_set_cpsr(arm, spsr)
436 * instead of a partially unrolled version?
439 buf_set_u32(arm
->cpsr
->value
, 0, 32, spsr
);
440 arm
->cpsr
->dirty
= 1;
441 arm
->core_mode
= spsr
& 0x1f;
443 arm
->core_state
= ARM_STATE_THUMB
;
446 /* resume execution, this will be pc+2 to skip over the
447 * bkpt instruction */
449 /* return result in R0 */
450 buf_set_u32(arm
->core_cache
->reg_list
[0].value
, 0, 32, result
);
451 arm
->core_cache
->reg_list
[0].dirty
= 1;
454 return target_resume(target
, 1, 0, 0, 0);
458 * Checks for and processes an ARM semihosting request. This is meant
459 * to be called when the target is stopped due to a debug mode entry.
460 * If the value 0 is returned then there was nothing to process. A non-zero
461 * return value signifies that a request was processed and the target resumed,
462 * or an error was encountered, in which case the caller must return
465 * @param target Pointer to the ARM target to process. This target must
466 * not represent an ARMv6-M or ARMv7-M processor.
467 * @param retval Pointer to a location where the return code will be stored
468 * @return non-zero value if a request was processed or an error encountered
470 int arm_semihosting(struct target
*target
, int *retval
)
472 struct arm
*arm
= target_to_arm(target
);
473 uint32_t pc
, lr
, spsr
;
476 if (!arm
->is_semihosting
)
479 if (is_arm7_9(target_to_arm7_9(target
))) {
480 if (arm
->core_mode
!= ARM_MODE_SVC
)
483 /* Check for PC == 0x00000008 or 0xffff0008: Supervisor Call vector. */
485 pc
= buf_get_u32(r
->value
, 0, 32);
486 if (pc
!= 0x00000008 && pc
!= 0xffff0008)
489 r
= arm_reg_current(arm
, 14);
490 lr
= buf_get_u32(r
->value
, 0, 32);
492 /* Core-specific code should make sure SPSR is retrieved
493 * when the above checks pass...
495 if (!arm
->spsr
->valid
) {
496 LOG_ERROR("SPSR not valid!");
497 *retval
= ERROR_FAIL
;
501 spsr
= buf_get_u32(arm
->spsr
->value
, 0, 32);
503 /* check instruction that triggered this trap */
504 if (spsr
& (1 << 5)) {
505 /* was in Thumb (or ThumbEE) mode */
509 *retval
= target_read_memory(target
, lr
-2, 2, 1, insn_buf
);
510 if (*retval
!= ERROR_OK
)
512 insn
= target_buffer_get_u16(target
, insn_buf
);
517 } else if (spsr
& (1 << 24)) {
518 /* was in Jazelle mode */
521 /* was in ARM mode */
525 *retval
= target_read_memory(target
, lr
-4, 4, 1, insn_buf
);
526 if (*retval
!= ERROR_OK
)
528 insn
= target_buffer_get_u32(target
, insn_buf
);
531 if (insn
!= 0xEF123456)
534 } else if (is_armv7m(target_to_armv7m(target
))) {
537 if (target
->debug_reason
!= DBG_REASON_BREAKPOINT
)
541 pc
= buf_get_u32(r
->value
, 0, 32);
544 *retval
= target_read_u16(target
, pc
, &insn
);
545 if (*retval
!= ERROR_OK
)
552 LOG_ERROR("Unsupported semi-hosting Target");
556 *retval
= do_semihosting(target
);