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1 /*
2 * Semihosting support for systems modeled on the Arm "Angel"
3 * semihosting syscalls design. This includes Arm and RISC-V processors
4 *
5 * Copyright (c) 2005, 2007 CodeSourcery.
6 * Copyright (c) 2019 Linaro
7 * Written by Paul Brook.
8 *
9 * Copyright © 2020 by Keith Packard <keithp@keithp.com>
10 * Adapted for systems other than ARM, including RISC-V, by Keith Packard
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, see <http://www.gnu.org/licenses/>.
24 *
25 * ARM Semihosting is documented in:
26 * Semihosting for AArch32 and AArch64 Release 2.0
27 * https://github.com/ARM-software/abi-aa/blob/main/semihosting/semihosting.rst
28 *
29 * RISC-V Semihosting is documented in:
30 * RISC-V Semihosting
31 * https://github.com/riscv/riscv-semihosting-spec/blob/main/riscv-semihosting-spec.adoc
32 */
33
34 #include "qemu/osdep.h"
35 #include "qemu/timer.h"
36 #include "exec/gdbstub.h"
37 #include "gdbstub/syscalls.h"
38 #include "semihosting/semihost.h"
39 #include "semihosting/console.h"
40 #include "semihosting/common-semi.h"
41 #include "semihosting/guestfd.h"
42 #include "semihosting/syscalls.h"
43
44 #ifdef CONFIG_USER_ONLY
45 #include "qemu.h"
46
47 #define COMMON_SEMI_HEAP_SIZE (128 * 1024 * 1024)
48 #else
49 #include "qemu/cutils.h"
50 #include "hw/core/loader.h"
51 #include "hw/core/boards.h"
52 #endif
53
54 #define TARGET_SYS_OPEN 0x01
55 #define TARGET_SYS_CLOSE 0x02
56 #define TARGET_SYS_WRITEC 0x03
57 #define TARGET_SYS_WRITE0 0x04
58 #define TARGET_SYS_WRITE 0x05
59 #define TARGET_SYS_READ 0x06
60 #define TARGET_SYS_READC 0x07
61 #define TARGET_SYS_ISERROR 0x08
62 #define TARGET_SYS_ISTTY 0x09
63 #define TARGET_SYS_SEEK 0x0a
64 #define TARGET_SYS_FLEN 0x0c
65 #define TARGET_SYS_TMPNAM 0x0d
66 #define TARGET_SYS_REMOVE 0x0e
67 #define TARGET_SYS_RENAME 0x0f
68 #define TARGET_SYS_CLOCK 0x10
69 #define TARGET_SYS_TIME 0x11
70 #define TARGET_SYS_SYSTEM 0x12
71 #define TARGET_SYS_ERRNO 0x13
72 #define TARGET_SYS_GET_CMDLINE 0x15
73 #define TARGET_SYS_HEAPINFO 0x16
74 #define TARGET_SYS_EXIT 0x18
75 #define TARGET_SYS_SYNCCACHE 0x19
76 #define TARGET_SYS_EXIT_EXTENDED 0x20
77 #define TARGET_SYS_ELAPSED 0x30
78 #define TARGET_SYS_TICKFREQ 0x31
79
80 /* ADP_Stopped_ApplicationExit is used for exit(0),
81 * anything else is implemented as exit(1) */
82 #define ADP_Stopped_ApplicationExit (0x20026)
83
84 #ifndef O_BINARY
85 #define O_BINARY 0
86 #endif
87
88 static int gdb_open_modeflags[12] = {
89 GDB_O_RDONLY,
90 GDB_O_RDONLY,
91 GDB_O_RDWR,
92 GDB_O_RDWR,
93 GDB_O_WRONLY | GDB_O_CREAT | GDB_O_TRUNC,
94 GDB_O_WRONLY | GDB_O_CREAT | GDB_O_TRUNC,
95 GDB_O_RDWR | GDB_O_CREAT | GDB_O_TRUNC,
96 GDB_O_RDWR | GDB_O_CREAT | GDB_O_TRUNC,
97 GDB_O_WRONLY | GDB_O_CREAT | GDB_O_APPEND,
98 GDB_O_WRONLY | GDB_O_CREAT | GDB_O_APPEND,
99 GDB_O_RDWR | GDB_O_CREAT | GDB_O_APPEND,
100 GDB_O_RDWR | GDB_O_CREAT | GDB_O_APPEND,
101 };
102
103 /*
104 * For ARM semihosting, we have a separate structure for routing
105 * data for the console which is outside the guest fd address space.
106 */
107 static GuestFD console_in_gf;
108 static GuestFD console_out_gf;
109
110 #ifndef CONFIG_USER_ONLY
111
112 /**
113 * common_semi_find_bases: find information about ram and heap base
114 *
115 * This function attempts to provide meaningful numbers for RAM and
116 * HEAP base addresses. The rambase is simply the lowest addressable
117 * RAM position. For the heapbase we ask the loader to scan the
118 * address space and the largest available gap by querying the "ROM"
119 * regions.
120 *
121 * Returns: a structure with the numbers we need.
122 */
123
124 typedef struct LayoutInfo {
125 vaddr rambase;
126 size_t ramsize;
127 hwaddr heapbase;
128 hwaddr heaplimit;
129 } LayoutInfo;
130
131 static bool find_ram_cb(Int128 start, Int128 len, const MemoryRegion *mr,
132 hwaddr offset_in_region, void *opaque)
133 {
134 LayoutInfo *info = (LayoutInfo *) opaque;
135 uint64_t size = int128_get64(len);
136
137 if (!mr->ram || mr->readonly) {
138 return false;
139 }
140
141 if (size > info->ramsize) {
142 info->rambase = int128_get64(start);
143 info->ramsize = size;
144 }
145
146 /* search exhaustively for largest RAM */
147 return false;
148 }
149
150 static LayoutInfo common_semi_find_bases(CPUState *cs)
151 {
152 FlatView *fv;
153 LayoutInfo info = { 0, 0, 0, 0 };
154
155 RCU_READ_LOCK_GUARD();
156
157 fv = address_space_to_flatview(cs->as);
158 flatview_for_each_range(fv, find_ram_cb, &info);
159
160 /*
161 * If we have found the RAM lets iterate through the ROM blobs to
162 * work out the best place for the remainder of RAM and split it
163 * equally between stack and heap.
164 */
165 if (info.rambase || info.ramsize > 0) {
166 RomGap gap = rom_find_largest_gap_between(info.rambase, info.ramsize);
167 info.heapbase = gap.base;
168 info.heaplimit = gap.base + gap.size;
169 }
170
171 return info;
172 }
173
174 #endif
175
176 #include "semihosting/common-semi.h"
177
178 /*
179 * Read the input value from the argument block; fail the semihosting
180 * call if the memory read fails. Eventually we could use a generic
181 * CPUState helper function here.
182 * Note that GET_ARG() handles memory access errors by jumping to
183 * do_fault, so must be used as the first thing done in handling a
184 * semihosting call, to avoid accidentally leaking allocated resources.
185 * SET_ARG(), since it unavoidably happens late, instead returns an
186 * error indication (0 on success, non-0 for error) which the caller
187 * should check.
188 */
189
190 #define GET_ARG(n) do { \
191 if (is_64bit_semihosting(env)) { \
192 if (get_user_u64(arg ## n, args + (n) * 8)) { \
193 goto do_fault; \
194 } \
195 } else { \
196 if (get_user_u32(arg ## n, args + (n) * 4)) { \
197 goto do_fault; \
198 } \
199 } \
200 } while (0)
201
202 #define SET_ARG(n, val) \
203 (is_64bit_semihosting(env) ? \
204 put_user_u64(val, args + (n) * 8) : \
205 put_user_u32(val, args + (n) * 4))
206
207
208 /*
209 * The semihosting API has no concept of its errno being thread-safe,
210 * as the API design predates SMP CPUs and was intended as a simple
211 * real-hardware set of debug functionality. For QEMU, we make the
212 * errno be per-thread in linux-user mode; in system-mode it is a simple
213 * global, and we assume that the guest takes care of avoiding any races.
214 */
215 #ifndef CONFIG_USER_ONLY
216 static uint64_t syscall_err;
217
218 #include "semihosting/uaccess.h"
219 #endif
220
221 static inline uint32_t get_swi_errno(CPUState *cs)
222 {
223 #ifdef CONFIG_USER_ONLY
224 TaskState *ts = get_task_state(cs);
225
226 return ts->swi_errno;
227 #else
228 return syscall_err;
229 #endif
230 }
231
232 static void common_semi_cb(CPUState *cs, uint64_t ret, int err)
233 {
234 if (err) {
235 #ifdef CONFIG_USER_ONLY
236 TaskState *ts = get_task_state(cs);
237 ts->swi_errno = err;
238 #else
239 syscall_err = err;
240 #endif
241 }
242 common_semi_set_ret(cs, ret);
243 }
244
245 /*
246 * Use 0xdeadbeef as the return value when there isn't a defined
247 * return value for the call.
248 */
249 static void common_semi_dead_cb(CPUState *cs, uint64_t ret, int err)
250 {
251 common_semi_set_ret(cs, 0xdeadbeef);
252 }
253
254 /*
255 * SYS_READ and SYS_WRITE always return the number of bytes not read/written.
256 * There is no error condition, other than returning the original length.
257 */
258 static void common_semi_rw_cb(CPUState *cs, uint64_t ret, int err)
259 {
260 /* Recover the original length from the third argument. */
261 CPUArchState *env G_GNUC_UNUSED = cpu_env(cs);
262 uint64_t args = common_semi_arg(cs, 1);
263 uint64_t arg2;
264 GET_ARG(2);
265
266 if (err) {
267 do_fault:
268 ret = 0; /* error: no bytes transmitted */
269 }
270 common_semi_set_ret(cs, arg2 - ret);
271 }
272
273 /*
274 * Convert from Posix ret+errno to Arm SYS_ISTTY return values.
275 * With gdbstub, err is only ever set for protocol errors to EIO.
276 */
277 static void common_semi_istty_cb(CPUState *cs, uint64_t ret, int err)
278 {
279 if (err) {
280 ret = (err == ENOTTY ? 0 : -1);
281 }
282 common_semi_cb(cs, ret, err);
283 }
284
285 /*
286 * SYS_SEEK returns 0 on success, not the resulting offset.
287 */
288 static void common_semi_seek_cb(CPUState *cs, uint64_t ret, int err)
289 {
290 if (!err) {
291 ret = 0;
292 }
293 common_semi_cb(cs, ret, err);
294 }
295
296 /*
297 * Return an address in target memory of 64 bytes where the remote
298 * gdb should write its stat struct. (The format of this structure
299 * is defined by GDB's remote protocol and is not target-specific.)
300 * We put this on the guest's stack just below SP.
301 */
302 static uint64_t common_semi_flen_buf(CPUState *cs)
303 {
304 vaddr sp = common_semi_stack_bottom(cs);
305 return sp - 64;
306 }
307
308 static void
309 common_semi_flen_fstat_cb(CPUState *cs, uint64_t ret, int err)
310 {
311 if (!err) {
312 /* The size is always stored in big-endian order, extract the value. */
313 uint64_t size;
314 if (cpu_memory_rw_debug(cs, common_semi_flen_buf(cs) +
315 offsetof(struct gdb_stat, gdb_st_size),
316 &size, 8, 0)) {
317 ret = -1, err = EFAULT;
318 } else {
319 ret = be64_to_cpu(size);
320 }
321 }
322 common_semi_cb(cs, ret, err);
323 }
324
325 static void
326 common_semi_readc_cb(CPUState *cs, uint64_t ret, int err)
327 {
328 if (!err) {
329 CPUArchState *env G_GNUC_UNUSED = cpu_env(cs);
330 uint8_t ch;
331
332 if (get_user_u8(ch, common_semi_stack_bottom(cs) - 1)) {
333 ret = -1, err = EFAULT;
334 } else {
335 ret = ch;
336 }
337 }
338 common_semi_cb(cs, ret, err);
339 }
340
341 #define SHFB_MAGIC_0 0x53
342 #define SHFB_MAGIC_1 0x48
343 #define SHFB_MAGIC_2 0x46
344 #define SHFB_MAGIC_3 0x42
345
346 /* Feature bits reportable in feature byte 0 */
347 #define SH_EXT_EXIT_EXTENDED (1 << 0)
348 #define SH_EXT_STDOUT_STDERR (1 << 1)
349
350 static const uint8_t featurefile_data[] = {
351 SHFB_MAGIC_0,
352 SHFB_MAGIC_1,
353 SHFB_MAGIC_2,
354 SHFB_MAGIC_3,
355 SH_EXT_EXIT_EXTENDED | SH_EXT_STDOUT_STDERR, /* Feature byte 0 */
356 };
357
358 bool semihosting_arm_compatible(void)
359 {
360 return true;
361 }
362
363 void semihosting_arm_compatible_init(void)
364 {
365 /* For ARM-compat, the console is in a separate namespace. */
366 if (use_gdb_syscalls()) {
367 console_in_gf.type = GuestFDGDB;
368 console_in_gf.hostfd = 0;
369 console_out_gf.type = GuestFDGDB;
370 console_out_gf.hostfd = 2;
371 } else {
372 console_in_gf.type = GuestFDConsole;
373 console_out_gf.type = GuestFDConsole;
374 }
375 }
376
377 /*
378 * Do a semihosting call.
379 *
380 * The specification always says that the "return register" either
381 * returns a specific value or is corrupted, so we don't need to
382 * report to our caller whether we are returning a value or trying to
383 * leave the register unchanged.
384 */
385 void do_common_semihosting(CPUState *cs)
386 {
387 CPUArchState *env = cpu_env(cs);
388 uint64_t args;
389 uint64_t arg0, arg1, arg2, arg3;
390 uint64_t ul_ret;
391 char * s;
392 int nr;
393 int64_t elapsed;
394
395 nr = common_semi_arg(cs, 0) & 0xffffffffU;
396 args = common_semi_arg(cs, 1);
397
398 switch (nr) {
399 case TARGET_SYS_OPEN:
400 {
401 int ret, err = 0;
402 int hostfd;
403
404 GET_ARG(0);
405 GET_ARG(1);
406 GET_ARG(2);
407 s = lock_user_string(arg0);
408 if (!s) {
409 goto do_fault;
410 }
411 if (arg1 >= 12) {
412 unlock_user(s, arg0, 0);
413 common_semi_cb(cs, -1, EINVAL);
414 break;
415 }
416
417 if (strcmp(s, ":tt") == 0) {
418 /*
419 * We implement SH_EXT_STDOUT_STDERR, so:
420 * open for read == stdin
421 * open for write == stdout
422 * open for append == stderr
423 */
424 if (arg1 < 4) {
425 hostfd = STDIN_FILENO;
426 } else if (arg1 < 8) {
427 hostfd = STDOUT_FILENO;
428 } else {
429 hostfd = STDERR_FILENO;
430 }
431 ret = alloc_guestfd();
432 associate_guestfd(ret, hostfd);
433 } else if (strcmp(s, ":semihosting-features") == 0) {
434 /* We must fail opens for modes other than 0 ('r') or 1 ('rb') */
435 if (arg1 != 0 && arg1 != 1) {
436 ret = -1;
437 err = EACCES;
438 } else {
439 ret = alloc_guestfd();
440 staticfile_guestfd(ret, featurefile_data,
441 sizeof(featurefile_data));
442 }
443 } else {
444 unlock_user(s, arg0, 0);
445 semihost_sys_open(cs, common_semi_cb, arg0, arg2 + 1,
446 gdb_open_modeflags[arg1], 0644);
447 break;
448 }
449 unlock_user(s, arg0, 0);
450 common_semi_cb(cs, ret, err);
451 break;
452 }
453
454 case TARGET_SYS_CLOSE:
455 GET_ARG(0);
456 semihost_sys_close(cs, common_semi_cb, arg0);
457 break;
458
459 case TARGET_SYS_WRITEC:
460 /*
461 * FIXME: the byte to be written is in a uint64_t slot,
462 * which means this is wrong for a big-endian guest.
463 */
464 semihost_sys_write_gf(cs, common_semi_dead_cb,
465 &console_out_gf, args, 1);
466 break;
467
468 case TARGET_SYS_WRITE0:
469 {
470 ssize_t len = target_strlen(args);
471 if (len < 0) {
472 common_semi_dead_cb(cs, -1, EFAULT);
473 } else {
474 semihost_sys_write_gf(cs, common_semi_dead_cb,
475 &console_out_gf, args, len);
476 }
477 }
478 break;
479
480 case TARGET_SYS_WRITE:
481 GET_ARG(0);
482 GET_ARG(1);
483 GET_ARG(2);
484 semihost_sys_write(cs, common_semi_rw_cb, arg0, arg1, arg2);
485 break;
486
487 case TARGET_SYS_READ:
488 GET_ARG(0);
489 GET_ARG(1);
490 GET_ARG(2);
491 semihost_sys_read(cs, common_semi_rw_cb, arg0, arg1, arg2);
492 break;
493
494 case TARGET_SYS_READC:
495 semihost_sys_read_gf(cs, common_semi_readc_cb, &console_in_gf,
496 common_semi_stack_bottom(cs) - 1, 1);
497 break;
498
499 case TARGET_SYS_ISERROR:
500 {
501 GET_ARG(0);
502 bool ret = is_64bit_semihosting(env) ?
503 (int64_t)arg0 < 0 : (int32_t)arg0 < 0;
504 common_semi_set_ret(cs, ret);
505 break;
506 }
507 case TARGET_SYS_ISTTY:
508 GET_ARG(0);
509 semihost_sys_isatty(cs, common_semi_istty_cb, arg0);
510 break;
511
512 case TARGET_SYS_SEEK:
513 GET_ARG(0);
514 GET_ARG(1);
515 semihost_sys_lseek(cs, common_semi_seek_cb, arg0, arg1, GDB_SEEK_SET);
516 break;
517
518 case TARGET_SYS_FLEN:
519 GET_ARG(0);
520 semihost_sys_flen(cs, common_semi_flen_fstat_cb, common_semi_cb,
521 arg0, common_semi_flen_buf(cs));
522 break;
523
524 case TARGET_SYS_TMPNAM:
525 {
526 int len;
527 char *p;
528
529 GET_ARG(0);
530 GET_ARG(1);
531 GET_ARG(2);
532 len = asprintf(&s, "%s/qemu-%x%02x", g_get_tmp_dir(),
533 getpid(), (int)arg1 & 0xff);
534 if (len < 0) {
535 common_semi_set_ret(cs, -1);
536 break;
537 }
538
539 /* Allow for trailing NUL */
540 len++;
541 /* Make sure there's enough space in the buffer */
542 if (len > arg2) {
543 free(s);
544 common_semi_set_ret(cs, -1);
545 break;
546 }
547 p = lock_user(VERIFY_WRITE, arg0, len, 0);
548 if (!p) {
549 free(s);
550 goto do_fault;
551 }
552 memcpy(p, s, len);
553 unlock_user(p, arg0, len);
554 free(s);
555 common_semi_set_ret(cs, 0);
556 break;
557 }
558
559 case TARGET_SYS_REMOVE:
560 GET_ARG(0);
561 GET_ARG(1);
562 semihost_sys_remove(cs, common_semi_cb, arg0, arg1 + 1);
563 break;
564
565 case TARGET_SYS_RENAME:
566 GET_ARG(0);
567 GET_ARG(1);
568 GET_ARG(2);
569 GET_ARG(3);
570 semihost_sys_rename(cs, common_semi_cb, arg0, arg1 + 1, arg2, arg3 + 1);
571 break;
572
573 case TARGET_SYS_CLOCK:
574 common_semi_set_ret(cs, clock() / (CLOCKS_PER_SEC / 100));
575 break;
576
577 case TARGET_SYS_TIME:
578 ul_ret = time(NULL);
579 common_semi_cb(cs, ul_ret, ul_ret == -1 ? errno : 0);
580 break;
581
582 case TARGET_SYS_SYSTEM:
583 GET_ARG(0);
584 GET_ARG(1);
585 semihost_sys_system(cs, common_semi_cb, arg0, arg1 + 1);
586 break;
587
588 case TARGET_SYS_ERRNO:
589 common_semi_set_ret(cs, get_swi_errno(cs));
590 break;
591
592 case TARGET_SYS_GET_CMDLINE:
593 {
594 /* Build a command-line from the original argv.
595 *
596 * The inputs are:
597 * * arg0, pointer to a buffer of at least the size
598 * specified in arg1.
599 * * arg1, size of the buffer pointed to by arg0 in
600 * bytes.
601 *
602 * The outputs are:
603 * * arg0, pointer to null-terminated string of the
604 * command line.
605 * * arg1, length of the string pointed to by arg0.
606 */
607
608 char *output_buffer;
609 size_t input_size;
610 size_t output_size;
611 int status = 0;
612 #if !defined(CONFIG_USER_ONLY)
613 const char *cmdline;
614 #else
615 TaskState *ts = get_task_state(cs);
616 #endif
617 GET_ARG(0);
618 GET_ARG(1);
619 input_size = arg1;
620 /* Compute the size of the output string. */
621 #if !defined(CONFIG_USER_ONLY)
622 cmdline = semihosting_get_cmdline();
623 if (cmdline == NULL) {
624 cmdline = ""; /* Default to an empty line. */
625 }
626 output_size = strlen(cmdline) + 1; /* Count terminating 0. */
627 #else
628 unsigned int i;
629
630 output_size = ts->info->env_strings - ts->info->arg_strings;
631 if (!output_size) {
632 /*
633 * We special-case the "empty command line" case (argc==0).
634 * Just provide the terminating 0.
635 */
636 output_size = 1;
637 }
638 #endif
639
640 if (output_size > input_size) {
641 /* Not enough space to store command-line arguments. */
642 common_semi_cb(cs, -1, E2BIG);
643 break;
644 }
645
646 /* Adjust the command-line length. */
647 if (SET_ARG(1, output_size - 1)) {
648 /* Couldn't write back to argument block */
649 goto do_fault;
650 }
651
652 /* Lock the buffer on the ARM side. */
653 output_buffer = lock_user(VERIFY_WRITE, arg0, output_size, 0);
654 if (!output_buffer) {
655 goto do_fault;
656 }
657
658 /* Copy the command-line arguments. */
659 #if !defined(CONFIG_USER_ONLY)
660 pstrcpy(output_buffer, output_size, cmdline);
661 #else
662 if (output_size == 1) {
663 /* Empty command-line. */
664 output_buffer[0] = '\0';
665 goto out;
666 }
667
668 if (copy_from_user(output_buffer, ts->info->arg_strings,
669 output_size)) {
670 unlock_user(output_buffer, arg0, 0);
671 goto do_fault;
672 }
673
674 /* Separate arguments by white spaces. */
675 for (i = 0; i < output_size - 1; i++) {
676 if (output_buffer[i] == 0) {
677 output_buffer[i] = ' ';
678 }
679 }
680 out:
681 #endif
682 /* Unlock the buffer on the ARM side. */
683 unlock_user(output_buffer, arg0, output_size);
684 common_semi_cb(cs, status, 0);
685 }
686 break;
687
688 case TARGET_SYS_HEAPINFO:
689 {
690 uint64_t retvals[4];
691 int i;
692 #ifdef CONFIG_USER_ONLY
693 TaskState *ts = get_task_state(cs);
694 static abi_ulong heapbase, heaplimit;
695 #else
696 LayoutInfo info = common_semi_find_bases(cs);
697 #endif
698
699 GET_ARG(0);
700
701 #ifdef CONFIG_USER_ONLY
702 /*
703 * Some C libraries assume the heap immediately follows .bss, so
704 * allocate it using sbrk.
705 */
706 if (!heaplimit) {
707 heapbase = do_brk(0);
708 /* Try a big heap, and reduce the size if that fails. */
709 for (abi_ulong size = COMMON_SEMI_HEAP_SIZE; ; size >>= 1) {
710 abi_ulong limit = heapbase + size;
711 abi_ulong ret = do_brk(limit);
712 if (ret >= limit) {
713 heaplimit = limit;
714 break;
715 }
716 }
717 }
718 retvals[0] = heapbase;
719 retvals[1] = heaplimit;
720 /*
721 * Note that semihosting is *not* thread aware.
722 * Always return the stack base of the main thread.
723 */
724 retvals[2] = ts->info->start_stack;
725 retvals[3] = 0; /* Stack limit. */
726 #else
727 retvals[0] = info.heapbase; /* Heap Base */
728 retvals[1] = info.heaplimit; /* Heap Limit */
729 retvals[2] = info.heaplimit; /* Stack base */
730 retvals[3] = info.heapbase; /* Stack limit. */
731 #endif
732
733 for (i = 0; i < ARRAY_SIZE(retvals); i++) {
734 bool fail;
735
736 if (is_64bit_semihosting(env)) {
737 fail = put_user_u64(retvals[i], arg0 + i * 8);
738 } else {
739 fail = put_user_u32(retvals[i], arg0 + i * 4);
740 }
741
742 if (fail) {
743 /* Couldn't write back to argument block */
744 goto do_fault;
745 }
746 }
747 common_semi_set_ret(cs, 0);
748 }
749 break;
750
751 case TARGET_SYS_EXIT:
752 case TARGET_SYS_EXIT_EXTENDED:
753 {
754 uint32_t ret;
755
756 if (nr == TARGET_SYS_EXIT_EXTENDED ||
757 common_semi_sys_exit_is_extended(cs)) {
758 /*
759 * The A64 version of SYS_EXIT takes a parameter block,
760 * so the application-exit type can return a subcode which
761 * is the exit status code from the application.
762 * SYS_EXIT_EXTENDED is an a new-in-v2.0 optional function
763 * which allows A32/T32 guests to also provide a status code.
764 */
765 GET_ARG(0);
766 GET_ARG(1);
767
768 if (arg0 == ADP_Stopped_ApplicationExit) {
769 ret = arg1;
770 } else {
771 ret = 1;
772 }
773 } else {
774 /*
775 * The A32/T32 version of SYS_EXIT specifies only
776 * Stopped_ApplicationExit as normal exit, but does not
777 * allow the guest to specify the exit status code.
778 * Everything else is considered an error.
779 */
780 ret = (args == ADP_Stopped_ApplicationExit) ? 0 : 1;
781 }
782 gdb_exit(ret);
783 exit(ret);
784 }
785
786 case TARGET_SYS_ELAPSED:
787 elapsed = get_clock() - clock_start;
788 if (is_64bit_semihosting(env)) {
789 if (SET_ARG(0, elapsed)) {
790 goto do_fault;
791 }
792 } else {
793 if (SET_ARG(0, (uint32_t) elapsed) ||
794 SET_ARG(1, (uint32_t) (elapsed >> 32))) {
795 goto do_fault;
796 }
797 }
798 common_semi_set_ret(cs, 0);
799 break;
800
801 case TARGET_SYS_TICKFREQ:
802 /* qemu always uses nsec */
803 common_semi_set_ret(cs, 1000000000);
804 break;
805
806 case TARGET_SYS_SYNCCACHE:
807 /*
808 * Clean the D-cache and invalidate the I-cache for the specified
809 * virtual address range. This is a nop for us since we don't
810 * implement caches. This is only present on A64.
811 */
812 if (common_semi_has_synccache(env)) {
813 common_semi_set_ret(cs, 0);
814 break;
815 }
816 /* fall through */
817 default:
818 fprintf(stderr, "qemu: Unsupported SemiHosting SWI 0x%02x\n", nr);
819 cpu_dump_state(cs, stderr, 0);
820 abort();
821
822 do_fault:
823 common_semi_cb(cs, -1, EFAULT);
824 break;
825 }
826 }