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- /***************************************************************************
- * Copyright (C) 2009 by Marvell Technology Group Ltd. *
- * Written by Nicolas Pitre <nico@marvell.com> *
- * *
- * Copyright (C) 2010 by Spencer Oliver *
- * spen@spen-soft.co.uk *
- * *
- * This program is free software; you can redistribute it and/or modify *
- * it under the terms of the GNU General Public License as published by *
- * the Free Software Foundation; either version 2 of the License, or *
- * (at your option) any later version. *
- * *
- * This program is distributed in the hope that it will be useful, *
- * but WITHOUT ANY WARRANTY; without even the implied warranty of *
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
- * GNU General Public License for more details. *
- * *
- * You should have received a copy of the GNU General Public License *
- * along with this program; if not, write to the *
- * Free Software Foundation, Inc., *
- * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
- ***************************************************************************/
-
- /**
- * @file
- * Hold ARM semihosting support.
- *
- * Semihosting enables code running on an ARM target to use the I/O
- * facilities on the host computer. The target application must be linked
- * against a library that forwards operation requests by using the SVC
- * instruction trapped at the Supervisor Call vector by the debugger.
- * Details can be found in chapter 8 of DUI0203I_rvct_developer_guide.pdf
- * from ARM Ltd.
- */
-
- #ifdef HAVE_CONFIG_H
- #include "config.h"
- #endif
-
- #include "arm.h"
- #include "armv4_5.h"
- #include "arm7_9_common.h"
- #include "armv7m.h"
- #include "cortex_m.h"
- #include "register.h"
- #include "arm_semihosting.h"
- #include <helper/binarybuffer.h>
- #include <helper/log.h>
- #include <sys/stat.h>
-
- static int open_modeflags[12] = {
- O_RDONLY,
- O_RDONLY | O_BINARY,
- O_RDWR,
- O_RDWR | O_BINARY,
- O_WRONLY | O_CREAT | O_TRUNC,
- O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
- O_RDWR | O_CREAT | O_TRUNC,
- O_RDWR | O_CREAT | O_TRUNC | O_BINARY,
- O_WRONLY | O_CREAT | O_APPEND,
- O_WRONLY | O_CREAT | O_APPEND | O_BINARY,
- O_RDWR | O_CREAT | O_APPEND,
- O_RDWR | O_CREAT | O_APPEND | O_BINARY
- };
-
- static int do_semihosting(struct target *target)
- {
- struct arm *arm = target_to_arm(target);
- uint32_t r0 = buf_get_u32(arm->core_cache->reg_list[0].value, 0, 32);
- uint32_t r1 = buf_get_u32(arm->core_cache->reg_list[1].value, 0, 32);
- uint8_t params[16];
- int retval, result;
-
- /*
- * TODO: lots of security issues are not considered yet, such as:
- * - no validation on target provided file descriptors
- * - no safety checks on opened/deleted/renamed file paths
- * Beware the target app you use this support with.
- *
- * TODO: explore mapping requests to GDB's "File-I/O Remote
- * Protocol Extension" ... when GDB is active.
- */
- switch (r0) {
- case 0x01: /* SYS_OPEN */
- retval = target_read_memory(target, r1, 4, 3, params);
- if (retval != ERROR_OK)
- return retval;
- else {
- uint32_t a = target_buffer_get_u32(target, params+0);
- uint32_t m = target_buffer_get_u32(target, params+4);
- uint32_t l = target_buffer_get_u32(target, params+8);
- if (l <= 255 && m <= 11) {
- uint8_t fn[256];
- retval = target_read_memory(target, a, 1, l, fn);
- if (retval != ERROR_OK)
- return retval;
- fn[l] = 0;
- if (strcmp((char *)fn, ":tt") == 0) {
- if (m < 4)
- result = dup(STDIN_FILENO);
- else
- result = dup(STDOUT_FILENO);
- } else {
- /* cygwin requires the permission setting
- * otherwise it will fail to reopen a previously
- * written file */
- result = open((char *)fn, open_modeflags[m], 0644);
- }
- arm->semihosting_errno = errno;
- } else {
- result = -1;
- arm->semihosting_errno = EINVAL;
- }
- }
- break;
-
- case 0x02: /* SYS_CLOSE */
- retval = target_read_memory(target, r1, 4, 1, params);
- if (retval != ERROR_OK)
- return retval;
- else {
- int fd = target_buffer_get_u32(target, params+0);
- result = close(fd);
- arm->semihosting_errno = errno;
- }
- break;
-
- case 0x03: /* SYS_WRITEC */
- {
- unsigned char c;
- retval = target_read_memory(target, r1, 1, 1, &c);
- if (retval != ERROR_OK)
- return retval;
- putchar(c);
- result = 0;
- }
- break;
-
- case 0x04: /* SYS_WRITE0 */
- do {
- unsigned char c;
- retval = target_read_memory(target, r1++, 1, 1, &c);
- if (retval != ERROR_OK)
- return retval;
- if (!c)
- break;
- putchar(c);
- } while (1);
- result = 0;
- break;
-
- case 0x05: /* SYS_WRITE */
- retval = target_read_memory(target, r1, 4, 3, params);
- if (retval != ERROR_OK)
- return retval;
- else {
- int fd = target_buffer_get_u32(target, params+0);
- uint32_t a = target_buffer_get_u32(target, params+4);
- size_t l = target_buffer_get_u32(target, params+8);
- uint8_t *buf = malloc(l);
- if (!buf) {
- result = -1;
- arm->semihosting_errno = ENOMEM;
- } else {
- retval = target_read_buffer(target, a, l, buf);
- if (retval != ERROR_OK) {
- free(buf);
- return retval;
- }
- result = write(fd, buf, l);
- arm->semihosting_errno = errno;
- if (result >= 0)
- result = l - result;
- free(buf);
- }
- }
- break;
-
- case 0x06: /* SYS_READ */
- retval = target_read_memory(target, r1, 4, 3, params);
- if (retval != ERROR_OK)
- return retval;
- else {
- int fd = target_buffer_get_u32(target, params+0);
- uint32_t a = target_buffer_get_u32(target, params+4);
- ssize_t l = target_buffer_get_u32(target, params+8);
- uint8_t *buf = malloc(l);
- if (!buf) {
- result = -1;
- arm->semihosting_errno = ENOMEM;
- } else {
- result = read(fd, buf, l);
- arm->semihosting_errno = errno;
- if (result >= 0) {
- retval = target_write_buffer(target, a, result, buf);
- if (retval != ERROR_OK) {
- free(buf);
- return retval;
- }
- result = l - result;
- }
- free(buf);
- }
- }
- break;
-
- case 0x07: /* SYS_READC */
- result = getchar();
- break;
-
- case 0x08: /* SYS_ISERROR */
- retval = target_read_memory(target, r1, 4, 1, params);
- if (retval != ERROR_OK)
- return retval;
- result = (target_buffer_get_u32(target, params+0) != 0);
- break;
-
- case 0x09: /* SYS_ISTTY */
- retval = target_read_memory(target, r1, 4, 1, params);
- if (retval != ERROR_OK)
- return retval;
- result = isatty(target_buffer_get_u32(target, params+0));
- break;
-
- case 0x0a: /* SYS_SEEK */
- retval = target_read_memory(target, r1, 4, 2, params);
- if (retval != ERROR_OK)
- return retval;
- else {
- int fd = target_buffer_get_u32(target, params+0);
- off_t pos = target_buffer_get_u32(target, params+4);
- result = lseek(fd, pos, SEEK_SET);
- arm->semihosting_errno = errno;
- if (result == pos)
- result = 0;
- }
- break;
-
- case 0x0c: /* SYS_FLEN */
- retval = target_read_memory(target, r1, 4, 1, params);
- if (retval != ERROR_OK)
- return retval;
- else {
- int fd = target_buffer_get_u32(target, params+0);
- struct stat buf;
- result = fstat(fd, &buf);
- if (result == -1) {
- arm->semihosting_errno = errno;
- result = -1;
- break;
- }
- result = buf.st_size;
- }
- break;
-
- case 0x0e: /* SYS_REMOVE */
- retval = target_read_memory(target, r1, 4, 2, params);
- if (retval != ERROR_OK)
- return retval;
- else {
- uint32_t a = target_buffer_get_u32(target, params+0);
- uint32_t l = target_buffer_get_u32(target, params+4);
- if (l <= 255) {
- uint8_t fn[256];
- retval = target_read_memory(target, a, 1, l, fn);
- if (retval != ERROR_OK)
- return retval;
- fn[l] = 0;
- result = remove((char *)fn);
- arm->semihosting_errno = errno;
- } else {
- result = -1;
- arm->semihosting_errno = EINVAL;
- }
- }
- break;
-
- case 0x0f: /* SYS_RENAME */
- retval = target_read_memory(target, r1, 4, 4, params);
- if (retval != ERROR_OK)
- return retval;
- else {
- uint32_t a1 = target_buffer_get_u32(target, params+0);
- uint32_t l1 = target_buffer_get_u32(target, params+4);
- uint32_t a2 = target_buffer_get_u32(target, params+8);
- uint32_t l2 = target_buffer_get_u32(target, params+12);
- if (l1 <= 255 && l2 <= 255) {
- uint8_t fn1[256], fn2[256];
- retval = target_read_memory(target, a1, 1, l1, fn1);
- if (retval != ERROR_OK)
- return retval;
- retval = target_read_memory(target, a2, 1, l2, fn2);
- if (retval != ERROR_OK)
- return retval;
- fn1[l1] = 0;
- fn2[l2] = 0;
- result = rename((char *)fn1, (char *)fn2);
- arm->semihosting_errno = errno;
- } else {
- result = -1;
- arm->semihosting_errno = EINVAL;
- }
- }
- break;
-
- case 0x11: /* SYS_TIME */
- result = time(NULL);
- break;
-
- case 0x13: /* SYS_ERRNO */
- result = arm->semihosting_errno;
- break;
-
- case 0x15: /* SYS_GET_CMDLINE */
- retval = target_read_memory(target, r1, 4, 2, params);
- if (retval != ERROR_OK)
- return retval;
- else {
- uint32_t a = target_buffer_get_u32(target, params+0);
- uint32_t l = target_buffer_get_u32(target, params+4);
- char *arg = "foobar";
- uint32_t s = strlen(arg) + 1;
- if (l < s)
- result = -1;
- else {
- retval = target_write_buffer(target, a, s, (void *)arg);
- if (retval != ERROR_OK)
- return retval;
- result = 0;
- }
- }
- break;
-
- case 0x16: /* SYS_HEAPINFO */
- retval = target_read_memory(target, r1, 4, 1, params);
- if (retval != ERROR_OK)
- return retval;
- else {
- uint32_t a = target_buffer_get_u32(target, params+0);
- /* tell the remote we have no idea */
- memset(params, 0, 4*4);
- retval = target_write_memory(target, a, 4, 4, params);
- if (retval != ERROR_OK)
- return retval;
- result = 0;
- }
- break;
-
- case 0x18: /* angel_SWIreason_ReportException */
- switch (r1) {
- case 0x20026: /* ADP_Stopped_ApplicationExit */
- fprintf(stderr, "semihosting: *** application exited ***\n");
- break;
- case 0x20000: /* ADP_Stopped_BranchThroughZero */
- case 0x20001: /* ADP_Stopped_UndefinedInstr */
- case 0x20002: /* ADP_Stopped_SoftwareInterrupt */
- case 0x20003: /* ADP_Stopped_PrefetchAbort */
- case 0x20004: /* ADP_Stopped_DataAbort */
- case 0x20005: /* ADP_Stopped_AddressException */
- case 0x20006: /* ADP_Stopped_IRQ */
- case 0x20007: /* ADP_Stopped_FIQ */
- case 0x20020: /* ADP_Stopped_BreakPoint */
- case 0x20021: /* ADP_Stopped_WatchPoint */
- case 0x20022: /* ADP_Stopped_StepComplete */
- case 0x20023: /* ADP_Stopped_RunTimeErrorUnknown */
- case 0x20024: /* ADP_Stopped_InternalError */
- case 0x20025: /* ADP_Stopped_UserInterruption */
- case 0x20027: /* ADP_Stopped_StackOverflow */
- case 0x20028: /* ADP_Stopped_DivisionByZero */
- case 0x20029: /* ADP_Stopped_OSSpecific */
- default:
- fprintf(stderr, "semihosting: exception %#x\n",
- (unsigned) r1);
- }
- return target_call_event_callbacks(target, TARGET_EVENT_HALTED);
-
- case 0x0d: /* SYS_TMPNAM */
- case 0x10: /* SYS_CLOCK */
- case 0x12: /* SYS_SYSTEM */
- case 0x17: /* angel_SWIreason_EnterSVC */
- case 0x30: /* SYS_ELAPSED */
- case 0x31: /* SYS_TICKFREQ */
- default:
- fprintf(stderr, "semihosting: unsupported call %#x\n",
- (unsigned) r0);
- result = -1;
- arm->semihosting_errno = ENOTSUP;
- }
-
- /* resume execution to the original mode */
-
- /* REVISIT this looks wrong ... ARM11 and Cortex-A8
- * should work this way at least sometimes.
- */
- if (is_arm7_9(target_to_arm7_9(target))) {
- uint32_t spsr;
-
- /* return value in R0 */
- buf_set_u32(arm->core_cache->reg_list[0].value, 0, 32, result);
- arm->core_cache->reg_list[0].dirty = 1;
-
- /* LR --> PC */
- buf_set_u32(arm->core_cache->reg_list[15].value, 0, 32,
- buf_get_u32(arm_reg_current(arm, 14)->value, 0, 32));
- arm->core_cache->reg_list[15].dirty = 1;
-
- /* saved PSR --> current PSR */
- spsr = buf_get_u32(arm->spsr->value, 0, 32);
-
- /* REVISIT should this be arm_set_cpsr(arm, spsr)
- * instead of a partially unrolled version?
- */
-
- buf_set_u32(arm->cpsr->value, 0, 32, spsr);
- arm->cpsr->dirty = 1;
- arm->core_mode = spsr & 0x1f;
- if (spsr & 0x20)
- arm->core_state = ARM_STATE_THUMB;
-
- } else {
- /* resume execution, this will be pc+2 to skip over the
- * bkpt instruction */
-
- /* return result in R0 */
- buf_set_u32(arm->core_cache->reg_list[0].value, 0, 32, result);
- arm->core_cache->reg_list[0].dirty = 1;
- }
-
- return target_resume(target, 1, 0, 0, 0);
- }
-
- /**
- * Checks for and processes an ARM semihosting request. This is meant
- * to be called when the target is stopped due to a debug mode entry.
- * If the value 0 is returned then there was nothing to process. A non-zero
- * return value signifies that a request was processed and the target resumed,
- * or an error was encountered, in which case the caller must return
- * immediately.
- *
- * @param target Pointer to the ARM target to process. This target must
- * not represent an ARMv6-M or ARMv7-M processor.
- * @param retval Pointer to a location where the return code will be stored
- * @return non-zero value if a request was processed or an error encountered
- */
- int arm_semihosting(struct target *target, int *retval)
- {
- struct arm *arm = target_to_arm(target);
- uint32_t pc, lr, spsr;
- struct reg *r;
-
- if (!arm->is_semihosting)
- return 0;
-
- if (is_arm7_9(target_to_arm7_9(target))) {
- if (arm->core_mode != ARM_MODE_SVC)
- return 0;
-
- /* Check for PC == 0x00000008 or 0xffff0008: Supervisor Call vector. */
- r = arm->pc;
- pc = buf_get_u32(r->value, 0, 32);
- if (pc != 0x00000008 && pc != 0xffff0008)
- return 0;
-
- r = arm_reg_current(arm, 14);
- lr = buf_get_u32(r->value, 0, 32);
-
- /* Core-specific code should make sure SPSR is retrieved
- * when the above checks pass...
- */
- if (!arm->spsr->valid) {
- LOG_ERROR("SPSR not valid!");
- *retval = ERROR_FAIL;
- return 1;
- }
-
- spsr = buf_get_u32(arm->spsr->value, 0, 32);
-
- /* check instruction that triggered this trap */
- if (spsr & (1 << 5)) {
- /* was in Thumb (or ThumbEE) mode */
- uint8_t insn_buf[2];
- uint16_t insn;
-
- *retval = target_read_memory(target, lr-2, 2, 1, insn_buf);
- if (*retval != ERROR_OK)
- return 1;
- insn = target_buffer_get_u16(target, insn_buf);
-
- /* SVC 0xab */
- if (insn != 0xDFAB)
- return 0;
- } else if (spsr & (1 << 24)) {
- /* was in Jazelle mode */
- return 0;
- } else {
- /* was in ARM mode */
- uint8_t insn_buf[4];
- uint32_t insn;
-
- *retval = target_read_memory(target, lr-4, 4, 1, insn_buf);
- if (*retval != ERROR_OK)
- return 1;
- insn = target_buffer_get_u32(target, insn_buf);
-
- /* SVC 0x123456 */
- if (insn != 0xEF123456)
- return 0;
- }
- } else if (is_armv7m(target_to_armv7m(target))) {
- uint16_t insn;
-
- if (target->debug_reason != DBG_REASON_BREAKPOINT)
- return 0;
-
- r = arm->pc;
- pc = buf_get_u32(r->value, 0, 32);
-
- pc &= ~1;
- *retval = target_read_u16(target, pc, &insn);
- if (*retval != ERROR_OK)
- return 1;
-
- /* bkpt 0xAB */
- if (insn != 0xBEAB)
- return 0;
- } else {
- LOG_ERROR("Unsupported semi-hosting Target");
- return 0;
- }
-
- *retval = do_semihosting(target);
- return 1;
- }
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