--- /dev/null
+/***************************************************************************
+ * Copyright (C) 2009 by Marvell Technology Group Ltd. *
+ * Written by Nicolas Pitre <nico@marvell.com> *
+ * *
+ * 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 "armv4_5.h"
+#include "register.h"
+#include "arm_semihosting.h"
+#include <helper/binarybuffer.h>
+#include <helper/log.h>
+
+/* TODO: this needs to be per target */
+int semihosting_active;
+int semihosting_errno;
+
+static int do_semihosting(struct target *target)
+{
+ struct arm *armv4_5 = target_to_armv4_5(target);
+ uint32_t r0 = buf_get_u32(armv4_5->core_cache->reg_list[0].value, 0, 32);
+ uint32_t r1 = buf_get_u32(armv4_5->core_cache->reg_list[1].value, 0, 32);
+ uint32_t lr = buf_get_u32(ARMV4_5_CORE_REG_MODE(armv4_5->core_cache, ARMV4_5_MODE_SVC, 14).value, 0, 32);
+ uint32_t spsr = buf_get_u32(armv4_5->spsr->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.
+ */
+ 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];
+ int mode;
+ retval = target_read_memory(target, a, 1, l, fn);
+ if (retval != ERROR_OK)
+ return retval;
+ fn[l] = 0;
+ if (m & 0x2)
+ mode = O_RDWR;
+ else if (m & 0xc)
+ mode = O_WRONLY;
+ else
+ mode = O_RDONLY;
+ if (m >= 8)
+ mode |= O_CREAT|O_APPEND;
+ else if (m >= 4)
+ mode |= O_CREAT|O_TRUNC;
+ if (strcmp((char *)fn, ":tt") == 0) {
+ if ((mode & 3) == 0)
+ result = dup(0);
+ else
+ result = dup(1);
+ } else
+ result = open((char *)fn, mode);
+ semihosting_errno = errno;
+ } else {
+ result = -1;
+ 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);
+ 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;
+ 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);
+ 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;
+ semihosting_errno = ENOMEM;
+ } else {
+ result = read(fd, buf, l);
+ 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);
+ 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);
+ off_t cur = lseek(fd, 0, SEEK_CUR);
+ if (cur == (off_t)-1) {
+ semihosting_errno = errno;
+ result = -1;
+ break;
+ }
+ result = lseek(fd, 0, SEEK_END);
+ semihosting_errno = errno;
+ if (lseek(fd, cur, SEEK_SET) == (off_t)-1) {
+ semihosting_errno = errno;
+ result = -1;
+ }
+ }
+ 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);
+ semihosting_errno = errno;
+ } else {
+ result = -1;
+ 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);
+ semihosting_errno = errno;
+ } else {
+ result = -1;
+ semihosting_errno = EINVAL;
+ }
+ }
+ break;
+
+ case 0x11: /* SYS_TIME */
+ result = time(NULL);
+ break;
+
+ case 0x13: /* SYS_ERRNO */
+ result = 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", 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", r0);
+ result = -1;
+ semihosting_errno = ENOTSUP;
+ }
+
+ /* resume execution to the original mode */
+ buf_set_u32(armv4_5->core_cache->reg_list[0].value, 0, 32, result);
+ armv4_5->core_cache->reg_list[0].dirty = 1;
+ buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, lr);
+ armv4_5->core_cache->reg_list[15].dirty = 1;
+ buf_set_u32(armv4_5->core_cache->reg_list[ARMV4_5_CPSR].value, 0, 32, spsr);
+ armv4_5->core_cache->reg_list[ARMV4_5_CPSR].dirty = 1;
+ armv4_5->core_mode = spsr & 0x1f;
+ if (spsr & 0x20)
+ armv4_5->core_state = ARMV4_5_STATE_THUMB;
+ 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
+ * @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 *armv4_5 = target_to_armv4_5(target);
+ uint32_t lr, spsr;
+
+ if (!semihosting_active ||
+ armv4_5->core_mode != ARMV4_5_MODE_SVC ||
+ buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32) != 0x08)
+ return 0;
+
+ lr = buf_get_u32(ARMV4_5_CORE_REG_MODE(armv4_5->core_cache, ARMV4_5_MODE_SVC, 14).value, 0, 32);
+ spsr = buf_get_u32(armv4_5->spsr->value, 0, 32);
+
+ /* check instruction that triggered this trap */
+ if (spsr & (1 << 5)) {
+ /* was in Thumb 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);
+ if (insn != 0xDFAB)
+ 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);
+ if (insn != 0xEF123456)
+ return 0;
+ }
+
+ *retval = do_semihosting(target);
+ return 1;
+}
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