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semihosting: support fileio operation

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This patch adds support for bridging semihosting to GDB's File-I/O
remote protocol extension. For the most part operations match up 1:1,
however some require a working area to complete successfully, namely
operations that devolve to read, stat, and gettimeofday.

A new command was added to enable support for fileio named `arm
semihosting_fileio`, which ensures that the default behavior remains
intact for those that prefer it.

Finally, redundant logging was removed from the target_arch_state
function; this permits ARM targets to quiesce log output when polling
for a fileio reply. This prevents filling the logs with halt/resume
messages when using semihosting fileio.

Change-Id: Ifbb864fc2373336a501cc0332675b887b552e1ee
Signed-off-by: Steven Stallion <stallion@squareup.com>
Reviewed-on: http://openocd.zylin.com/3566
Tested-by: jenkins
Reviewed-by: Steven Stallion <sstallion@gmail.com>
Reviewed-by: Paul Fertser <fercerpav@gmail.com>
This commit is contained in:
Steven Stallion
2016-07-22 15:43:11 -05:00
committed by Paul Fertser
parent dc0a009ef4
commit c0e7ccbd87
12 changed files with 448 additions and 158 deletions
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512
src/target/arm_semihosting.c
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@@ -5,6 +5,9 @@
* Copyright (C) 2010 by Spencer Oliver *
* spen@spen-soft.co.uk *
* *
* Copyright (C) 2016 by Square, Inc. *
* Steven Stallion <stallion@squareup.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 *
@@ -43,6 +46,7 @@
#include "cortex_m.h"
#include "register.h"
#include "arm_opcodes.h"
#include "target_type.h"
#include "arm_semihosting.h"
#include <helper/binarybuffer.h>
#include <helper/log.h>
@@ -63,13 +67,59 @@ static const int open_modeflags[12] = {
O_RDWR | O_CREAT | O_APPEND | O_BINARY
};
static int post_result(struct target *target)
{
struct arm *arm = target_to_arm(target);
/* REVISIT this looks wrong ... ARM11 and Cortex-A8
* should work this way at least sometimes.
*/
if (is_arm7_9(target_to_arm7_9(target)) ||
is_armv7a(target_to_armv7a(target))) {
uint32_t spsr;
/* return value in R0 */
buf_set_u32(arm->core_cache->reg_list[0].value, 0, 32, arm->semihosting_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, arm->semihosting_result);
arm->core_cache->reg_list[0].dirty = 1;
}
return ERROR_OK;
}
static int do_semihosting(struct target *target)
{
struct arm *arm = target_to_arm(target);
struct gdb_fileio_info *fileio_info = target->fileio_info;
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;
int retval;
/*
* TODO: lots of security issues are not considered yet, such as:
@@ -77,10 +127,10 @@ static int do_semihosting(struct target *target)
* - 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.
* TODO: unsupported semihosting fileio operations could be
* implemented if we had a small working area at our disposal.
*/
switch (r0) {
switch ((arm->semihosting_op = r0)) {
case 0x01: /* SYS_OPEN */
retval = target_read_memory(target, r1, 4, 3, params);
if (retval != ERROR_OK)
@@ -89,27 +139,40 @@ static int do_semihosting(struct target *target)
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);
uint8_t fn[256];
retval = target_read_memory(target, a, 1, l, fn);
if (retval != ERROR_OK)
return retval;
fn[l] = 0;
if (arm->is_semihosting_fileio) {
if (strcmp((char *)fn, ":tt") == 0)
arm->semihosting_result = 0;
else {
arm->semihosting_hit_fileio = true;
fileio_info->identifier = "open";
fileio_info->param_1 = a;
fileio_info->param_2 = l;
fileio_info->param_3 = open_modeflags[m];
fileio_info->param_4 = 0644;
}
arm->semihosting_errno = errno;
} else {
result = -1;
arm->semihosting_errno = EINVAL;
if (l <= 255 && m <= 11) {
if (strcmp((char *)fn, ":tt") == 0) {
if (m < 4)
arm->semihosting_result = dup(STDIN_FILENO);
else
arm->semihosting_result = dup(STDOUT_FILENO);
} else {
/* cygwin requires the permission setting
* otherwise it will fail to reopen a previously
* written file */
arm->semihosting_result = open((char *)fn, open_modeflags[m], 0644);
}
arm->semihosting_errno = errno;
} else {
arm->semihosting_result = -1;
arm->semihosting_errno = EINVAL;
}
}
}
break;
@@ -120,33 +183,63 @@ static int do_semihosting(struct target *target)
return retval;
else {
int fd = target_buffer_get_u32(target, params+0);
result = close(fd);
arm->semihosting_errno = errno;
if (arm->is_semihosting_fileio) {
arm->semihosting_hit_fileio = true;
fileio_info->identifier = "close";
fileio_info->param_1 = fd;
} else {
arm->semihosting_result = close(fd);
arm->semihosting_errno = errno;
}
}
break;
case 0x03: /* SYS_WRITEC */
{
if (arm->is_semihosting_fileio) {
arm->semihosting_hit_fileio = true;
fileio_info->identifier = "write";
fileio_info->param_1 = 1;
fileio_info->param_2 = r1;
fileio_info->param_3 = 1;
} else {
unsigned char c;
retval = target_read_memory(target, r1, 1, 1, &c);
if (retval != ERROR_OK)
return retval;
putchar(c);
result = 0;
arm->semihosting_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;
if (arm->is_semihosting_fileio) {
size_t count = 0;
for (uint32_t a = r1;; a++) {
unsigned char c;
retval = target_read_memory(target, a, 1, 1, &c);
if (retval != ERROR_OK)
return retval;
if (c == '\0')
break;
count++;
}
arm->semihosting_hit_fileio = true;
fileio_info->identifier = "write";
fileio_info->param_1 = 1;
fileio_info->param_2 = r1;
fileio_info->param_3 = count;
} else {
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);
arm->semihosting_result = 0;
}
break;
case 0x05: /* SYS_WRITE */
@@ -157,21 +250,29 @@ static int do_semihosting(struct target *target)
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;
if (arm->is_semihosting_fileio) {
arm->semihosting_hit_fileio = true;
fileio_info->identifier = "write";
fileio_info->param_1 = fd;
fileio_info->param_2 = a;
fileio_info->param_3 = l;
} else {
retval = target_read_buffer(target, a, l, buf);
if (retval != ERROR_OK) {
uint8_t *buf = malloc(l);
if (!buf) {
arm->semihosting_result = -1;
arm->semihosting_errno = ENOMEM;
} else {
retval = target_read_buffer(target, a, l, buf);
if (retval != ERROR_OK) {
free(buf);
return retval;
}
arm->semihosting_result = write(fd, buf, l);
arm->semihosting_errno = errno;
if (arm->semihosting_result >= 0)
arm->semihosting_result = l - arm->semihosting_result;
free(buf);
return retval;
}
result = write(fd, buf, l);
arm->semihosting_errno = errno;
if (result >= 0)
result = l - result;
free(buf);
}
}
break;
@@ -184,42 +285,60 @@ static int do_semihosting(struct target *target)
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;
if (arm->is_semihosting_fileio) {
arm->semihosting_hit_fileio = true;
fileio_info->identifier = "read";
fileio_info->param_1 = fd;
fileio_info->param_2 = a;
fileio_info->param_3 = l;
} 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;
uint8_t *buf = malloc(l);
if (!buf) {
arm->semihosting_result = -1;
arm->semihosting_errno = ENOMEM;
} else {
arm->semihosting_result = read(fd, buf, l);
arm->semihosting_errno = errno;
if (arm->semihosting_result >= 0) {
retval = target_write_buffer(target, a, arm->semihosting_result, buf);
if (retval != ERROR_OK) {
free(buf);
return retval;
}
arm->semihosting_result = l - arm->semihosting_result;
}
result = l - result;
free(buf);
}
free(buf);
}
}
break;
case 0x07: /* SYS_READC */
result = getchar();
if (arm->is_semihosting_fileio) {
LOG_ERROR("SYS_READC not supported by semihosting fileio");
return ERROR_FAIL;
}
arm->semihosting_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);
arm->semihosting_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));
if (arm->is_semihosting_fileio) {
arm->semihosting_hit_fileio = true;
fileio_info->identifier = "isatty";
fileio_info->param_1 = r1;
} else {
retval = target_read_memory(target, r1, 4, 1, params);
if (retval != ERROR_OK)
return retval;
arm->semihosting_result = isatty(target_buffer_get_u32(target, params+0));
}
break;
case 0x0a: /* SYS_SEEK */
@@ -229,27 +348,39 @@ static int do_semihosting(struct target *target)
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;
if (arm->is_semihosting_fileio) {
arm->semihosting_hit_fileio = true;
fileio_info->identifier = "lseek";
fileio_info->param_1 = fd;
fileio_info->param_2 = pos;
fileio_info->param_3 = SEEK_SET;
} else {
arm->semihosting_result = lseek(fd, pos, SEEK_SET);
arm->semihosting_errno = errno;
if (arm->semihosting_result == pos)
arm->semihosting_result = 0;
}
}
break;
case 0x0c: /* SYS_FLEN */
if (arm->is_semihosting_fileio) {
LOG_ERROR("SYS_FLEN not supported by semihosting fileio");
return ERROR_FAIL;
}
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_result = fstat(fd, &buf);
if (arm->semihosting_result == -1) {
arm->semihosting_errno = errno;
result = -1;
arm->semihosting_result = -1;
break;
}
result = buf.st_size;
arm->semihosting_result = buf.st_size;
}
break;
@@ -260,17 +391,24 @@ static int do_semihosting(struct target *target)
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;
if (arm->is_semihosting_fileio) {
arm->semihosting_hit_fileio = true;
fileio_info->identifier = "unlink";
fileio_info->param_1 = a;
fileio_info->param_2 = l;
} else {
result = -1;
arm->semihosting_errno = EINVAL;
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;
arm->semihosting_result = remove((char *)fn);
arm->semihosting_errno = errno;
} else {
arm->semihosting_result = -1;
arm->semihosting_errno = EINVAL;
}
}
}
break;
@@ -284,31 +422,40 @@ static int do_semihosting(struct target *target)
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;
if (arm->is_semihosting_fileio) {
arm->semihosting_hit_fileio = true;
fileio_info->identifier = "rename";
fileio_info->param_1 = a1;
fileio_info->param_2 = l1;
fileio_info->param_3 = a2;
fileio_info->param_4 = l2;
} else {
result = -1;
arm->semihosting_errno = EINVAL;
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;
arm->semihosting_result = rename((char *)fn1, (char *)fn2);
arm->semihosting_errno = errno;
} else {
arm->semihosting_result = -1;
arm->semihosting_errno = EINVAL;
}
}
}
break;
case 0x11: /* SYS_TIME */
result = time(NULL);
arm->semihosting_result = time(NULL);
break;
case 0x13: /* SYS_ERRNO */
result = arm->semihosting_errno;
arm->semihosting_result = arm->semihosting_errno;
break;
case 0x15: /* SYS_GET_CMDLINE */
@@ -321,12 +468,12 @@ static int do_semihosting(struct target *target)
char *arg = "foobar";
uint32_t s = strlen(arg) + 1;
if (l < s)
result = -1;
arm->semihosting_result = -1;
else {
retval = target_write_buffer(target, a, s, (uint8_t *)arg);
if (retval != ERROR_OK)
return retval;
result = 0;
arm->semihosting_result = 0;
}
}
break;
@@ -342,7 +489,7 @@ static int do_semihosting(struct target *target)
retval = target_write_memory(target, a, 4, 4, params);
if (retval != ERROR_OK)
return retval;
result = 0;
arm->semihosting_result = 0;
}
break;
@@ -386,17 +533,24 @@ static int do_semihosting(struct target *target)
else {
uint32_t len = target_buffer_get_u32(target, params+4);
uint32_t c_ptr = target_buffer_get_u32(target, params);
uint8_t cmd[256];
if (len > 255) {
result = -1;
arm->semihosting_errno = EINVAL;
if (arm->is_semihosting_fileio) {
arm->semihosting_hit_fileio = true;
fileio_info->identifier = "system";
fileio_info->param_1 = c_ptr;
fileio_info->param_2 = len;
} else {
memset(cmd, 0x0, 256);
retval = target_read_memory(target, c_ptr, 1, len, cmd);
if (retval != ERROR_OK)
return retval;
else
result = system((const char *)cmd);
uint8_t cmd[256];
if (len > 255) {
arm->semihosting_result = -1;
arm->semihosting_errno = EINVAL;
} else {
memset(cmd, 0x0, 256);
retval = target_read_memory(target, c_ptr, 1, len, cmd);
if (retval != ERROR_OK)
return retval;
else
arm->semihosting_result = system((const char *)cmd);
}
}
}
break;
@@ -408,51 +562,84 @@ static int do_semihosting(struct target *target)
default:
fprintf(stderr, "semihosting: unsupported call %#x\n",
(unsigned) r0);
result = -1;
arm->semihosting_result = -1;
arm->semihosting_errno = ENOTSUP;
}
/* resume execution to the original mode */
return ERROR_OK;
}
/* REVISIT this looks wrong ... ARM11 and Cortex-A8
* should work this way at least sometimes.
static int get_gdb_fileio_info(struct target *target, struct gdb_fileio_info *fileio_info)
{
struct arm *arm = target_to_arm(target);
/* To avoid uneccessary duplication, semihosting prepares the
* fileio_info structure out-of-band when the target halts. See
* do_semihosting for more detail.
*/
if (is_arm7_9(target_to_arm7_9(target)) ||
is_armv7a(target_to_armv7a(target))) {
uint32_t spsr;
if (!arm->is_semihosting_fileio || !arm->semihosting_hit_fileio)
return ERROR_FAIL;
/* 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;
return ERROR_OK;
}
/* 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;
static int gdb_fileio_end(struct target *target, int result, int fileio_errno, bool ctrl_c)
{
struct arm *arm = target_to_arm(target);
struct gdb_fileio_info *fileio_info = target->fileio_info;
/* saved PSR --> current PSR */
spsr = buf_get_u32(arm->spsr->value, 0, 32);
/* clear pending status */
arm->semihosting_hit_fileio = false;
/* REVISIT should this be arm_set_cpsr(arm, spsr)
* instead of a partially unrolled version?
*/
arm->semihosting_result = result;
arm->semihosting_errno = fileio_errno;
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;
/* Some fileio results do not match up with what the semihosting
* operation expects; for these operations, we munge the results
* below:
*/
switch (arm->semihosting_op) {
case 0x05: /* SYS_WRITE */
if (result < 0)
arm->semihosting_result = fileio_info->param_3;
else
arm->semihosting_result = 0;
break;
} else {
/* resume execution, this will be pc+2 to skip over the
* bkpt instruction */
case 0x06: /* SYS_READ */
if (result == (int)fileio_info->param_3)
arm->semihosting_result = 0;
if (result <= 0)
arm->semihosting_result = fileio_info->param_3;
break;
/* 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;
case 0x0a: /* SYS_SEEK */
if (result > 0)
arm->semihosting_result = 0;
break;
}
return target_resume(target, 1, 0, 0, 0);
return post_result(target);
}
/**
* Initialize ARM semihosting support.
*
* @param target Pointer to the ARM target to initialize.
* @return An error status if there is a problem during initialization.
*/
int arm_semihosting_init(struct target *target)
{
target->fileio_info = malloc(sizeof(*target->fileio_info));
if (target->fileio_info == NULL) {
LOG_ERROR("out of memory");
return ERROR_FAIL;
}
target->type->get_gdb_fileio_info = get_gdb_fileio_info;
target->type->gdb_fileio_end = gdb_fileio_end;
return ERROR_OK;
}
/**
@@ -576,6 +763,35 @@ int arm_semihosting(struct target *target, int *retval)
return 0;
}
*retval = do_semihosting(target);
return 1;
/* Perform semihosting if we are not waiting on a fileio
* operation to complete.
*/
if (!arm->semihosting_hit_fileio) {
*retval = do_semihosting(target);
if (*retval != ERROR_OK) {
LOG_ERROR("Failed semihosting operation");
return 0;
}
}
/* Post result to target if we are not waiting on a fileio
* operation to complete:
*/
if (!arm->semihosting_hit_fileio) {
*retval = post_result(target);
if (*retval != ERROR_OK) {
LOG_ERROR("Failed to post semihosting result");
return 0;
}
*retval = target_resume(target, 1, 0, 0, 0);
if (*retval != ERROR_OK) {
LOG_ERROR("Failed to resume target");
return 0;
}
return 1;
}
return 0;
}