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riscv-openocd/src/target/semihosting_common.c

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/***************************************************************************
* Copyright (C) 2018 by Liviu Ionescu *
* <ilg@livius.net> *
* *
* Copyright (C) 2018 by Marvell Technology Group Ltd. *
* Written by Nicolas Pitre <nico@marvell.com> *
* *
* 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 *
* (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, see <http://www.gnu.org/licenses/>. *
***************************************************************************/
/**
* @file
* Common ARM semihosting support.
*
* Semihosting enables code running on a target to use some of the I/O
* facilities on the host computer. The target application must be linked
* against a library that forwards operation requests by using an
* instruction trapped by the debugger.
*
* Details can be found in
* "Semihosting for AArch32 and AArch64, Release 2.0"
* https://static.docs.arm.com/100863/0200/semihosting.pdf
* from ARM Ltd.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "target.h"
#include "target_type.h"
#include "semihosting_common.h"
#include <helper/binarybuffer.h>
#include <helper/log.h>
#include <sys/stat.h>
static const 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 semihosting_common_fileio_info(struct target *target,
struct gdb_fileio_info *fileio_info);
static int semihosting_common_fileio_end(struct target *target, int result,
int fileio_errno, bool ctrl_c);
static int semihosting_read_fields(struct target *target, size_t number,
uint8_t *fields);
static int semihosting_write_fields(struct target *target, size_t number,
uint8_t *fields);
static uint64_t semihosting_get_field(struct target *target, size_t index,
uint8_t *fields);
static void semihosting_set_field(struct target *target, uint64_t value,
size_t index,
uint8_t *fields);
/* Attempts to include gdb_server.h failed. */
extern int gdb_actual_connections;
/**
* Initialize common semihosting support.
*
* @param target Pointer to the target to initialize.
* @return An error status if there is a problem during initialization.
*/
int semihosting_common_init(struct target *target, void *setup,
void *post_result)
{
LOG_DEBUG(" ");
target->fileio_info = malloc(sizeof(*target->fileio_info));
if (target->fileio_info == NULL) {
LOG_ERROR("out of memory");
return ERROR_FAIL;
}
memset(target->fileio_info, 0, sizeof(*target->fileio_info));
struct semihosting *semihosting;
semihosting = malloc(sizeof(*target->semihosting));
if (semihosting == NULL) {
LOG_ERROR("out of memory");
return ERROR_FAIL;
}
semihosting->is_active = false;
semihosting->is_fileio = false;
semihosting->hit_fileio = false;
semihosting->is_resumable = false;
semihosting->has_resumable_exit = false;
semihosting->word_size_bytes = 0;
semihosting->op = -1;
semihosting->param = 0;
semihosting->result = -1;
semihosting->sys_errno = -1;
semihosting->cmdline = NULL;
/* If possible, update it in setup(). */
semihosting->setup_time = clock();
semihosting->setup = setup;
semihosting->post_result = post_result;
target->semihosting = semihosting;
target->type->get_gdb_fileio_info = semihosting_common_fileio_info;
target->type->gdb_fileio_end = semihosting_common_fileio_end;
return ERROR_OK;
}
/**
* Portable implementation of ARM semihosting calls.
* Performs the currently pending semihosting operation
* encoded in target->semihosting.
*/
int semihosting_common(struct target *target)
{
struct semihosting *semihosting = target->semihosting;
if (!semihosting) {
/* Silently ignore if the semhosting field was not set. */
return ERROR_OK;
}
struct gdb_fileio_info *fileio_info = target->fileio_info;
/*
* By default return an error.
* The actual result must be set by each function
*/
semihosting->result = -1;
/* Most operations are resumable, except the two exit calls. */
semihosting->is_resumable = true;
int retval;
/* Enough space to hold 4 long words. */
uint8_t fields[4*8];
LOG_DEBUG("op=0x%x, param=0x%" PRIx64, (int)semihosting->op,
semihosting->param);
switch (semihosting->op) {
case SEMIHOSTING_SYS_CLOCK: /* 0x10 */
/*
* Returns the number of centiseconds (hundredths of a second)
* since the execution started.
*
* Values returned can be of limited use for some benchmarking
* purposes because of communication overhead or other
* agent-specific factors. For example, with a debug hardware
* unit the request is passed back to the host for execution.
* This can lead to unpredictable delays in transmission and
* process scheduling.
*
* Use this function to calculate time intervals, by calculating
* differences between intervals with and without the code
* sequence to be timed.
*
* Entry
* The PARAMETER REGISTER must contain 0. There are no other
* parameters.
*
* Return
* On exit, the RETURN REGISTER contains:
* - The number of centiseconds since some arbitrary start
* point, if the call is successful.
* - –1 if the call is not successful. For example, because
* of a communications error.
*/
{
clock_t delta = clock() - semihosting->setup_time;
semihosting->result = delta / (CLOCKS_PER_SEC / 100);
}
break;
case SEMIHOSTING_SYS_CLOSE: /* 0x02 */
/*
* Closes a file on the host system. The handle must reference
* a file that was opened with SYS_OPEN.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* one-field argument block:
* - field 1 Contains a handle for an open file.
*
* Return
* On exit, the RETURN REGISTER contains:
* - 0 if the call is successful
* - –1 if the call is not successful.
*/
retval = semihosting_read_fields(target, 1, fields);
if (retval != ERROR_OK)
return retval;
else {
int fd = semihosting_get_field(target, 0, fields);
if (semihosting->is_fileio) {
if (fd == 0 || fd == 1 || fd == 2) {
semihosting->result = 0;
break;
}
semihosting->hit_fileio = true;
fileio_info->identifier = "close";
fileio_info->param_1 = fd;
} else {
semihosting->result = close(fd);
semihosting->sys_errno = errno;
LOG_DEBUG("close(%d)=%d", fd, (int)semihosting->result);
}
}
break;
case SEMIHOSTING_SYS_ERRNO: /* 0x13 */
/*
* Returns the value of the C library errno variable that is
* associated with the semihosting implementation. The errno
* variable can be set by a number of C library semihosted
* functions, including:
* - SYS_REMOVE
* - SYS_OPEN
* - SYS_CLOSE
* - SYS_READ
* - SYS_WRITE
* - SYS_SEEK.
*
* Whether errno is set or not, and to what value, is entirely
* host-specific, except where the ISO C standard defines the
* behavior.
*
* Entry
* There are no parameters. The PARAMETER REGISTER must be 0.
*
* Return
* On exit, the RETURN REGISTER contains the value of the C
* library errno variable.
*/
semihosting->result = semihosting->sys_errno;
break;
case SEMIHOSTING_SYS_EXIT: /* 0x18 */
/*
* Note: SYS_EXIT was called angel_SWIreason_ReportException in
* previous versions of the documentation.
*
* An application calls this operation to report an exception
* to the debugger directly. The most common use is to report
* that execution has completed, using ADP_Stopped_ApplicationExit.
*
* Note: This semihosting operation provides no means for 32-bit
* callers to indicate an application exit with a specified exit
* code. Semihosting callers may prefer to check for the presence
* of the SH_EXT_EXTENDED_REPORT_EXCEPTION extension and use
* the SYS_REPORT_EXCEPTION_EXTENDED operation instead, if it
* is available.
*
* Entry (32-bit)
* On entry, the PARAMETER register is set to a reason code
* describing the cause of the trap. Not all semihosting client
* implementations will necessarily trap every corresponding
* event. Important reason codes are:
*
* - ADP_Stopped_ApplicationExit 0x20026
* - ADP_Stopped_RunTimeErrorUnknown 0x20023
*
* Entry (64-bit)
* On entry, the PARAMETER REGISTER contains a pointer to a
* two-field argument block:
* - field 1 The exception type, which is one of the set of
* reason codes in the above tables.
* - field 2 A subcode, whose meaning depends on the reason
* code in field 1.
* In particular, if field 1 is ADP_Stopped_ApplicationExit
* then field 2 is an exit status code, as passed to the C
* standard library exit() function. A simulator receiving
* this request must notify a connected debugger, if present,
* and then exit with the specified status.
*
* Return
* No return is expected from these calls. However, it is
* possible for the debugger to request that the application
* continues by performing an RDI_Execute request or equivalent.
* In this case, execution continues with the registers as they
* were on entry to the operation, or as subsequently modified
* by the debugger.
*/
if (semihosting->word_size_bytes == 8) {
retval = semihosting_read_fields(target, 2, fields);
if (retval != ERROR_OK)
return retval;
else {
int type = semihosting_get_field(target, 0, fields);
int code = semihosting_get_field(target, 1, fields);
if (type == ADP_STOPPED_APPLICATION_EXIT) {
if (!gdb_actual_connections)
exit(code);
else {
fprintf(stderr,
"semihosting: *** application exited with %d ***\n",
code);
}
} else {
fprintf(stderr,
"semihosting: application exception %#x\n",
type);
}
}
} else {
if (semihosting->param == ADP_STOPPED_APPLICATION_EXIT) {
if (!gdb_actual_connections)
exit(0);
else {
fprintf(stderr,
"semihosting: *** application exited normally ***\n");
}
} else if (semihosting->param == ADP_STOPPED_RUN_TIME_ERROR) {
/* Chosen more or less arbitrarly to have a nicer message,
* otherwise all other return the same exit code 1. */
if (!gdb_actual_connections)
exit(1);
else {
fprintf(stderr,
"semihosting: *** application exited with error ***\n");
}
} else {
if (!gdb_actual_connections)
exit(1);
else {
fprintf(stderr,
"semihosting: application exception %#x\n",
(unsigned) semihosting->param);
}
}
}
if (!semihosting->has_resumable_exit) {
semihosting->is_resumable = false;
return target_call_event_callbacks(target, TARGET_EVENT_HALTED);
}
break;
case SEMIHOSTING_SYS_EXIT_EXTENDED: /* 0x20 */
/*
* This operation is only supported if the semihosting extension
* SH_EXT_EXIT_EXTENDED is implemented. SH_EXT_EXIT_EXTENDED is
* reported using feature byte 0, bit 0. If this extension is
* supported, then the implementation provides a means to
* report a normal exit with a nonzero exit status in both 32-bit
* and 64-bit semihosting APIs.
*
* The implementation must provide the semihosting call
* SYS_EXIT_EXTENDED for both A64 and A32/T32 semihosting APIs.
*
* SYS_EXIT_EXTENDED is used by an application to report an
* exception or exit to the debugger directly. The most common
* use is to report that execution has completed, using
* ADP_Stopped_ApplicationExit.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* two-field argument block:
* - field 1 The exception type, which should be one of the set
* of reason codes that are documented for the SYS_EXIT
* (0x18) call. For example, ADP_Stopped_ApplicationExit.
* - field 2 A subcode, whose meaning depends on the reason
* code in field 1. In particular, if field 1 is
* ADP_Stopped_ApplicationExit then field 2 is an exit status
* code, as passed to the C standard library exit() function.
* A simulator receiving this request must notify a connected
* debugger, if present, and then exit with the specified status.
*
* Return
* No return is expected from these calls.
*
* For the A64 API, this call is identical to the behavior of
* the mandatory SYS_EXIT (0x18) call. If this extension is
* supported, then both calls must be implemented.
*/
retval = semihosting_read_fields(target, 2, fields);
if (retval != ERROR_OK)
return retval;
else {
int type = semihosting_get_field(target, 0, fields);
int code = semihosting_get_field(target, 1, fields);
if (type == ADP_STOPPED_APPLICATION_EXIT) {
if (!gdb_actual_connections)
exit(code);
else {
fprintf(stderr,
"semihosting: *** application exited with %d ***\n",
code);
}
} else {
fprintf(stderr, "semihosting: exception %#x\n",
type);
}
}
if (!semihosting->has_resumable_exit) {
semihosting->is_resumable = false;
return target_call_event_callbacks(target, TARGET_EVENT_HALTED);
}
break;
case SEMIHOSTING_SYS_FLEN: /* 0x0C */
/*
* Returns the length of a specified file.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* one-field argument block:
* - field 1 A handle for a previously opened, seekable file
* object.
*
* Return
* On exit, the RETURN REGISTER contains:
* - The current length of the file object, if the call is
* successful.
* - –1 if an error occurs.
*/
if (semihosting->is_fileio) {
semihosting->result = -1;
semihosting->sys_errno = EINVAL;
}
retval = semihosting_read_fields(target, 1, fields);
if (retval != ERROR_OK)
return retval;
else {
int fd = semihosting_get_field(target, 0, fields);
struct stat buf;
semihosting->result = fstat(fd, &buf);
if (semihosting->result == -1) {
semihosting->sys_errno = errno;
LOG_DEBUG("fstat(%d)=%d", fd, (int)semihosting->result);
break;
}
LOG_DEBUG("fstat(%d)=%d", fd, (int)semihosting->result);
semihosting->result = buf.st_size;
}
break;
case SEMIHOSTING_SYS_GET_CMDLINE: /* 0x15 */
/*
* Returns the command line that is used for the call to the
* executable, that is, argc and argv.
*
* Entry
* On entry, the PARAMETER REGISTER points to a two-field data
* block to be used for returning the command string and its length:
* - field 1 A pointer to a buffer of at least the size that is
* specified in field 2.
* - field 2 The length of the buffer in bytes.
*
* Return
* On exit:
* If the call is successful, then the RETURN REGISTER contains 0,
* the PARAMETER REGISTER is unchanged, and the data block is
* updated as follows:
* - field 1 A pointer to a null-terminated string of the command
* line.
* - field 2 The length of the string in bytes.
* If the call is not successful, then the RETURN REGISTER
* contains -1.
*
* Note: The semihosting implementation might impose limits on
* the maximum length of the string that can be transferred.
* However, the implementation must be able to support a
* command-line length of at least 80 bytes.
*/
retval = semihosting_read_fields(target, 2, fields);
if (retval != ERROR_OK)
return retval;
else {
uint64_t addr = semihosting_get_field(target, 0, fields);
size_t size = semihosting_get_field(target, 1, fields);
char *arg = semihosting->cmdline != NULL ?
semihosting->cmdline : "";
uint32_t len = strlen(arg) + 1;
if (len > size)
semihosting->result = -1;
else {
semihosting_set_field(target, len, 1, fields);
retval = target_write_buffer(target, addr, len,
(uint8_t *)arg);
if (retval != ERROR_OK)
return retval;
semihosting->result = 0;
retval = semihosting_write_fields(target, 2, fields);
if (retval != ERROR_OK)
return retval;
}
LOG_DEBUG("SYS_GET_CMDLINE=[%s],%d", arg,
(int)semihosting->result);
}
break;
case SEMIHOSTING_SYS_HEAPINFO: /* 0x16 */
/*
* Returns the system stack and heap parameters.
*
* Entry
* On entry, the PARAMETER REGISTER contains the address of a
* pointer to a four-field data block. The contents of the data
* block are filled by the function. The following C-like
* pseudocode describes the layout of the block:
* struct block {
* void* heap_base;
* void* heap_limit;
* void* stack_base;
* void* stack_limit;
* };
*
* Return
* On exit, the PARAMETER REGISTER is unchanged and the data
* block has been updated.
*/
retval = semihosting_read_fields(target, 1, fields);
if (retval != ERROR_OK)
return retval;
else {
uint64_t addr = semihosting_get_field(target, 0, fields);
/* tell the remote we have no idea */
memset(fields, 0, 4 * semihosting->word_size_bytes);
retval = target_write_memory(target, addr, 4,
semihosting->word_size_bytes,
fields);
if (retval != ERROR_OK)
return retval;
semihosting->result = 0;
}
break;
case SEMIHOSTING_SYS_ISERROR: /* 0x08 */
/*
* Determines whether the return code from another semihosting
* call is an error status or not.
*
* This call is passed a parameter block containing the error
* code to examine.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* one-field data block:
* - field 1 The required status word to check.
*
* Return
* On exit, the RETURN REGISTER contains:
* - 0 if the status field is not an error indication
* - A nonzero value if the status field is an error indication.
*/
retval = semihosting_read_fields(target, 1, fields);
if (retval != ERROR_OK)
return retval;
uint64_t code = semihosting_get_field(target, 0, fields);
semihosting->result = (code != 0);
break;
case SEMIHOSTING_SYS_ISTTY: /* 0x09 */
/*
* Checks whether a file is connected to an interactive device.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* one-field argument block:
* field 1 A handle for a previously opened file object.
*
* Return
* On exit, the RETURN REGISTER contains:
* - 1 if the handle identifies an interactive device.
* - 0 if the handle identifies a file.
* - A value other than 1 or 0 if an error occurs.
*/
if (semihosting->is_fileio) {
semihosting->hit_fileio = true;
fileio_info->identifier = "isatty";
fileio_info->param_1 = semihosting->param;
} else {
retval = semihosting_read_fields(target, 1, fields);
if (retval != ERROR_OK)
return retval;
int fd = semihosting_get_field(target, 0, fields);
semihosting->result = isatty(fd);
LOG_DEBUG("isatty(%d)=%d", fd, (int)semihosting->result);
}
break;
case SEMIHOSTING_SYS_OPEN: /* 0x01 */
/*
* Opens a file on the host system.
*
* The file path is specified either as relative to the current
* directory of the host process, or absolute, using the path
* conventions of the host operating system.
*
* Semihosting implementations must support opening the special
* path name :semihosting-features as part of the semihosting
* extensions reporting mechanism.
*
* ARM targets interpret the special path name :tt as meaning
* the console input stream, for an open-read or the console
* output stream, for an open-write. Opening these streams is
* performed as part of the standard startup code for those
* applications that reference the C stdio streams. The
* semihosting extension SH_EXT_STDOUT_STDERR allows the
* semihosting caller to open separate output streams
* corresponding to stdout and stderr. This extension is
* reported using feature byte 0, bit 1. Use SYS_OPEN with
* the special path name :semihosting-features to access the
* feature bits.
*
* If this extension is supported, the implementation must
* support the following additional semantics to SYS_OPEN:
* - If the special path name :tt is opened with an fopen
* mode requesting write access (w, wb, w+, or w+b), then
* this is a request to open stdout.
* - If the special path name :tt is opened with a mode
* requesting append access (a, ab, a+, or a+b), then this is
* a request to open stderr.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* three-field argument block:
* - field 1 A pointer to a null-terminated string containing
* a file or device name.
* - field 2 An integer that specifies the file opening mode.
* - field 3 An integer that gives the length of the string
* pointed to by field 1.
*
* The length does not include the terminating null character
* that must be present.
*
* Return
* On exit, the RETURN REGISTER contains:
* - A nonzero handle if the call is successful.
* - –1 if the call is not successful.
*/
retval = semihosting_read_fields(target, 3, fields);
if (retval != ERROR_OK)
return retval;
else {
uint64_t addr = semihosting_get_field(target, 0, fields);
uint32_t mode = semihosting_get_field(target, 1, fields);
size_t len = semihosting_get_field(target, 2, fields);
if (mode > 11) {
semihosting->result = -1;
semihosting->sys_errno = EINVAL;
break;
}
uint8_t *fn = malloc(len+1);
if (!fn) {
semihosting->result = -1;
semihosting->sys_errno = ENOMEM;
} else {
retval = target_read_memory(target, addr, 1, len, fn);
if (retval != ERROR_OK) {
free(fn);
return retval;
}
fn[len] = 0;
/* TODO: implement the :semihosting-features special file.
* */
if (semihosting->is_fileio) {
if (strcmp((char *)fn, ":semihosting-features") == 0) {
semihosting->result = -1;
semihosting->sys_errno = EINVAL;
} else if (strcmp((char *)fn, ":tt") == 0) {
if (mode == 0)
semihosting->result = 0;
else if (mode == 4)
semihosting->result = 1;
else if (mode == 8)
semihosting->result = 2;
else
semihosting->result = -1;
} else {
semihosting->hit_fileio = true;
fileio_info->identifier = "open";
fileio_info->param_1 = addr;
fileio_info->param_2 = len;
fileio_info->param_3 = open_modeflags[mode];
fileio_info->param_4 = 0644;
}
} else {
if (strcmp((char *)fn, ":tt") == 0) {
/* Mode is:
* - 0-3 ("r") for stdin,
* - 4-7 ("w") for stdout,
* - 8-11 ("a") for stderr */
if (mode < 4) {
semihosting->result = dup(
STDIN_FILENO);
semihosting->sys_errno = errno;
LOG_DEBUG("dup(STDIN)=%d",
(int)semihosting->result);
} else if (mode < 8) {
semihosting->result = dup(
STDOUT_FILENO);
semihosting->sys_errno = errno;
LOG_DEBUG("dup(STDOUT)=%d",
(int)semihosting->result);
} else {
semihosting->result = dup(
STDERR_FILENO);
semihosting->sys_errno = errno;
LOG_DEBUG("dup(STDERR)=%d",
(int)semihosting->result);
}
} else {
/* cygwin requires the permission setting
* otherwise it will fail to reopen a previously
* written file */
semihosting->result = open((char *)fn,
open_modeflags[mode],
0644);
semihosting->sys_errno = errno;
LOG_DEBUG("open('%s')=%d", fn,
(int)semihosting->result);
}
}
free(fn);
}
}
break;
case SEMIHOSTING_SYS_READ: /* 0x06 */
/*
* Reads the contents of a file into a buffer. The file position
* is specified either:
* - Explicitly by a SYS_SEEK.
* - Implicitly one byte beyond the previous SYS_READ or
* SYS_WRITE request.
*
* The file position is at the start of the file when it is
* opened, and is lost when the file is closed. Perform the
* file operation as a single action whenever possible. For
* example, do not split a read of 16KB into four 4KB chunks
* unless there is no alternative.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* three-field data block:
* - field 1 Contains a handle for a file previously opened
* with SYS_OPEN.
* - field 2 Points to a buffer.
* - field 3 Contains the number of bytes to read to the buffer
* from the file.
*
* Return
* On exit, the RETURN REGISTER contains the number of bytes not
* filled in the buffer (buffer_length - bytes_read) as follows:
* - If the RETURN REGISTER is 0, the entire buffer was
* successfully filled.
* - If the RETURN REGISTER is the same as field 3, no bytes
* were read (EOF can be assumed).
* - If the RETURN REGISTER contains a value smaller than
* field 3, the read succeeded but the buffer was only partly
* filled. For interactive devices, this is the most common
* return value.
*/
retval = semihosting_read_fields(target, 3, fields);
if (retval != ERROR_OK)
return retval;
else {
int fd = semihosting_get_field(target, 0, fields);
uint64_t addr = semihosting_get_field(target, 1, fields);
size_t len = semihosting_get_field(target, 2, fields);
if (semihosting->is_fileio) {
semihosting->hit_fileio = true;
fileio_info->identifier = "read";
fileio_info->param_1 = fd;
fileio_info->param_2 = addr;
fileio_info->param_3 = len;
} else {
uint8_t *buf = malloc(len);
if (!buf) {
semihosting->result = -1;
semihosting->sys_errno = ENOMEM;
} else {
semihosting->result = read(fd, buf, len);
semihosting->sys_errno = errno;
LOG_DEBUG("read(%d, 0x%" PRIx64 ", %zu)=%d",
fd,
addr,
len,
(int)semihosting->result);
if (semihosting->result >= 0) {
retval = target_write_buffer(target, addr,
semihosting->result,
buf);
if (retval != ERROR_OK) {
free(buf);
return retval;
}
/* the number of bytes NOT filled in */
semihosting->result = len -
semihosting->result;
}
free(buf);
}
}
}
break;
case SEMIHOSTING_SYS_READC: /* 0x07 */
/*
* Reads a byte from the console.
*
* Entry
* The PARAMETER REGISTER must contain 0. There are no other
* parameters or values possible.
*
* Return
* On exit, the RETURN REGISTER contains the byte read from
* the console.
*/
if (semihosting->is_fileio) {
LOG_ERROR("SYS_READC not supported by semihosting fileio");
return ERROR_FAIL;
}
semihosting->result = getchar();
LOG_DEBUG("getchar()=%d", (int)semihosting->result);
break;
case SEMIHOSTING_SYS_REMOVE: /* 0x0E */
/*
* Deletes a specified file on the host filing system.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* two-field argument block:
* - field 1 Points to a null-terminated string that gives the
* path name of the file to be deleted.
* - field 2 The length of the string.
*
* Return
* On exit, the RETURN REGISTER contains:
* - 0 if the delete is successful
* - A nonzero, host-specific error code if the delete fails.
*/
retval = semihosting_read_fields(target, 2, fields);
if (retval != ERROR_OK)
return retval;
else {
uint64_t addr = semihosting_get_field(target, 0, fields);
size_t len = semihosting_get_field(target, 1, fields);
if (semihosting->is_fileio) {
semihosting->hit_fileio = true;
fileio_info->identifier = "unlink";
fileio_info->param_1 = addr;
fileio_info->param_2 = len;
} else {
uint8_t *fn = malloc(len+1);
if (!fn) {
semihosting->result = -1;
semihosting->sys_errno = ENOMEM;
} else {
retval =
target_read_memory(target, addr, 1, len,
fn);
if (retval != ERROR_OK) {
free(fn);
return retval;
}
fn[len] = 0;
semihosting->result = remove((char *)fn);
semihosting->sys_errno = errno;
LOG_DEBUG("remove('%s')=%d", fn,
(int)semihosting->result);
free(fn);
}
}
}
break;
case SEMIHOSTING_SYS_RENAME: /* 0x0F */
/*
* Renames a specified file.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* four-field data block:
* - field 1 A pointer to the name of the old file.
* - field 2 The length of the old filename.
* - field 3 A pointer to the new filename.
* - field 4 The length of the new filename. Both strings are
* null-terminated.
*
* Return
* On exit, the RETURN REGISTER contains:
* - 0 if the rename is successful.
* - A nonzero, host-specific error code if the rename fails.
*/
retval = semihosting_read_fields(target, 4, fields);
if (retval != ERROR_OK)
return retval;
else {
uint64_t addr1 = semihosting_get_field(target, 0, fields);
size_t len1 = semihosting_get_field(target, 1, fields);
uint64_t addr2 = semihosting_get_field(target, 2, fields);
size_t len2 = semihosting_get_field(target, 3, fields);
if (semihosting->is_fileio) {
semihosting->hit_fileio = true;
fileio_info->identifier = "rename";
fileio_info->param_1 = addr1;
fileio_info->param_2 = len1;
fileio_info->param_3 = addr2;
fileio_info->param_4 = len2;
} else {
uint8_t *fn1 = malloc(len1+1);
uint8_t *fn2 = malloc(len2+1);
if (!fn1 || !fn2) {
free(fn1);
free(fn2);
semihosting->result = -1;
semihosting->sys_errno = ENOMEM;
} else {
retval = target_read_memory(target, addr1, 1, len1,
fn1);
if (retval != ERROR_OK) {
free(fn1);
free(fn2);
return retval;
}
retval = target_read_memory(target, addr2, 1, len2,
fn2);
if (retval != ERROR_OK) {
free(fn1);
free(fn2);
return retval;
}
fn1[len1] = 0;
fn2[len2] = 0;
semihosting->result = rename((char *)fn1,
(char *)fn2);
semihosting->sys_errno = errno;
LOG_DEBUG("rename('%s', '%s')=%d", fn1, fn2,
(int)semihosting->result);
free(fn1);
free(fn2);
}
}
}
break;
case SEMIHOSTING_SYS_SEEK: /* 0x0A */
/*
* Seeks to a specified position in a file using an offset
* specified from the start of the file. The file is assumed
* to be a byte array and the offset is given in bytes.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* two-field data block:
* - field 1 A handle for a seekable file object.
* - field 2 The absolute byte position to seek to.
*
* Return
* On exit, the RETURN REGISTER contains:
* - 0 if the request is successful.
* - A negative value if the request is not successful.
* Use SYS_ERRNO to read the value of the host errno variable
* describing the error.
*
* Note: The effect of seeking outside the current extent of
* the file object is undefined.
*/
retval = semihosting_read_fields(target, 2, fields);
if (retval != ERROR_OK)
return retval;
else {
int fd = semihosting_get_field(target, 0, fields);
off_t pos = semihosting_get_field(target, 1, fields);
if (semihosting->is_fileio) {
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 {
semihosting->result = lseek(fd, pos, SEEK_SET);
semihosting->sys_errno = errno;
LOG_DEBUG("lseek(%d, %d)=%d", fd, (int)pos,
(int)semihosting->result);
if (semihosting->result == pos)
semihosting->result = 0;
}
}
break;
case SEMIHOSTING_SYS_SYSTEM: /* 0x12 */
/*
* Passes a command to the host command-line interpreter.
* This enables you to execute a system command such as dir,
* ls, or pwd. The terminal I/O is on the host, and is not
* visible to the target.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* two-field argument block:
* - field 1 Points to a string to be passed to the host
* command-line interpreter.
* - field 2 The length of the string.
*
* Return
* On exit, the RETURN REGISTER contains the return status.
*/
/* Provide SYS_SYSTEM functionality. Uses the
* libc system command, there may be a reason *NOT*
* to use this, but as I can't think of one, I
* implemented it this way.
*/
retval = semihosting_read_fields(target, 2, fields);
if (retval != ERROR_OK)
return retval;
else {
uint64_t addr = semihosting_get_field(target, 0, fields);
size_t len = semihosting_get_field(target, 1, fields);
if (semihosting->is_fileio) {
semihosting->hit_fileio = true;
fileio_info->identifier = "system";
fileio_info->param_1 = addr;
fileio_info->param_2 = len;
} else {
uint8_t *cmd = malloc(len+1);
if (!cmd) {
semihosting->result = -1;
semihosting->sys_errno = ENOMEM;
} else {
retval = target_read_memory(target,
addr,
1,
len,
cmd);
if (retval != ERROR_OK) {
free(cmd);
return retval;
} else {
cmd[len] = 0;
semihosting->result = system(
(const char *)cmd);
LOG_DEBUG("system('%s')=%d",
cmd,
(int)semihosting->result);
}
free(cmd);
}
}
}
break;
case SEMIHOSTING_SYS_TIME: /* 0x11 */
/*
* Returns the number of seconds since 00:00 January 1, 1970.
* This value is real-world time, regardless of any debug agent
* configuration.
*
* Entry
* There are no parameters.
*
* Return
* On exit, the RETURN REGISTER contains the number of seconds.
*/
semihosting->result = time(NULL);
break;
case SEMIHOSTING_SYS_WRITE: /* 0x05 */
/*
* Writes the contents of a buffer to a specified file at the
* current file position. The file position is specified either:
* - Explicitly, by a SYS_SEEK.
* - Implicitly as one byte beyond the previous SYS_READ or
* SYS_WRITE request.
*
* The file position is at the start of the file when the file
* is opened, and is lost when the file is closed.
*
* Perform the file operation as a single action whenever
* possible. For example, do not split a write of 16KB into
* four 4KB chunks unless there is no alternative.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* three-field data block:
* - field 1 Contains a handle for a file previously opened
* with SYS_OPEN.
* - field 2 Points to the memory containing the data to be written.
* - field 3 Contains the number of bytes to be written from
* the buffer to the file.
*
* Return
* On exit, the RETURN REGISTER contains:
* - 0 if the call is successful.
* - The number of bytes that are not written, if there is an error.
*/
retval = semihosting_read_fields(target, 3, fields);
if (retval != ERROR_OK)
return retval;
else {
int fd = semihosting_get_field(target, 0, fields);
uint64_t addr = semihosting_get_field(target, 1, fields);
size_t len = semihosting_get_field(target, 2, fields);
if (semihosting->is_fileio) {
semihosting->hit_fileio = true;
fileio_info->identifier = "write";
fileio_info->param_1 = fd;
fileio_info->param_2 = addr;
fileio_info->param_3 = len;
} else {
uint8_t *buf = malloc(len);
if (!buf) {
semihosting->result = -1;
semihosting->sys_errno = ENOMEM;
} else {
retval = target_read_buffer(target, addr, len, buf);
if (retval != ERROR_OK) {
free(buf);
return retval;
}
semihosting->result = write(fd, buf, len);
semihosting->sys_errno = errno;
LOG_DEBUG("write(%d, 0x%" PRIx64 ", %zu)=%d",
fd,
addr,
len,
(int)semihosting->result);
if (semihosting->result >= 0) {
/* The number of bytes that are NOT written.
* */
semihosting->result = len -
semihosting->result;
}
free(buf);
}
}
}
break;
case SEMIHOSTING_SYS_WRITEC: /* 0x03 */
/*
* Writes a character byte, pointed to by the PARAMETER REGISTER,
* to the debug channel. When executed under a semihosting
* debugger, the character appears on the host debugger console.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to the
* character.
*
* Return
* None. The RETURN REGISTER is corrupted.
*/
if (semihosting->is_fileio) {
semihosting->hit_fileio = true;
fileio_info->identifier = "write";
fileio_info->param_1 = 1;
fileio_info->param_2 = semihosting->param;
fileio_info->param_3 = 1;
} else {
uint64_t addr = semihosting->param;
unsigned char c;
retval = target_read_memory(target, addr, 1, 1, &c);
if (retval != ERROR_OK)
return retval;
putchar(c);
semihosting->result = 0;
}
break;
case SEMIHOSTING_SYS_WRITE0: /* 0x04 */
/*
* Writes a null-terminated string to the debug channel.
* When executed under a semihosting debugger, the characters
* appear on the host debugger console.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to the
* first byte of the string.
*
* Return
* None. The RETURN REGISTER is corrupted.
*/
if (semihosting->is_fileio) {
size_t count = 0;
uint64_t addr = semihosting->param;
for (;; addr++) {
unsigned char c;
retval = target_read_memory(target, addr, 1, 1, &c);
if (retval != ERROR_OK)
return retval;
if (c == '\0')
break;
count++;
}
semihosting->hit_fileio = true;
fileio_info->identifier = "write";
fileio_info->param_1 = 1;
fileio_info->param_2 = semihosting->param;
fileio_info->param_3 = count;
} else {
uint64_t addr = semihosting->param;
do {
unsigned char c;
retval = target_read_memory(target, addr++, 1, 1, &c);
if (retval != ERROR_OK)
return retval;
if (!c)
break;
putchar(c);
} while (1);
semihosting->result = 0;
}
break;
case SEMIHOSTING_SYS_ELAPSED: /* 0x30 */
/*
* Returns the number of elapsed target ticks since execution
* started.
* Use SYS_TICKFREQ to determine the tick frequency.
*
* Entry (32-bit)
* On entry, the PARAMETER REGISTER points to a two-field data
* block to be used for returning the number of elapsed ticks:
* - field 1 The least significant field and is at the low address.
* - field 2 The most significant field and is at the high address.
*
* Entry (64-bit)
* On entry the PARAMETER REGISTER points to a one-field data
* block to be used for returning the number of elapsed ticks:
* - field 1 The number of elapsed ticks as a 64-bit value.
*
* Return
* On exit:
* - On success, the RETURN REGISTER contains 0, the PARAMETER
* REGISTER is unchanged, and the data block pointed to by the
* PARAMETER REGISTER is filled in with the number of elapsed
* ticks.
* - On failure, the RETURN REGISTER contains -1, and the
* PARAMETER REGISTER contains -1.
*
* Note: Some semihosting implementations might not support this
* semihosting operation, and they always return -1 in the
* RETURN REGISTER.
*/
case SEMIHOSTING_SYS_TICKFREQ: /* 0x31 */
/*
* Returns the tick frequency.
*
* Entry
* The PARAMETER REGISTER must contain 0 on entry to this routine.
*
* Return
* On exit, the RETURN REGISTER contains either:
* - The number of ticks per second.
* - –1 if the target does not know the value of one tick.
*
* Note: Some semihosting implementations might not support
* this semihosting operation, and they always return -1 in the
* RETURN REGISTER.
*/
case SEMIHOSTING_SYS_TMPNAM: /* 0x0D */
/*
* Returns a temporary name for a file identified by a system
* file identifier.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* three-word argument block:
* - field 1 A pointer to a buffer.
* - field 2 A target identifier for this filename. Its value
* must be an integer in the range 0-255.
* - field 3 Contains the length of the buffer. The length must
* be at least the value of L_tmpnam on the host system.
*
* Return
* On exit, the RETURN REGISTER contains:
* - 0 if the call is successful.
* - –1 if an error occurs.
*
* The buffer pointed to by the PARAMETER REGISTER contains
* the filename, prefixed with a suitable directory name.
* If you use the same target identifier again, the same
* filename is returned.
*
* Note: The returned string must be null-terminated.
*/
default:
fprintf(stderr, "semihosting: unsupported call %#x\n",
(unsigned) semihosting->op);
semihosting->result = -1;
semihosting->sys_errno = ENOTSUP;
}
if (!semihosting->hit_fileio) {
retval = semihosting->post_result(target);
if (retval != ERROR_OK) {
LOG_ERROR("Failed to post semihosting result");
return retval;
}
}
return ERROR_OK;
}
/* -------------------------------------------------------------------------
* Local functions. */
static int semihosting_common_fileio_info(struct target *target,
struct gdb_fileio_info *fileio_info)
{
struct semihosting *semihosting = target->semihosting;
if (!semihosting)
return ERROR_FAIL;
/*
* To avoid unnecessary duplication, semihosting prepares the
* fileio_info structure out-of-band when the target halts. See
* do_semihosting for more detail.
*/
if (!semihosting->is_fileio || !semihosting->hit_fileio)
return ERROR_FAIL;
return ERROR_OK;
}
static int semihosting_common_fileio_end(struct target *target, int result,
int fileio_errno, bool ctrl_c)
{
struct gdb_fileio_info *fileio_info = target->fileio_info;
struct semihosting *semihosting = target->semihosting;
if (!semihosting)
return ERROR_FAIL;
/* clear pending status */
semihosting->hit_fileio = false;
semihosting->result = result;
semihosting->sys_errno = fileio_errno;
/*
* Some fileio results do not match up with what the semihosting
* operation expects; for these operations, we munge the results
* below:
*/
switch (semihosting->op) {
case SEMIHOSTING_SYS_WRITE: /* 0x05 */
if (result < 0)
semihosting->result = fileio_info->param_3;
else
semihosting->result = 0;
break;
case SEMIHOSTING_SYS_READ: /* 0x06 */
if (result == (int)fileio_info->param_3)
semihosting->result = 0;
if (result <= 0)
semihosting->result = fileio_info->param_3;
break;
case SEMIHOSTING_SYS_SEEK: /* 0x0a */
if (result > 0)
semihosting->result = 0;
break;
}
return semihosting->post_result(target);
}
/**
* Read all fields of a command from target to buffer.
*/
static int semihosting_read_fields(struct target *target, size_t number,
uint8_t *fields)
{
struct semihosting *semihosting = target->semihosting;
/* Use 4-byte multiples to trigger fast memory access. */
return target_read_memory(target, semihosting->param, 4,
number * (semihosting->word_size_bytes / 4), fields);
}
/**
* Write all fields of a command from buffer to target.
*/
static int semihosting_write_fields(struct target *target, size_t number,
uint8_t *fields)
{
struct semihosting *semihosting = target->semihosting;
/* Use 4-byte multiples to trigger fast memory access. */
return target_write_memory(target, semihosting->param, 4,
number * (semihosting->word_size_bytes / 4), fields);
}
/**
* Extract a field from the buffer, considering register size and endianness.
*/
static uint64_t semihosting_get_field(struct target *target, size_t index,
uint8_t *fields)
{
struct semihosting *semihosting = target->semihosting;
if (semihosting->word_size_bytes == 8)
return target_buffer_get_u64(target, fields + (index * 8));
else
return target_buffer_get_u32(target, fields + (index * 4));
}
/**
* Store a field in the buffer, considering register size and endianness.
*/
static void semihosting_set_field(struct target *target, uint64_t value,
size_t index,
uint8_t *fields)
{
struct semihosting *semihosting = target->semihosting;
if (semihosting->word_size_bytes == 8)
target_buffer_set_u64(target, fields + (index * 8), value);
else
target_buffer_set_u32(target, fields + (index * 4), value);
}
/* -------------------------------------------------------------------------
* Common semihosting commands handlers. */
static __COMMAND_HANDLER(handle_common_semihosting_command)
{
struct target *target = get_current_target(CMD_CTX);
if (target == NULL) {
LOG_ERROR("No target selected");
return ERROR_FAIL;
}
struct semihosting *semihosting = target->semihosting;
if (!semihosting) {
command_print(CMD, "semihosting not supported for current target");
return ERROR_FAIL;
}
if (CMD_ARGC > 0) {
int is_active;
COMMAND_PARSE_ENABLE(CMD_ARGV[0], is_active);
if (!target_was_examined(target)) {
LOG_ERROR("Target not examined yet");
return ERROR_FAIL;
}
if (semihosting && semihosting->setup(target, is_active) != ERROR_OK) {
LOG_ERROR("Failed to Configure semihosting");
return ERROR_FAIL;
}
/* FIXME never let that "catch" be dropped! (???) */
semihosting->is_active = is_active;
}
command_print(CMD, "semihosting is %s",
semihosting->is_active
? "enabled" : "disabled");
return ERROR_OK;
}
static __COMMAND_HANDLER(handle_common_semihosting_fileio_command)
{
struct target *target = get_current_target(CMD_CTX);
if (target == NULL) {
LOG_ERROR("No target selected");
return ERROR_FAIL;
}
struct semihosting *semihosting = target->semihosting;
if (!semihosting) {
command_print(CMD, "semihosting not supported for current target");
return ERROR_FAIL;
}
if (!semihosting->is_active) {
command_print(CMD, "semihosting not yet enabled for current target");
return ERROR_FAIL;
}
if (CMD_ARGC > 0)
COMMAND_PARSE_ENABLE(CMD_ARGV[0], semihosting->is_fileio);
command_print(CMD, "semihosting fileio is %s",
semihosting->is_fileio
? "enabled" : "disabled");
return ERROR_OK;
}
static __COMMAND_HANDLER(handle_common_semihosting_cmdline)
{
struct target *target = get_current_target(CMD_CTX);
unsigned int i;
if (target == NULL) {
LOG_ERROR("No target selected");
return ERROR_FAIL;
}
struct semihosting *semihosting = target->semihosting;
if (!semihosting) {
command_print(CMD, "semihosting not supported for current target");
return ERROR_FAIL;
}
free(semihosting->cmdline);
semihosting->cmdline = CMD_ARGC > 0 ? strdup(CMD_ARGV[0]) : NULL;
for (i = 1; i < CMD_ARGC; i++) {
char *cmdline = alloc_printf("%s %s", semihosting->cmdline, CMD_ARGV[i]);
if (cmdline == NULL)
break;
free(semihosting->cmdline);
semihosting->cmdline = cmdline;
}
command_print(CMD, "semihosting command line is [%s]",
semihosting->cmdline);
return ERROR_OK;
}
static __COMMAND_HANDLER(handle_common_semihosting_resumable_exit_command)
{
struct target *target = get_current_target(CMD_CTX);
if (target == NULL) {
LOG_ERROR("No target selected");
return ERROR_FAIL;
}
struct semihosting *semihosting = target->semihosting;
if (!semihosting) {
command_print(CMD, "semihosting not supported for current target");
return ERROR_FAIL;
}
if (!semihosting->is_active) {
command_print(CMD, "semihosting not yet enabled for current target");
return ERROR_FAIL;
}
if (CMD_ARGC > 0)
COMMAND_PARSE_ENABLE(CMD_ARGV[0], semihosting->has_resumable_exit);
command_print(CMD, "semihosting resumable exit is %s",
semihosting->has_resumable_exit
? "enabled" : "disabled");
return ERROR_OK;
}
const struct command_registration semihosting_common_handlers[] = {
{
"semihosting",
.handler = handle_common_semihosting_command,
.mode = COMMAND_EXEC,
.usage = "['enable'|'disable']",
.help = "activate support for semihosting operations",
},
{
"semihosting_cmdline",
.handler = handle_common_semihosting_cmdline,
.mode = COMMAND_EXEC,
.usage = "arguments",
.help = "command line arguments to be passed to program",
},
{
"semihosting_fileio",
.handler = handle_common_semihosting_fileio_command,
.mode = COMMAND_EXEC,
.usage = "['enable'|'disable']",
.help = "activate support for semihosting fileio operations",
},
{
"semihosting_resexit",
.handler = handle_common_semihosting_resumable_exit_command,
.mode = COMMAND_EXEC,
.usage = "['enable'|'disable']",
.help = "activate support for semihosting resumable exit",
},
COMMAND_REGISTRATION_DONE
};
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