semihosting: User defined operation, Tcl command exec on host

Enabling a portion (0x100 - 0x107) of the user defined semihosting
operation number range (0x100 - 0x1FF) to be processed with the help of
the existing target event mechanism, to implement a general-purpose Tcl
interface for the target available on the host, via semihosting
interface.

Example usage:
- The user configures a Tcl command as a callback for one of the newly
	defined events (semihosting-user-cmd-0x10X) in the configuration
	file.
- The target can make a semihosting call with <opnum>, passing optional
	parameters for the call.

If there is no callback registered to the user defined operation number,
nothing happens.

Example usage: Configure RTT automatically with the exact, linked
control block location from target.

Signed-off-by: Zoltán Dudás <zedudi@gmail.com>
Change-Id: I10e1784b1fecd4e630d78df81cb44bf1aa2fc247
Reviewed-on: https://review.openocd.org/c/openocd/+/6748
Tested-by: jenkins
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
This commit is contained in:
Zoltán Dudás 2021-11-24 17:13:50 +01:00 committed by Antonio Borneo
parent dbbac5f11d
commit 5ab74bde06
7 changed files with 162 additions and 4 deletions

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@ -5185,6 +5185,22 @@ when reset disables PLLs needed to use a fast clock.
@* After single-step has completed @* After single-step has completed
@item @b{trace-config} @item @b{trace-config}
@* After target hardware trace configuration was changed @* After target hardware trace configuration was changed
@item @b{semihosting-user-cmd-0x100}
@* The target made a semihosting call with user-defined operation number 0x100
@item @b{semihosting-user-cmd-0x101}
@* The target made a semihosting call with user-defined operation number 0x101
@item @b{semihosting-user-cmd-0x102}
@* The target made a semihosting call with user-defined operation number 0x102
@item @b{semihosting-user-cmd-0x103}
@* The target made a semihosting call with user-defined operation number 0x103
@item @b{semihosting-user-cmd-0x104}
@* The target made a semihosting call with user-defined operation number 0x104
@item @b{semihosting-user-cmd-0x105}
@* The target made a semihosting call with user-defined operation number 0x105
@item @b{semihosting-user-cmd-0x106}
@* The target made a semihosting call with user-defined operation number 0x106
@item @b{semihosting-user-cmd-0x107}
@* The target made a semihosting call with user-defined operation number 0x107
@end itemize @end itemize
@quotation Note @quotation Note
@ -9241,6 +9257,17 @@ To make the SEMIHOSTING_SYS_EXIT call return normally, enable
this option (default: disabled). this option (default: disabled).
@end deffn @end deffn
@deffn {Command} {arm semihosting_read_user_param}
@cindex ARM semihosting
Read parameter of the semihosting call from the target. Usable in
semihosting-user-cmd-0x10* event handlers, returning a string.
When the target makes semihosting call with operation number from range 0x100-
0x107, an optional string parameter can be passed to the server. This parameter
is valid during the run of the event handlers and is accessible with this
command.
@end deffn
@section ARMv4 and ARMv5 Architecture @section ARMv4 and ARMv5 Architecture
@cindex ARMv4 @cindex ARMv4
@cindex ARMv5 @cindex ARMv5

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@ -367,10 +367,13 @@ int arm_semihosting(struct target *target, int *retval)
} }
/* Check for ARM operation numbers. */ /* Check for ARM operation numbers. */
if (semihosting->op >= 0 && semihosting->op <= 0x31) { if ((semihosting->op >= 0 && semihosting->op <= 0x31) ||
(semihosting->op >= 0x100 && semihosting->op <= 0x107)) {
*retval = semihosting_common(target); *retval = semihosting_common(target);
if (*retval != ERROR_OK) { if (*retval != ERROR_OK) {
LOG_ERROR("Failed semihosting operation (0x%02X)", semihosting->op); LOG_ERROR("Failed semihosting operation (0x%02X)",
semihosting->op);
return 0; return 0;
} }
} else { } else {

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@ -140,7 +140,9 @@ semihosting_result_t riscv_semihosting(struct target *target, int *retval)
semihosting->word_size_bytes = riscv_xlen(target) / 8; semihosting->word_size_bytes = riscv_xlen(target) / 8;
/* Check for ARM operation numbers. */ /* Check for ARM operation numbers. */
if (semihosting->op >= 0 && semihosting->op <= 0x31) { if ((semihosting->op >= 0 && semihosting->op <= 0x31) ||
(semihosting->op >= 0x100 && semihosting->op <= 0x107)) {
*retval = semihosting_common(target); *retval = semihosting_common(target);
if (*retval != ERROR_OK) { if (*retval != ERROR_OK) {
LOG_ERROR("Failed semihosting operation (0x%02X)", semihosting->op); LOG_ERROR("Failed semihosting operation (0x%02X)", semihosting->op);

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@ -154,6 +154,12 @@ int semihosting_common_init(struct target *target, void *setup,
return ERROR_OK; return ERROR_OK;
} }
/**
* User operation parameter string storage buffer. Contains valid data when the
* TARGET_EVENT_SEMIHOSTING_USER_CMD_xxxxx event callbacks are running.
*/
static char *semihosting_user_op_params;
/** /**
* Portable implementation of ARM semihosting calls. * Portable implementation of ARM semihosting calls.
* Performs the currently pending semihosting operation * Performs the currently pending semihosting operation
@ -183,7 +189,7 @@ int semihosting_common(struct target *target)
/* Enough space to hold 4 long words. */ /* Enough space to hold 4 long words. */
uint8_t fields[4*8]; uint8_t fields[4*8];
LOG_DEBUG("op=0x%x, param=0x%" PRIx64, (int)semihosting->op, LOG_DEBUG("op=0x%x, param=0x%" PRIx64, semihosting->op,
semihosting->param); semihosting->param);
switch (semihosting->op) { switch (semihosting->op) {
@ -1278,6 +1284,71 @@ int semihosting_common(struct target *target)
} }
break; break;
case SEMIHOSTING_USER_CMD_0x100 ... SEMIHOSTING_USER_CMD_0x107:
/**
* This is a user defined operation (while user cmds 0x100-0x1ff
* are possible, only 0x100-0x107 are currently implemented).
*
* Reads the user operation parameters from target, then fires the
* corresponding target event. When the target callbacks returned,
* cleans up the command parameter buffer.
*
* Entry
* On entry, the PARAMETER REGISTER contains a pointer to a
* two-field data block:
* - field 1 Contains a pointer to the bound command parameter
* string
* - field 2 Contains the command parameter string length
*
* Return
* On exit, the RETURN REGISTER contains the return status.
*/
{
assert(!semihosting_user_op_params);
retval = semihosting_read_fields(target, 2, fields);
if (retval != ERROR_OK) {
LOG_ERROR("Failed to read fields for user defined command"
" op=0x%x", semihosting->op);
return retval;
}
uint64_t addr = semihosting_get_field(target, 0, fields);
size_t len = semihosting_get_field(target, 1, fields);
if (len > SEMIHOSTING_MAX_TCL_COMMAND_FIELD_LENGTH) {
LOG_ERROR("The maximum length for user defined command "
"parameter is %u, received length is %zu (op=0x%x)",
SEMIHOSTING_MAX_TCL_COMMAND_FIELD_LENGTH,
len,
semihosting->op);
return ERROR_FAIL;
}
semihosting_user_op_params = malloc(len + 1);
if (!semihosting_user_op_params)
return ERROR_FAIL;
semihosting_user_op_params[len] = 0;
retval = target_read_buffer(target, addr, len,
(uint8_t *)(semihosting_user_op_params));
if (retval != ERROR_OK) {
LOG_ERROR("Failed to read from target, semihosting op=0x%x",
semihosting->op);
free(semihosting_user_op_params);
semihosting_user_op_params = NULL;
return retval;
}
target_handle_event(target, semihosting->op);
free(semihosting_user_op_params);
semihosting_user_op_params = NULL;
semihosting->result = 0;
break;
}
case SEMIHOSTING_SYS_ELAPSED: /* 0x30 */ case SEMIHOSTING_SYS_ELAPSED: /* 0x30 */
/* /*
* Returns the number of elapsed target ticks since execution * Returns the number of elapsed target ticks since execution
@ -1624,6 +1695,30 @@ COMMAND_HANDLER(handle_common_semihosting_resumable_exit_command)
return ERROR_OK; return ERROR_OK;
} }
COMMAND_HANDLER(handle_common_semihosting_read_user_param_command)
{
struct target *target = get_current_target(CMD_CTX);
struct semihosting *semihosting = target->semihosting;
if (CMD_ARGC)
return ERROR_COMMAND_SYNTAX_ERROR;
if (!semihosting->is_active) {
LOG_ERROR("semihosting not yet enabled for current target");
return ERROR_FAIL;
}
if (!semihosting_user_op_params) {
LOG_ERROR("This command is usable only from a registered user "
"semihosting event callback.");
return ERROR_FAIL;
}
command_print_sameline(CMD, "%s", semihosting_user_op_params);
return ERROR_OK;
}
const struct command_registration semihosting_common_handlers[] = { const struct command_registration semihosting_common_handlers[] = {
{ {
"semihosting", "semihosting",
@ -1653,5 +1748,12 @@ const struct command_registration semihosting_common_handlers[] = {
.usage = "['enable'|'disable']", .usage = "['enable'|'disable']",
.help = "activate support for semihosting resumable exit", .help = "activate support for semihosting resumable exit",
}, },
{
"semihosting_read_user_param",
.handler = handle_common_semihosting_read_user_param_command,
.mode = COMMAND_EXEC,
.usage = "",
.help = "read parameters in semihosting-user-cmd-0x10X callbacks",
},
COMMAND_REGISTRATION_DONE COMMAND_REGISTRATION_DONE
}; };

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@ -75,8 +75,14 @@ enum semihosting_operation_numbers {
SEMIHOSTING_SYS_WRITE = 0x05, SEMIHOSTING_SYS_WRITE = 0x05,
SEMIHOSTING_SYS_WRITEC = 0x03, SEMIHOSTING_SYS_WRITEC = 0x03,
SEMIHOSTING_SYS_WRITE0 = 0x04, SEMIHOSTING_SYS_WRITE0 = 0x04,
SEMIHOSTING_USER_CMD_0x100 = 0x100, /* First user cmd op code */
SEMIHOSTING_USER_CMD_0x107 = 0x107, /* Last supported user cmd op code */
SEMIHOSTING_USER_CMD_0x1FF = 0x1FF, /* Last user cmd op code */
}; };
/** Maximum allowed Tcl command segment length in bytes*/
#define SEMIHOSTING_MAX_TCL_COMMAND_FIELD_LENGTH (1024 * 1024)
/* /*
* Codes used by SEMIHOSTING_SYS_EXIT (formerly * Codes used by SEMIHOSTING_SYS_EXIT (formerly
* SEMIHOSTING_REPORT_EXCEPTION). * SEMIHOSTING_REPORT_EXCEPTION).

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@ -236,6 +236,15 @@ static const struct jim_nvp nvp_target_event[] = {
{ .value = TARGET_EVENT_TRACE_CONFIG, .name = "trace-config" }, { .value = TARGET_EVENT_TRACE_CONFIG, .name = "trace-config" },
{ .value = TARGET_EVENT_SEMIHOSTING_USER_CMD_0x100, .name = "semihosting-user-cmd-0x100" },
{ .value = TARGET_EVENT_SEMIHOSTING_USER_CMD_0x101, .name = "semihosting-user-cmd-0x101" },
{ .value = TARGET_EVENT_SEMIHOSTING_USER_CMD_0x102, .name = "semihosting-user-cmd-0x102" },
{ .value = TARGET_EVENT_SEMIHOSTING_USER_CMD_0x103, .name = "semihosting-user-cmd-0x103" },
{ .value = TARGET_EVENT_SEMIHOSTING_USER_CMD_0x104, .name = "semihosting-user-cmd-0x104" },
{ .value = TARGET_EVENT_SEMIHOSTING_USER_CMD_0x105, .name = "semihosting-user-cmd-0x105" },
{ .value = TARGET_EVENT_SEMIHOSTING_USER_CMD_0x106, .name = "semihosting-user-cmd-0x106" },
{ .value = TARGET_EVENT_SEMIHOSTING_USER_CMD_0x107, .name = "semihosting-user-cmd-0x107" },
{ .name = NULL, .value = -1 } { .name = NULL, .value = -1 }
}; };

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@ -294,6 +294,15 @@ enum target_event {
TARGET_EVENT_GDB_FLASH_WRITE_END, TARGET_EVENT_GDB_FLASH_WRITE_END,
TARGET_EVENT_TRACE_CONFIG, TARGET_EVENT_TRACE_CONFIG,
TARGET_EVENT_SEMIHOSTING_USER_CMD_0x100 = 0x100, /* semihosting allows user cmds from 0x100 to 0x1ff */
TARGET_EVENT_SEMIHOSTING_USER_CMD_0x101 = 0x101,
TARGET_EVENT_SEMIHOSTING_USER_CMD_0x102 = 0x102,
TARGET_EVENT_SEMIHOSTING_USER_CMD_0x103 = 0x103,
TARGET_EVENT_SEMIHOSTING_USER_CMD_0x104 = 0x104,
TARGET_EVENT_SEMIHOSTING_USER_CMD_0x105 = 0x105,
TARGET_EVENT_SEMIHOSTING_USER_CMD_0x106 = 0x106,
TARGET_EVENT_SEMIHOSTING_USER_CMD_0x107 = 0x107,
}; };
struct target_event_action { struct target_event_action {