rtos.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2011 by Broadcom Corporation                            *
 *   Evan Hunter - ehunter@broadcom.com                                    *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include "rtos.h"
#include "target/target.h"
#include "helper/log.h"
#include "helper/binarybuffer.h"
#include "server/gdb_server.h"
 
static const struct rtos_type *rtos_types[] = {
    &threadx_rtos,
    &freertos_rtos,
    &ecos_rtos,
    &linux_rtos,
    &chibios_rtos,
    &chromium_ec_rtos,
    &embkernel_rtos,
    &mqx_rtos,
    &ucos_iii_rtos,
    &nuttx_rtos,
    &riot_rtos,
    &zephyr_rtos,
    &rtkernel_rtos,
    /* keep this as last, as it always matches with rtos auto */
    &hwthread_rtos,
    NULL
};
 
static int rtos_try_next(struct target *target);
 
int rtos_smp_init(struct target *target)
{
    if (target->rtos->type->smp_init)
        return target->rtos->type->smp_init(target);
    return ERROR_TARGET_INIT_FAILED;
}
 
static int rtos_target_for_threadid(struct connection *connection, int64_t threadid, struct target **t)
{
    struct target *curr = get_target_from_connection(connection);
    if (t)
        *t = curr;
 
    return ERROR_OK;
}
 
static int os_alloc(struct target *target, const struct rtos_type *ostype)
{
    struct rtos *os = target->rtos = calloc(1, sizeof(struct rtos));
 
    if (!os)
        return JIM_ERR;
 
    os->type = ostype;
    os->current_threadid = -1;
    os->current_thread = 0;
    os->symbols = NULL;
    os->target = target;
 
    /* RTOS drivers can override the packet handler in _create(). */
    os->gdb_thread_packet = rtos_thread_packet;
    os->gdb_target_for_threadid = rtos_target_for_threadid;
 
    return JIM_OK;
}
 
static void os_free(struct target *target)
{
    if (!target->rtos)
        return;
 
    free(target->rtos->symbols);
    rtos_free_threadlist(target->rtos);
    free(target->rtos);
    target->rtos = NULL;
}
 
static int os_alloc_create(struct target *target, const struct rtos_type *ostype)
{
    int ret = os_alloc(target, ostype);
 
    if (ret == JIM_OK) {
        ret = target->rtos->type->create(target);
        if (ret != JIM_OK)
            os_free(target);
    }
 
    return ret;
}
 
int rtos_create(struct jim_getopt_info *goi, struct target *target)
{
    int x;
    const char *cp;
    Jim_Obj *res;
    int e;
 
    if (!goi->isconfigure && goi->argc != 0) {
        Jim_WrongNumArgs(goi->interp, goi->argc, goi->argv, "NO PARAMS");
        return JIM_ERR;
    }
 
    os_free(target);
 
    e = jim_getopt_string(goi, &cp, NULL);
    if (e != JIM_OK)
        return e;
 
    if (strcmp(cp, "none") == 0)
        return JIM_OK;
 
    if (strcmp(cp, "auto") == 0) {
        /* Auto detect tries to look up all symbols for each RTOS,
         * and runs the RTOS driver's _detect() function when GDB
         * finds all symbols for any RTOS. See rtos_qsymbol(). */
        target->rtos_auto_detect = true;
 
        /* rtos_qsymbol() will iterate over all RTOSes. Allocate
         * target->rtos here, and set it to the first RTOS type. */
        return os_alloc(target, rtos_types[0]);
    }
 
    for (x = 0; rtos_types[x]; x++)
        if (strcmp(cp, rtos_types[x]->name) == 0)
            return os_alloc_create(target, rtos_types[x]);
 
    Jim_SetResultFormatted(goi->interp, "Unknown RTOS type %s, try one of: ", cp);
    res = Jim_GetResult(goi->interp);
    for (x = 0; rtos_types[x]; x++)
        Jim_AppendStrings(goi->interp, res, rtos_types[x]->name, ", ", NULL);
    Jim_AppendStrings(goi->interp, res, ", auto or none", NULL);
 
    return JIM_ERR;
}
 
void rtos_destroy(struct target *target)
{
    os_free(target);
}
 
int gdb_thread_packet(struct connection *connection, char const *packet, int packet_size)
{
    struct target *target = get_target_from_connection(connection);
    if (!target->rtos)
        return rtos_thread_packet(connection, packet, packet_size); /* thread not
                                         *found*/
    return target->rtos->gdb_thread_packet(connection, packet, packet_size);
}
 
static struct symbol_table_elem *find_symbol(const struct rtos *os, const char *symbol)
{
    struct symbol_table_elem *s;
 
    for (s = os->symbols; s->symbol_name; s++)
        if (!strcmp(s->symbol_name, symbol))
            return s;
 
    return NULL;
}
 
static struct symbol_table_elem *next_symbol(struct rtos *os, char *cur_symbol, uint64_t cur_addr)
{
    if (!os->symbols)
        os->type->get_symbol_list_to_lookup(&os->symbols);
 
    if (!cur_symbol[0])
        return &os->symbols[0];
 
    struct symbol_table_elem *s = find_symbol(os, cur_symbol);
    if (!s)
        return NULL;
 
    s->address = cur_addr;
    s++;
    return s;
}
 
/* rtos_qsymbol() processes and replies to all qSymbol packets from GDB.
 *
 * GDB sends a qSymbol:: packet (empty address, empty name) to notify
 * that it can now answer qSymbol::hexcodedname queries, to look up symbols.
 *
 * If the qSymbol packet has no address that means GDB did not find the
 * symbol, in which case auto-detect will move on to try the next RTOS.
 *
 * rtos_qsymbol() then calls the next_symbol() helper function, which
 * iterates over symbol names for the current RTOS until it finds the
 * symbol in the received GDB packet, and then returns the next entry
 * in the list of symbols.
 *
 * If GDB replied about the last symbol for the RTOS and the RTOS was
 * specified explicitly, then no further symbol lookup is done. When
 * auto-detecting, the RTOS driver _detect() function must return success.
 *
 * The symbol is tried twice to handle the -flto case with gcc.  The first
 * attempt uses the symbol as-is, and the second attempt tries the symbol
 * with ".lto_priv.0" appended to it.  We only consider the first static
 * symbol here from the -flto case.  (Each subsequent static symbol with
 * the same name is exported as .lto_priv.1, .lto_priv.2, etc.)
 *
 * rtos_qsymbol() returns 1 if an RTOS has been detected, or 0 otherwise.
 */
int rtos_qsymbol(struct connection *connection, char const *packet, int packet_size)
{
    int rtos_detected = 0;
    uint64_t addr = 0;
    size_t reply_len;
    char reply[GDB_BUFFER_SIZE + 1], cur_sym[GDB_BUFFER_SIZE / 2 + 1] = ""; /* Extra byte for null-termination */
    struct symbol_table_elem *next_sym = NULL;
    struct target *target = get_target_from_connection(connection);
    struct rtos *os = target->rtos;
 
    reply_len = sprintf(reply, "OK");
 
    if (!os)
        goto done;
 
    /* Decode any symbol name in the packet*/
    size_t len = unhexify((uint8_t *)cur_sym, strchr(packet + 8, ':') + 1, strlen(strchr(packet + 8, ':') + 1));
    cur_sym[len] = 0;
 
    const char no_suffix[] = "";
    const char lto_suffix[] = ".lto_priv.0";
    const size_t lto_suffix_len = strlen(lto_suffix);
 
    const char *cur_suffix;
    const char *next_suffix;
 
    /* Detect what suffix was used during the previous symbol lookup attempt, and
     * speculatively determine the next suffix (only used for the unknown address case) */
    if (len > lto_suffix_len && !strcmp(cur_sym + len - lto_suffix_len, lto_suffix)) {
        /* Trim the suffix from cur_sym for comparison purposes below */
        cur_sym[len - lto_suffix_len] = '\0';
        cur_suffix = lto_suffix;
        next_suffix = NULL;
    } else {
        cur_suffix = no_suffix;
        next_suffix = lto_suffix;
    }
 
    if ((strcmp(packet, "qSymbol::") != 0) &&               /* GDB is not offering symbol lookup for the first time */
        (!sscanf(packet, "qSymbol:%" SCNx64 ":", &addr))) { /* GDB did not find an address for a symbol */
 
        /* GDB could not find an address for the previous symbol */
        struct symbol_table_elem *sym = find_symbol(os, cur_sym);
 
        if (next_suffix) {
            next_sym = sym;
        } else if (sym && !sym->optional) { /* the symbol is mandatory for this RTOS */
            if (!target->rtos_auto_detect) {
                LOG_WARNING("RTOS %s not detected. (GDB could not find symbol \'%s\')", os->type->name, cur_sym);
                goto done;
            } else {
                /* Autodetecting RTOS - try next RTOS */
                if (!rtos_try_next(target)) {
                    LOG_WARNING("No RTOS could be auto-detected!");
                    goto done;
                }
 
                /* Next RTOS selected - invalidate current symbol */
                cur_sym[0] = '\x00';
            }
        }
    }
 
    LOG_DEBUG("RTOS: Address of symbol '%s%s' is 0x%" PRIx64, cur_sym, cur_suffix, addr);
 
    if (!next_sym) {
        next_sym = next_symbol(os, cur_sym, addr);
        next_suffix = no_suffix;
    }
 
    /* Should never happen unless the debugger misbehaves */
    if (!next_sym) {
        LOG_WARNING("RTOS: Debugger sent us qSymbol with '%s%s' that we did not ask for", cur_sym, cur_suffix);
        goto done;
    }
 
    if (!next_sym->symbol_name) {
        /* No more symbols need looking up */
 
        if (!target->rtos_auto_detect) {
            rtos_detected = 1;
            goto done;
        }
 
        if (os->type->detect_rtos(target)) {
            LOG_INFO("Auto-detected RTOS: %s", os->type->name);
            rtos_detected = 1;
            goto done;
        } else {
            LOG_WARNING("No RTOS could be auto-detected!");
            goto done;
        }
    }
 
    assert(next_suffix);
 
    reply_len = 8;                                   /* snprintf(..., "qSymbol:") */
    reply_len += 2 * strlen(next_sym->symbol_name);  /* hexify(..., next_sym->symbol_name, ...) */
    reply_len += 2 * strlen(next_suffix);            /* hexify(..., next_suffix, ...) */
    reply_len += 1;                                  /* Terminating NUL */
    if (reply_len > sizeof(reply)) {
        LOG_ERROR("ERROR: RTOS symbol '%s%s' name is too long for GDB!", next_sym->symbol_name, next_suffix);
        goto done;
    }
 
    LOG_DEBUG("RTOS: Requesting symbol lookup of '%s%s' from the debugger", next_sym->symbol_name, next_suffix);
 
    reply_len = snprintf(reply, sizeof(reply), "qSymbol:");
    reply_len += hexify(reply + reply_len,
        (const uint8_t *)next_sym->symbol_name, strlen(next_sym->symbol_name),
        sizeof(reply) - reply_len);
    reply_len += hexify(reply + reply_len,
        (const uint8_t *)next_suffix, strlen(next_suffix),
        sizeof(reply) - reply_len);
 
done:
    gdb_put_packet(connection, reply, reply_len);
    return rtos_detected;
}
 
int rtos_thread_packet(struct connection *connection, char const *packet, int packet_size)
{
    struct target *target = get_target_from_connection(connection);
 
    if (strncmp(packet, "qThreadExtraInfo,", 17) == 0) {
        if ((target->rtos) && (target->rtos->thread_details) &&
                (target->rtos->thread_count != 0)) {
            threadid_t threadid = 0;
            int found = -1;
            sscanf(packet, "qThreadExtraInfo,%" SCNx64, &threadid);
 
            if ((target->rtos) && (target->rtos->thread_details)) {
                int thread_num;
                for (thread_num = 0; thread_num < target->rtos->thread_count; thread_num++) {
                    if (target->rtos->thread_details[thread_num].threadid == threadid) {
                        if (target->rtos->thread_details[thread_num].exists)
                            found = thread_num;
                    }
                }
            }
            if (found == -1) {
                gdb_put_packet(connection, "E01", 3);   /* thread not found */
                return ERROR_OK;
            }
 
            struct thread_detail *detail = &target->rtos->thread_details[found];
 
            int str_size = 0;
            if (detail->thread_name_str)
                str_size += strlen(detail->thread_name_str);
            if (detail->extra_info_str)
                str_size += strlen(detail->extra_info_str);
 
            char *tmp_str = calloc(str_size + 9, sizeof(char));
            char *tmp_str_ptr = tmp_str;
 
            if (detail->thread_name_str)
                tmp_str_ptr += sprintf(tmp_str_ptr, "Name: %s", detail->thread_name_str);
            if (detail->extra_info_str) {
                if (tmp_str_ptr != tmp_str)
                    tmp_str_ptr += sprintf(tmp_str_ptr, ", ");
                tmp_str_ptr += sprintf(tmp_str_ptr, "%s", detail->extra_info_str);
            }
 
            assert(strlen(tmp_str) ==
                (size_t) (tmp_str_ptr - tmp_str));
 
            char *hex_str = malloc(strlen(tmp_str) * 2 + 1);
            size_t pkt_len = hexify(hex_str, (const uint8_t *)tmp_str,
                strlen(tmp_str), strlen(tmp_str) * 2 + 1);
 
            gdb_put_packet(connection, hex_str, pkt_len);
            free(hex_str);
            free(tmp_str);
            return ERROR_OK;
 
        }
        gdb_put_packet(connection, "", 0);
        return ERROR_OK;
    } else if (strncmp(packet, "qSymbol", 7) == 0) {
        if (rtos_qsymbol(connection, packet, packet_size) == 1) {
            if (target->rtos_auto_detect) {
                target->rtos_auto_detect = false;
                target->rtos->type->create(target);
            }
            target->rtos->type->update_threads(target->rtos);
        }
        return ERROR_OK;
    } else if (strncmp(packet, "qfThreadInfo", 12) == 0) {
        int i;
        if (target->rtos) {
            if (target->rtos->thread_count == 0) {
                gdb_put_packet(connection, "l", 1);
            } else {
                /*thread id are 16 char +1 for ',' */
                char *out_str = malloc(17 * target->rtos->thread_count + 1);
                char *tmp_str = out_str;
                for (i = 0; i < target->rtos->thread_count; i++) {
                    tmp_str += sprintf(tmp_str, "%c%016" PRIx64, i == 0 ? 'm' : ',',
                                        target->rtos->thread_details[i].threadid);
                }
                gdb_put_packet(connection, out_str, strlen(out_str));
                free(out_str);
            }
        } else
            gdb_put_packet(connection, "l", 1);
 
        return ERROR_OK;
    } else if (strncmp(packet, "qsThreadInfo", 12) == 0) {
        gdb_put_packet(connection, "l", 1);
        return ERROR_OK;
    } else if (strncmp(packet, "qAttached", 9) == 0) {
        gdb_put_packet(connection, "1", 1);
        return ERROR_OK;
    } else if (strncmp(packet, "qOffsets", 8) == 0) {
        char offsets[] = "Text=0;Data=0;Bss=0";
        gdb_put_packet(connection, offsets, sizeof(offsets)-1);
        return ERROR_OK;
    } else if (strncmp(packet, "qCRC:", 5) == 0) {
        /* make sure we check this before "qC" packet below
         * otherwise it gets incorrectly handled */
        return GDB_THREAD_PACKET_NOT_CONSUMED;
    } else if (strncmp(packet, "qC", 2) == 0) {
        if (target->rtos) {
            char buffer[19];
            int size;
            size = snprintf(buffer, 19, "QC%016" PRIx64, target->rtos->current_thread);
            gdb_put_packet(connection, buffer, size);
        } else
            gdb_put_packet(connection, "QC0", 3);
        return ERROR_OK;
    } else if (packet[0] == 'T') {  /* Is thread alive? */
        threadid_t threadid;
        int found = -1;
        sscanf(packet, "T%" SCNx64, &threadid);
        if ((target->rtos) && (target->rtos->thread_details)) {
            int thread_num;
            for (thread_num = 0; thread_num < target->rtos->thread_count; thread_num++) {
                if (target->rtos->thread_details[thread_num].threadid == threadid) {
                    if (target->rtos->thread_details[thread_num].exists)
                        found = thread_num;
                }
            }
        }
        if (found != -1)
            gdb_put_packet(connection, "OK", 2);    /* thread alive */
        else
            gdb_put_packet(connection, "E01", 3);   /* thread not found */
        return ERROR_OK;
    } else if (packet[0] == 'H') {  /* Set current thread ( 'c' for step and continue, 'g' for
                     * all other operations ) */
        if ((packet[1] == 'g') && (target->rtos)) {
            threadid_t threadid;
            sscanf(packet, "Hg%16" SCNx64, &threadid);
            LOG_DEBUG("RTOS: GDB requested to set current thread to 0x%" PRIx64, threadid);
            /* threadid of 0 indicates target should choose */
            if (threadid == 0)
                target->rtos->current_threadid = target->rtos->current_thread;
            else
                target->rtos->current_threadid = threadid;
        }
        gdb_put_packet(connection, "OK", 2);
        return ERROR_OK;
    }
 
    return GDB_THREAD_PACKET_NOT_CONSUMED;
}
 
static int rtos_put_gdb_reg_list(struct connection *connection,
        struct rtos_reg *reg_list, int num_regs)
{
    size_t num_bytes = 1; /* NUL */
    for (int i = 0; i < num_regs; ++i)
        num_bytes += DIV_ROUND_UP(reg_list[i].size, 8) * 2;
 
    char *hex = malloc(num_bytes);
    char *hex_p = hex;
 
    for (int i = 0; i < num_regs; ++i) {
        size_t count = DIV_ROUND_UP(reg_list[i].size, 8);
        size_t n = hexify(hex_p, reg_list[i].value, count, num_bytes);
        hex_p += n;
        num_bytes -= n;
    }
 
    gdb_put_packet(connection, hex, strlen(hex));
    free(hex);
 
    return ERROR_OK;
}
 
int rtos_get_gdb_reg(struct connection *connection, int reg_num)
{
    struct target *target = get_target_from_connection(connection);
    int64_t current_threadid = target->rtos->current_threadid;
    if ((target->rtos) && (current_threadid != -1) &&
            (current_threadid != 0) &&
            ((current_threadid != target->rtos->current_thread) ||
            (target->smp))) {   /* in smp several current thread are possible */
        struct rtos_reg *reg_list;
        int num_regs;
 
        LOG_DEBUG("getting register %d for thread 0x%" PRIx64
                  ", target->rtos->current_thread=0x%" PRIx64,
                                        reg_num,
                                        current_threadid,
                                        target->rtos->current_thread);
 
        int retval;
        if (target->rtos->type->get_thread_reg) {
            reg_list = calloc(1, sizeof(*reg_list));
            num_regs = 1;
            retval = target->rtos->type->get_thread_reg(target->rtos,
                    current_threadid, reg_num, &reg_list[0]);
            if (retval != ERROR_OK) {
                LOG_ERROR("RTOS: failed to get register %d", reg_num);
                return retval;
            }
        } else {
            retval = target->rtos->type->get_thread_reg_list(target->rtos,
                    current_threadid,
                    &reg_list,
                    &num_regs);
            if (retval != ERROR_OK) {
                LOG_ERROR("RTOS: failed to get register list");
                return retval;
            }
        }
 
        for (int i = 0; i < num_regs; ++i) {
            if (reg_list[i].number == (uint32_t)reg_num) {
                rtos_put_gdb_reg_list(connection, reg_list + i, 1);
                free(reg_list);
                return ERROR_OK;
            }
        }
 
        free(reg_list);
    }
    return ERROR_FAIL;
}
 
int rtos_get_gdb_reg_list(struct connection *connection)
{
    struct target *target = get_target_from_connection(connection);
    int64_t current_threadid = target->rtos->current_threadid;
    if ((target->rtos) && (current_threadid != -1) &&
            (current_threadid != 0) &&
            ((current_threadid != target->rtos->current_thread) ||
            (target->smp))) {   /* in smp several current thread are possible */
        struct rtos_reg *reg_list;
        int num_regs;
 
        LOG_DEBUG("RTOS: getting register list for thread 0x%" PRIx64
                  ", target->rtos->current_thread=0x%" PRIx64 "\r\n",
                                        current_threadid,
                                        target->rtos->current_thread);
 
        int retval = target->rtos->type->get_thread_reg_list(target->rtos,
                current_threadid,
                &reg_list,
                &num_regs);
        if (retval != ERROR_OK) {
            LOG_ERROR("RTOS: failed to get register list");
            return retval;
        }
 
        rtos_put_gdb_reg_list(connection, reg_list, num_regs);
        free(reg_list);
 
        return ERROR_OK;
    }
    return ERROR_FAIL;
}
 
int rtos_set_reg(struct connection *connection, int reg_num,
        uint8_t *reg_value)
{
    struct target *target = get_target_from_connection(connection);
    int64_t current_threadid = target->rtos->current_threadid;
    if ((target->rtos) &&
            (target->rtos->type->set_reg) &&
            (current_threadid != -1) &&
            (current_threadid != 0)) {
        return target->rtos->type->set_reg(target->rtos, reg_num, reg_value);
    }
    return ERROR_FAIL;
}
 
int rtos_generic_stack_read(struct target *target,
    const struct rtos_register_stacking *stacking,
    int64_t stack_ptr,
    struct rtos_reg **reg_list,
    int *num_regs)
{
    int retval;
 
    if (stack_ptr == 0) {
        LOG_ERROR("Error: null stack pointer in thread");
        return -5;
    }
    /* Read the stack */
    uint8_t *stack_data = malloc(stacking->stack_registers_size);
    uint32_t address = stack_ptr;
 
    if (stacking->stack_growth_direction == 1)
        address -= stacking->stack_registers_size;
    if (stacking->read_stack)
        retval = stacking->read_stack(target, address, stacking, stack_data);
    else
        retval = target_read_buffer(target, address, stacking->stack_registers_size, stack_data);
    if (retval != ERROR_OK) {
        free(stack_data);
        LOG_ERROR("Error reading stack frame from thread");
        return retval;
    }
    LOG_DEBUG("RTOS: Read stack frame at 0x%" PRIx32, address);
 
#if 0
        LOG_OUTPUT("Stack Data :");
        for (i = 0; i < stacking->stack_registers_size; i++)
            LOG_OUTPUT("%02X", stack_data[i]);
        LOG_OUTPUT("\r\n");
#endif
 
    target_addr_t new_stack_ptr;
    if (stacking->calculate_process_stack) {
        new_stack_ptr = stacking->calculate_process_stack(target,
                stack_data, stacking, stack_ptr);
    } else {
        new_stack_ptr = stack_ptr - stacking->stack_growth_direction *
            stacking->stack_registers_size;
    }
 
    *reg_list = calloc(stacking->num_output_registers, sizeof(struct rtos_reg));
    *num_regs = stacking->num_output_registers;
 
    for (int i = 0; i < stacking->num_output_registers; ++i) {
        (*reg_list)[i].number = stacking->register_offsets[i].number;
        (*reg_list)[i].size = stacking->register_offsets[i].width_bits;
 
        int offset = stacking->register_offsets[i].offset;
        if (offset == -2)
            buf_cpy(&new_stack_ptr, (*reg_list)[i].value, (*reg_list)[i].size);
        else if (offset != -1)
            buf_cpy(stack_data + offset, (*reg_list)[i].value, (*reg_list)[i].size);
    }
 
    free(stack_data);
/*  LOG_OUTPUT("Output register string: %s\r\n", *hex_reg_list); */
    return ERROR_OK;
}
 
static int rtos_try_next(struct target *target)
{
    struct rtos *os = target->rtos;
    const struct rtos_type **type = rtos_types;
 
    if (!os)
        return 0;
 
    while (*type && os->type != *type)
        type++;
 
    if (!*type || !*(++type))
        return 0;
 
    os->type = *type;
 
    free(os->symbols);
    os->symbols = NULL;
 
    return 1;
}
 
int rtos_update_threads(struct target *target)
{
    if ((target->rtos) && (target->rtos->type))
        target->rtos->type->update_threads(target->rtos);
    return ERROR_OK;
}
 
void rtos_free_threadlist(struct rtos *rtos)
{
    if (rtos->thread_details) {
        int j;
 
        for (j = 0; j < rtos->thread_count; j++) {
            struct thread_detail *current_thread = &rtos->thread_details[j];
            free(current_thread->thread_name_str);
            free(current_thread->extra_info_str);
        }
        free(rtos->thread_details);
        rtos->thread_details = NULL;
        rtos->thread_count = 0;
        rtos->current_threadid = -1;
        rtos->current_thread = 0;
    }
}
 
int rtos_read_buffer(struct target *target, target_addr_t address,
        uint32_t size, uint8_t *buffer)
{
    if (target->rtos->type->read_buffer)
        return target->rtos->type->read_buffer(target->rtos, address, size, buffer);
    return ERROR_NOT_IMPLEMENTED;
}
 
int rtos_write_buffer(struct target *target, target_addr_t address,
        uint32_t size, const uint8_t *buffer)
{
    if (target->rtos->type->write_buffer)
        return target->rtos->type->write_buffer(target->rtos, address, size, buffer);
    return ERROR_NOT_IMPLEMENTED;
}