riot.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2015 by Daniel Krebs                                    *
 *   Daniel Krebs - github@daniel-krebs.net                                *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <helper/time_support.h>
#include <jtag/jtag.h>
#include "target/target.h"
#include "target/target_type.h"
#include "rtos.h"
#include "helper/log.h"
#include "helper/types.h"
#include "target/armv7m.h"
#include "rtos_riot_stackings.h"
 
static bool riot_detect_rtos(struct target *target);
static int riot_create(struct target *target);
static int riot_update_threads(struct rtos *rtos);
static int riot_get_thread_reg_list(struct rtos *rtos, int64_t thread_id,
    struct rtos_reg **reg_list, int *num_regs);
static int riot_get_symbol_list_to_lookup(struct symbol_table_elem *symbol_list[]);
 
struct riot_thread_state {
    int value;
    const char *desc;
};
 
/* refer RIOT sched.h */
static const struct riot_thread_state riot_thread_states[] = {
    { 0, "Stopped" },
    { 1, "Zombie" },
    { 2, "Sleeping" },
    { 3, "Blocked mutex" },
    { 4, "Blocked receive" },
    { 5, "Blocked send" },
    { 6, "Blocked reply" },
    { 7, "Blocked any flag" },
    { 8, "Blocked all flags" },
    { 9, "Blocked mbox" },
    { 10, "Blocked condition" },
    { 11, "Running" },
    { 12, "Pending" },
};
#define RIOT_NUM_STATES ARRAY_SIZE(riot_thread_states)
 
struct riot_params {
    const char *target_name;
    unsigned char thread_sp_offset;
    unsigned char thread_status_offset;
};
 
static const struct riot_params riot_params_list[] = {
    {
        "cortex_m",     /* target_name */
        0x00,                   /* thread_sp_offset */
        0x04,                   /* thread_status_offset */
    },
    {   /* STLink */
        "hla_target",       /* target_name */
        0x00,           /* thread_sp_offset */
        0x04,           /* thread_status_offset */
    }
};
#define RIOT_NUM_PARAMS ARRAY_SIZE(riot_params_list)
 
/* Initialize in riot_create() depending on architecture */
static const struct rtos_register_stacking *stacking_info;
 
enum riot_symbol_values {
    RIOT_THREADS_BASE = 0,
    RIOT_NUM_THREADS,
    RIOT_ACTIVE_PID,
    RIOT_MAX_THREADS,
    RIOT_NAME_OFFSET,
};
 
struct riot_symbol {
    const char *const name;
    bool optional;
};
 
/* refer RIOT core/sched.c */
static struct riot_symbol const riot_symbol_list[] = {
    {"sched_threads", false},
    {"sched_num_threads", false},
    {"sched_active_pid", false},
    {"max_threads", false},
    {"_tcb_name_offset", true},
    {NULL, false}
};
 
const struct rtos_type riot_rtos = {
    .name = "RIOT",
    .detect_rtos = riot_detect_rtos,
    .create = riot_create,
    .update_threads = riot_update_threads,
    .get_thread_reg_list = riot_get_thread_reg_list,
    .get_symbol_list_to_lookup = riot_get_symbol_list_to_lookup,
};
 
static int riot_update_threads(struct rtos *rtos)
{
    int retval;
    int tasks_found = 0;
    const struct riot_params *param;
 
    if (!rtos)
        return ERROR_FAIL;
 
    if (!rtos->rtos_specific_params)
        return ERROR_FAIL;
 
    param = (const struct riot_params *)rtos->rtos_specific_params;
 
    if (!rtos->symbols) {
        LOG_ERROR("No symbols for RIOT");
        return ERROR_FAIL;
    }
 
    if (rtos->symbols[RIOT_THREADS_BASE].address == 0) {
        LOG_ERROR("Can't find symbol `%s`",
            riot_symbol_list[RIOT_THREADS_BASE].name);
        return ERROR_FAIL;
    }
 
    /* wipe out previous thread details if any */
    rtos_free_threadlist(rtos);
 
    /* Reset values */
    rtos->current_thread = 0;
    rtos->thread_count = 0;
 
    /* read the current thread id */
    int16_t active_pid = 0;
    retval = target_read_u16(rtos->target,
            rtos->symbols[RIOT_ACTIVE_PID].address,
            (uint16_t *)&active_pid);
    if (retval != ERROR_OK) {
        LOG_ERROR("Can't read symbol `%s`",
            riot_symbol_list[RIOT_ACTIVE_PID].name);
        return retval;
    }
    rtos->current_thread = active_pid;
 
    /* read the current thread count
     * It's `int` in RIOT, but this is Cortex M* only anyway */
    int32_t thread_count = 0;
    retval = target_read_u16(rtos->target,
            rtos->symbols[RIOT_NUM_THREADS].address,
            (uint16_t *)&thread_count);
    if (retval != ERROR_OK) {
        LOG_ERROR("Can't read symbol `%s`",
            riot_symbol_list[RIOT_NUM_THREADS].name);
        return retval;
    }
 
    /* read the maximum number of threads */
    uint8_t max_threads = 0;
    retval = target_read_u8(rtos->target,
            rtos->symbols[RIOT_MAX_THREADS].address,
            &max_threads);
    if (retval != ERROR_OK) {
        LOG_ERROR("Can't read symbol `%s`",
            riot_symbol_list[RIOT_MAX_THREADS].name);
        return retval;
    }
    if (thread_count > max_threads) {
        LOG_ERROR("Thread count is invalid");
        return ERROR_FAIL;
    }
    rtos->thread_count = thread_count;
 
    /* Base address of thread array */
    uint32_t threads_base = rtos->symbols[RIOT_THREADS_BASE].address;
 
    /* Try to get the offset of tcb_t::name, if absent RIOT wasn't compiled
     * with DEVELHELP, so there are no thread names */
    uint8_t name_offset = 0;
    if (rtos->symbols[RIOT_NAME_OFFSET].address != 0) {
        retval = target_read_u8(rtos->target,
                rtos->symbols[RIOT_NAME_OFFSET].address,
                &name_offset);
        if (retval != ERROR_OK) {
            LOG_ERROR("Can't read symbol `%s`",
                riot_symbol_list[RIOT_NAME_OFFSET].name);
            return retval;
        }
    }
 
    /* Allocate memory for thread description */
    rtos->thread_details = calloc(thread_count, sizeof(struct thread_detail));
    if (!rtos->thread_details) {
        LOG_ERROR("RIOT: out of memory");
        return ERROR_FAIL;
    }
 
    /* Buffer for thread names, maximum to display is 32 */
    char buffer[32];
 
    for (unsigned int i = 0; i < max_threads; i++) {
        if (tasks_found == rtos->thread_count)
            break;
 
        /* get pointer to tcb_t */
        uint32_t tcb_pointer = 0;
        retval = target_read_u32(rtos->target,
                threads_base + (i * 4),
                &tcb_pointer);
        if (retval != ERROR_OK) {
            LOG_ERROR("Can't parse `%s`",
                riot_symbol_list[RIOT_THREADS_BASE].name);
            goto error;
        }
 
        if (tcb_pointer == 0) {
            /* PID unused */
            continue;
        }
 
        /* Index is PID */
        rtos->thread_details[tasks_found].threadid = i;
 
        /* read thread state */
        uint8_t status = 0;
        retval = target_read_u8(rtos->target,
                tcb_pointer + param->thread_status_offset,
                &status);
        if (retval != ERROR_OK) {
            LOG_ERROR("Can't parse `%s`",
                riot_symbol_list[RIOT_THREADS_BASE].name);
            goto error;
        }
 
        /* Search for state */
        unsigned int k;
        for (k = 0; k < RIOT_NUM_STATES; k++) {
            if (riot_thread_states[k].value == status)
                break;
        }
 
        /* Copy state string */
        if (k >= RIOT_NUM_STATES) {
            rtos->thread_details[tasks_found].extra_info_str =
            strdup("unknown state");
        } else {
            rtos->thread_details[tasks_found].extra_info_str =
            strdup(riot_thread_states[k].desc);
        }
 
        if (!rtos->thread_details[tasks_found].extra_info_str) {
            LOG_ERROR("RIOT: out of memory");
            retval = ERROR_FAIL;
            goto error;
        }
 
        /* Thread names are only available if compiled with DEVELHELP */
        if (name_offset != 0) {
            uint32_t name_pointer = 0;
            retval = target_read_u32(rtos->target,
                    tcb_pointer + name_offset,
                    &name_pointer);
            if (retval != ERROR_OK) {
                LOG_ERROR("Can't parse `%s`",
                    riot_symbol_list[RIOT_THREADS_BASE].name);
                goto error;
            }
 
            /* read thread name */
            retval = target_read_buffer(rtos->target,
                    name_pointer,
                    sizeof(buffer),
                    (uint8_t *)&buffer);
            if (retval != ERROR_OK) {
                LOG_ERROR("Can't parse `%s`",
                    riot_symbol_list[RIOT_THREADS_BASE].name);
                goto error;
            }
 
            /* Make sure the string in the buffer terminates */
            if (buffer[sizeof(buffer) - 1] != 0)
                buffer[sizeof(buffer) - 1] = 0;
 
            /* Copy thread name */
            rtos->thread_details[tasks_found].thread_name_str =
            strdup(buffer);
 
        } else {
            rtos->thread_details[tasks_found].thread_name_str =
            strdup("Enable DEVELHELP to see task names");
        }
 
        if (!rtos->thread_details[tasks_found].thread_name_str) {
            LOG_ERROR("RIOT: out of memory");
            retval = ERROR_FAIL;
            goto error;
        }
 
        rtos->thread_details[tasks_found].exists = true;
 
        tasks_found++;
    }
 
    return ERROR_OK;
 
error:
    rtos_free_threadlist(rtos);
    return retval;
}
 
static int riot_get_thread_reg_list(struct rtos *rtos, int64_t thread_id,
        struct rtos_reg **reg_list, int *num_regs)
{
    int retval;
    const struct riot_params *param;
 
    if (!rtos)
        return ERROR_FAIL;
 
    if (thread_id == 0)
        return ERROR_FAIL;
 
    if (!rtos->rtos_specific_params)
        return ERROR_FAIL;
 
    param = (const struct riot_params *)rtos->rtos_specific_params;
 
    /* find the thread with given thread id */
    uint32_t threads_base = rtos->symbols[RIOT_THREADS_BASE].address;
    uint32_t tcb_pointer = 0;
    retval = target_read_u32(rtos->target,
            threads_base + (thread_id * 4),
            &tcb_pointer);
    if (retval != ERROR_OK) {
        LOG_ERROR("Can't parse `%s`", riot_symbol_list[RIOT_THREADS_BASE].name);
        return retval;
    }
 
    /* read stack pointer for that thread */
    uint32_t stackptr = 0;
    retval = target_read_u32(rtos->target,
            tcb_pointer + param->thread_sp_offset,
            &stackptr);
    if (retval != ERROR_OK) {
        LOG_ERROR("Can't parse `%s`", riot_symbol_list[RIOT_THREADS_BASE].name);
        return retval;
    }
 
    return rtos_generic_stack_read(rtos->target,
            stacking_info,
            stackptr,
            reg_list,
            num_regs);
}
 
static int riot_get_symbol_list_to_lookup(struct symbol_table_elem *symbol_list[])
{
    *symbol_list = calloc(ARRAY_SIZE(riot_symbol_list), sizeof(struct symbol_table_elem));
 
    if (!*symbol_list) {
        LOG_ERROR("RIOT: out of memory");
        return ERROR_FAIL;
    }
 
    for (unsigned int i = 0; i < ARRAY_SIZE(riot_symbol_list); i++) {
        (*symbol_list)[i].symbol_name = riot_symbol_list[i].name;
        (*symbol_list)[i].optional = riot_symbol_list[i].optional;
    }
 
    return ERROR_OK;
}
 
static bool riot_detect_rtos(struct target *target)
{
    if ((target->rtos->symbols) &&
        (target->rtos->symbols[RIOT_THREADS_BASE].address != 0)) {
        /* looks like RIOT */
        return true;
    }
    return false;
}
 
static int riot_create(struct target *target)
{
    unsigned int i = 0;
 
    /* lookup if target is supported by RIOT */
    while ((i < RIOT_NUM_PARAMS) &&
        (strcmp(riot_params_list[i].target_name, target->type->name) != 0)) {
        i++;
    }
    if (i >= RIOT_NUM_PARAMS) {
        LOG_ERROR("Could not find target in RIOT compatibility list");
        return ERROR_FAIL;
    }
 
    target->rtos->rtos_specific_params = (void *)&riot_params_list[i];
    target->rtos->current_thread = 0;
    target->rtos->thread_details = NULL;
 
    /* Stacking is different depending on architecture */
    struct armv7m_common *armv7m_target = target_to_armv7m(target);
 
    if (armv7m_target->arm.arch == ARM_ARCH_V6M)
        stacking_info = &rtos_riot_cortex_m0_stacking;
    else if (is_armv7m(armv7m_target))
        stacking_info = &rtos_riot_cortex_m34_stacking;
    else {
        LOG_ERROR("No stacking info for architecture");
        return ERROR_FAIL;
    }
    return ERROR_OK;
}