FreeRTOS.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 <helper/time_support.h>
#include <jtag/jtag.h>
#include "target/target.h"
#include "rtos.h"
#include "helper/log.h"
#include "helper/types.h"
#include "rtos_standard_stackings.h"
#include "target/armv7m.h"
#include "target/cortex_m.h"
 
#define FREERTOS_MAX_PRIORITIES 63
 
/* FIXME: none of the _width parameters are actually observed properly!
 * you WILL need to edit more if you actually attempt to target a 8/16/64
 * bit target!
 */
 
struct freertos_params {
    const char *target_name;
    const unsigned char thread_count_width;
    const unsigned char pointer_width;
    const unsigned char list_next_offset;
    const unsigned char list_width;
    const unsigned char list_elem_next_offset;
    const unsigned char list_elem_content_offset;
    const unsigned char thread_stack_offset;
    const unsigned char thread_name_offset;
    const struct rtos_register_stacking *stacking_info_cm3;
    const struct rtos_register_stacking *stacking_info_cm4f;
    const struct rtos_register_stacking *stacking_info_cm4f_fpu;
};
 
static const struct freertos_params freertos_params_list[] = {
    {
    "cortex_m",         /* target_name */
    4,                      /* thread_count_width; */
    4,                      /* pointer_width; */
    16,                     /* list_next_offset; */
    20,                     /* list_width; */
    8,                      /* list_elem_next_offset; */
    12,                     /* list_elem_content_offset */
    0,                      /* thread_stack_offset; */
    52,                     /* thread_name_offset; */
    &rtos_standard_cortex_m3_stacking,  /* stacking_info */
    &rtos_standard_cortex_m4f_stacking,
    &rtos_standard_cortex_m4f_fpu_stacking,
    },
    {
    "hla_target",           /* target_name */
    4,                      /* thread_count_width; */
    4,                      /* pointer_width; */
    16,                     /* list_next_offset; */
    20,                     /* list_width; */
    8,                      /* list_elem_next_offset; */
    12,                     /* list_elem_content_offset */
    0,                      /* thread_stack_offset; */
    52,                     /* thread_name_offset; */
    &rtos_standard_cortex_m3_stacking,  /* stacking_info */
    &rtos_standard_cortex_m4f_stacking,
    &rtos_standard_cortex_m4f_fpu_stacking,
    },
};
 
static bool freertos_detect_rtos(struct target *target);
static int freertos_create(struct target *target);
static int freertos_update_threads(struct rtos *rtos);
static int freertos_get_thread_reg_list(struct rtos *rtos, int64_t thread_id,
        struct rtos_reg **reg_list, int *num_regs);
static int freertos_get_symbol_list_to_lookup(struct symbol_table_elem *symbol_list[]);
 
const struct rtos_type freertos_rtos = {
    .name = "FreeRTOS",
 
    .detect_rtos = freertos_detect_rtos,
    .create = freertos_create,
    .update_threads = freertos_update_threads,
    .get_thread_reg_list = freertos_get_thread_reg_list,
    .get_symbol_list_to_lookup = freertos_get_symbol_list_to_lookup,
};
 
enum freertos_symbol_values {
    FREERTOS_VAL_PX_CURRENT_TCB = 0,
    FREERTOS_VAL_PX_READY_TASKS_LISTS = 1,
    FREERTOS_VAL_X_DELAYED_TASK_LIST1 = 2,
    FREERTOS_VAL_X_DELAYED_TASK_LIST2 = 3,
    FREERTOS_VAL_PX_DELAYED_TASK_LIST = 4,
    FREERTOS_VAL_PX_OVERFLOW_DELAYED_TASK_LIST = 5,
    FREERTOS_VAL_X_PENDING_READY_LIST = 6,
    FREERTOS_VAL_X_TASKS_WAITING_TERMINATION = 7,
    FREERTOS_VAL_X_SUSPENDED_TASK_LIST = 8,
    FREERTOS_VAL_UX_CURRENT_NUMBER_OF_TASKS = 9,
    FREERTOS_VAL_UX_TOP_USED_PRIORITY = 10,
    FREERTOS_VAL_X_SCHEDULER_RUNNING = 11,
};
 
struct symbols {
    const char *name;
    bool optional;
};
 
static const struct symbols freertos_symbol_list[] = {
    { "pxCurrentTCB", false },
    { "pxReadyTasksLists", false },
    { "xDelayedTaskList1", false },
    { "xDelayedTaskList2", false },
    { "pxDelayedTaskList", false },
    { "pxOverflowDelayedTaskList", false },
    { "xPendingReadyList", false },
    { "xTasksWaitingTermination", true }, /* Only if INCLUDE_vTaskDelete */
    { "xSuspendedTaskList", true }, /* Only if INCLUDE_vTaskSuspend */
    { "uxCurrentNumberOfTasks", false },
    { "uxTopUsedPriority", true }, /* Unavailable since v7.5.3 */
    { "xSchedulerRunning", false },
    { NULL, false }
};
 
/* TODO: */
/* this is not safe for little endian yet */
/* may be problems reading if sizes are not 32 bit long integers. */
/* test mallocs for failure */
 
static int freertos_update_threads(struct rtos *rtos)
{
    int retval;
    unsigned int tasks_found = 0;
    const struct freertos_params *param;
 
    if (!rtos->rtos_specific_params)
        return -1;
 
    param = (const struct freertos_params *) rtos->rtos_specific_params;
 
    if (!rtos->symbols) {
        LOG_ERROR("No symbols for FreeRTOS");
        return -3;
    }
 
    if (rtos->symbols[FREERTOS_VAL_UX_CURRENT_NUMBER_OF_TASKS].address == 0) {
        LOG_ERROR("Don't have the number of threads in FreeRTOS");
        return -2;
    }
 
    uint32_t thread_list_size = 0;
    retval = target_read_u32(rtos->target,
            rtos->symbols[FREERTOS_VAL_UX_CURRENT_NUMBER_OF_TASKS].address,
            &thread_list_size);
    LOG_DEBUG("FreeRTOS: Read uxCurrentNumberOfTasks at 0x%" PRIx64 ", value %" PRIu32,
                                        rtos->symbols[FREERTOS_VAL_UX_CURRENT_NUMBER_OF_TASKS].address,
                                        thread_list_size);
 
    if (retval != ERROR_OK) {
        LOG_ERROR("Could not read FreeRTOS thread count from target");
        return retval;
    }
 
    /* wipe out previous thread details if any */
    rtos_free_threadlist(rtos);
 
    /* read the current thread */
    uint32_t pointer_casts_are_bad;
    retval = target_read_u32(rtos->target,
            rtos->symbols[FREERTOS_VAL_PX_CURRENT_TCB].address,
            &pointer_casts_are_bad);
    if (retval != ERROR_OK) {
        LOG_ERROR("Error reading current thread in FreeRTOS thread list");
        return retval;
    }
    rtos->current_thread = pointer_casts_are_bad;
    LOG_DEBUG("FreeRTOS: Read pxCurrentTCB at 0x%" PRIx64 ", value 0x%" PRIx64,
                                        rtos->symbols[FREERTOS_VAL_PX_CURRENT_TCB].address,
                                        rtos->current_thread);
 
    /* read scheduler running */
    uint32_t scheduler_running;
    retval = target_read_u32(rtos->target,
            rtos->symbols[FREERTOS_VAL_X_SCHEDULER_RUNNING].address,
            &scheduler_running);
    if (retval != ERROR_OK) {
        LOG_ERROR("Error reading FreeRTOS scheduler state");
        return retval;
    }
    LOG_DEBUG("FreeRTOS: Read xSchedulerRunning at 0x%" PRIx64 ", value 0x%" PRIx32,
                                        rtos->symbols[FREERTOS_VAL_X_SCHEDULER_RUNNING].address,
                                        scheduler_running);
 
    if ((thread_list_size  == 0) || (rtos->current_thread == 0) || (scheduler_running != 1)) {
        /* Either : No RTOS threads - there is always at least the current execution though */
        /* OR     : No current thread - all threads suspended - show the current execution
         * of idling */
        char tmp_str[] = "Current Execution";
        thread_list_size++;
        tasks_found++;
        rtos->thread_details = malloc(
                sizeof(struct thread_detail) * thread_list_size);
        if (!rtos->thread_details) {
            LOG_ERROR("Error allocating memory for %d threads", thread_list_size);
            return ERROR_FAIL;
        }
        rtos->current_thread = 1;
        rtos->thread_details->threadid = rtos->current_thread;
        rtos->thread_details->exists = true;
        rtos->thread_details->extra_info_str = NULL;
        rtos->thread_details->thread_name_str = malloc(sizeof(tmp_str));
        strcpy(rtos->thread_details->thread_name_str, tmp_str);
 
        if (thread_list_size == 1) {
            rtos->thread_count = 1;
            return ERROR_OK;
        }
    } else {
        /* create space for new thread details */
        rtos->thread_details = malloc(
                sizeof(struct thread_detail) * thread_list_size);
        if (!rtos->thread_details) {
            LOG_ERROR("Error allocating memory for %d threads", thread_list_size);
            return ERROR_FAIL;
        }
    }
 
    /* Find out how many lists are needed to be read from pxReadyTasksLists, */
    if (rtos->symbols[FREERTOS_VAL_UX_TOP_USED_PRIORITY].address == 0) {
        LOG_ERROR("FreeRTOS: uxTopUsedPriority is not defined, consult the OpenOCD manual for a work-around");
        return ERROR_FAIL;
    }
    uint32_t top_used_priority = 0;
    retval = target_read_u32(rtos->target,
            rtos->symbols[FREERTOS_VAL_UX_TOP_USED_PRIORITY].address,
            &top_used_priority);
    if (retval != ERROR_OK)
        return retval;
    LOG_DEBUG("FreeRTOS: Read uxTopUsedPriority at 0x%" PRIx64 ", value %" PRIu32,
                                        rtos->symbols[FREERTOS_VAL_UX_TOP_USED_PRIORITY].address,
                                        top_used_priority);
    if (top_used_priority > FREERTOS_MAX_PRIORITIES) {
        LOG_ERROR("FreeRTOS top used priority is unreasonably big, not proceeding: %" PRIu32,
            top_used_priority);
        return ERROR_FAIL;
    }
 
    /* uxTopUsedPriority was defined as configMAX_PRIORITIES - 1
     * in old FreeRTOS versions (before V7.5.3)
     * Use contrib/rtos-helpers/FreeRTOS-openocd.c to get compatible symbol
     * in newer FreeRTOS versions.
     * Here we restore the original configMAX_PRIORITIES value */
    unsigned int config_max_priorities = top_used_priority + 1;
 
    symbol_address_t *list_of_lists =
        malloc(sizeof(symbol_address_t) * (config_max_priorities + 5));
    if (!list_of_lists) {
        LOG_ERROR("Error allocating memory for %u priorities", config_max_priorities);
        return ERROR_FAIL;
    }
 
    unsigned int num_lists;
    for (num_lists = 0; num_lists < config_max_priorities; num_lists++)
        list_of_lists[num_lists] = rtos->symbols[FREERTOS_VAL_PX_READY_TASKS_LISTS].address +
            num_lists * param->list_width;
 
    list_of_lists[num_lists++] = rtos->symbols[FREERTOS_VAL_X_DELAYED_TASK_LIST1].address;
    list_of_lists[num_lists++] = rtos->symbols[FREERTOS_VAL_X_DELAYED_TASK_LIST2].address;
    list_of_lists[num_lists++] = rtos->symbols[FREERTOS_VAL_X_PENDING_READY_LIST].address;
    list_of_lists[num_lists++] = rtos->symbols[FREERTOS_VAL_X_SUSPENDED_TASK_LIST].address;
    list_of_lists[num_lists++] = rtos->symbols[FREERTOS_VAL_X_TASKS_WAITING_TERMINATION].address;
 
    for (unsigned int i = 0; i < num_lists; i++) {
        if (list_of_lists[i] == 0)
            continue;
 
        /* Read the number of threads in this list */
        uint32_t list_thread_count = 0;
        retval = target_read_u32(rtos->target,
                list_of_lists[i],
                &list_thread_count);
        if (retval != ERROR_OK) {
            LOG_ERROR("Error reading number of threads in FreeRTOS thread list");
            free(list_of_lists);
            return retval;
        }
        LOG_DEBUG("FreeRTOS: Read thread count for list %u at 0x%" PRIx64 ", value %" PRIu32,
                                        i, list_of_lists[i], list_thread_count);
 
        if (list_thread_count == 0)
            continue;
 
        /* Read the location of first list item */
        uint32_t prev_list_elem_ptr = -1;
        uint32_t list_elem_ptr = 0;
        retval = target_read_u32(rtos->target,
                list_of_lists[i] + param->list_next_offset,
                &list_elem_ptr);
        if (retval != ERROR_OK) {
            LOG_ERROR("Error reading first thread item location in FreeRTOS thread list");
            free(list_of_lists);
            return retval;
        }
        LOG_DEBUG("FreeRTOS: Read first item for list %u at 0x%" PRIx64 ", value 0x%" PRIx32,
                                        i, list_of_lists[i] + param->list_next_offset, list_elem_ptr);
 
        while ((list_thread_count > 0) && (list_elem_ptr != 0) &&
                (list_elem_ptr != prev_list_elem_ptr) &&
                (tasks_found < thread_list_size)) {
            /* Get the location of the thread structure. */
            retval = target_read_u32(rtos->target,
                    list_elem_ptr + param->list_elem_content_offset,
                    &pointer_casts_are_bad);
            if (retval != ERROR_OK) {
                LOG_ERROR("Error reading thread list item object in FreeRTOS thread list");
                free(list_of_lists);
                return retval;
            }
            rtos->thread_details[tasks_found].threadid = pointer_casts_are_bad;
            LOG_DEBUG("FreeRTOS: Read Thread ID at 0x%" PRIx32 ", value 0x%" PRIx64,
                                        list_elem_ptr + param->list_elem_content_offset,
                                        rtos->thread_details[tasks_found].threadid);
 
            /* get thread name */
 
            #define FREERTOS_THREAD_NAME_STR_SIZE (200)
            char tmp_str[FREERTOS_THREAD_NAME_STR_SIZE];
 
            /* Read the thread name */
            retval = target_read_buffer(rtos->target,
                    rtos->thread_details[tasks_found].threadid + param->thread_name_offset,
                    FREERTOS_THREAD_NAME_STR_SIZE,
                    (uint8_t *)&tmp_str);
            if (retval != ERROR_OK) {
                LOG_ERROR("Error reading first thread item location in FreeRTOS thread list");
                free(list_of_lists);
                return retval;
            }
            tmp_str[FREERTOS_THREAD_NAME_STR_SIZE-1] = '\x00';
            LOG_DEBUG("FreeRTOS: Read Thread Name at 0x%" PRIx64 ", value '%s'",
                                        rtos->thread_details[tasks_found].threadid + param->thread_name_offset,
                                        tmp_str);
 
            if (tmp_str[0] == '\x00')
                strcpy(tmp_str, "No Name");
 
            rtos->thread_details[tasks_found].thread_name_str =
                malloc(strlen(tmp_str)+1);
            strcpy(rtos->thread_details[tasks_found].thread_name_str, tmp_str);
            rtos->thread_details[tasks_found].exists = true;
 
            if (rtos->thread_details[tasks_found].threadid == rtos->current_thread) {
                char running_str[] = "State: Running";
                rtos->thread_details[tasks_found].extra_info_str = malloc(
                        sizeof(running_str));
                strcpy(rtos->thread_details[tasks_found].extra_info_str,
                    running_str);
            } else
                rtos->thread_details[tasks_found].extra_info_str = NULL;
 
            tasks_found++;
            list_thread_count--;
            rtos->thread_count = tasks_found;
 
            prev_list_elem_ptr = list_elem_ptr;
            list_elem_ptr = 0;
            retval = target_read_u32(rtos->target,
                    prev_list_elem_ptr + param->list_elem_next_offset,
                    &list_elem_ptr);
            if (retval != ERROR_OK) {
                LOG_ERROR("Error reading next thread item location in FreeRTOS thread list");
                free(list_of_lists);
                return retval;
            }
            LOG_DEBUG("FreeRTOS: Read next thread location at 0x%" PRIx32 ", value 0x%" PRIx32,
                                        prev_list_elem_ptr + param->list_elem_next_offset,
                                        list_elem_ptr);
        }
    }
 
    free(list_of_lists);
    return 0;
}
 
static int freertos_get_thread_reg_list(struct rtos *rtos, int64_t thread_id,
        struct rtos_reg **reg_list, int *num_regs)
{
    int retval;
    const struct freertos_params *param;
    int64_t stack_ptr = 0;
 
    if (!rtos)
        return -1;
 
    if (thread_id == 0)
        return -2;
 
    if (!rtos->rtos_specific_params)
        return -1;
 
    param = (const struct freertos_params *) rtos->rtos_specific_params;
 
    /* Read the stack pointer */
    uint32_t pointer_casts_are_bad;
    retval = target_read_u32(rtos->target,
            thread_id + param->thread_stack_offset,
            &pointer_casts_are_bad);
    if (retval != ERROR_OK) {
        LOG_ERROR("Error reading stack frame from FreeRTOS thread");
        return retval;
    }
    stack_ptr = pointer_casts_are_bad;
    LOG_DEBUG("FreeRTOS: Read stack pointer at 0x%" PRIx64 ", value 0x%" PRIx64,
                                        thread_id + param->thread_stack_offset,
                                        stack_ptr);
 
    /* Check for armv7m with *enabled* FPU, i.e. a Cortex-M4F */
    int cm4_fpu_enabled = 0;
    struct armv7m_common *armv7m_target = target_to_armv7m(rtos->target);
    if (is_armv7m(armv7m_target)) {
        if ((armv7m_target->fp_feature == FPV4_SP) || (armv7m_target->fp_feature == FPV5_SP) ||
                (armv7m_target->fp_feature == FPV5_DP)) {
            /* Found ARM v7m target which includes a FPU */
            uint32_t cpacr;
 
            retval = target_read_u32(rtos->target, FPU_CPACR, &cpacr);
            if (retval != ERROR_OK) {
                LOG_ERROR("Could not read CPACR register to check FPU state");
                return -1;
            }
 
            /* Check if CP10 and CP11 are set to full access. */
            if (cpacr & 0x00F00000) {
                /* Found target with enabled FPU */
                cm4_fpu_enabled = 1;
            }
        }
    }
 
    if (cm4_fpu_enabled == 1) {
        /* Read the LR to decide between stacking with or without FPU */
        uint32_t lr_svc = 0;
        retval = target_read_u32(rtos->target,
                stack_ptr + 0x20,
                &lr_svc);
        if (retval != ERROR_OK) {
            LOG_OUTPUT("Error reading stack frame from FreeRTOS thread");
            return retval;
        }
        if ((lr_svc & 0x10) == 0)
            return rtos_generic_stack_read(rtos->target, param->stacking_info_cm4f_fpu, stack_ptr, reg_list, num_regs);
        else
            return rtos_generic_stack_read(rtos->target, param->stacking_info_cm4f, stack_ptr, reg_list, num_regs);
    } else
        return rtos_generic_stack_read(rtos->target, param->stacking_info_cm3, stack_ptr, reg_list, num_regs);
}
 
static int freertos_get_symbol_list_to_lookup(struct symbol_table_elem *symbol_list[])
{
    unsigned int i;
    *symbol_list = calloc(
            ARRAY_SIZE(freertos_symbol_list), sizeof(struct symbol_table_elem));
 
    for (i = 0; i < ARRAY_SIZE(freertos_symbol_list); i++) {
        (*symbol_list)[i].symbol_name = freertos_symbol_list[i].name;
        (*symbol_list)[i].optional = freertos_symbol_list[i].optional;
    }
 
    return 0;
}
 
#if 0
 
static int freertos_set_current_thread(struct rtos *rtos, threadid_t thread_id)
{
    return 0;
}
 
static int freertos_get_thread_ascii_info(struct rtos *rtos, threadid_t thread_id, char **info)
{
    int retval;
    const struct freertos_params *param;
 
    if (!rtos)
        return -1;
 
    if (thread_id == 0)
        return -2;
 
    if (!rtos->rtos_specific_params)
        return -3;
 
    param = (const struct freertos_params *) rtos->rtos_specific_params;
 
#define FREERTOS_THREAD_NAME_STR_SIZE (200)
    char tmp_str[FREERTOS_THREAD_NAME_STR_SIZE];
 
    /* Read the thread name */
    retval = target_read_buffer(rtos->target,
            thread_id + param->thread_name_offset,
            FREERTOS_THREAD_NAME_STR_SIZE,
            (uint8_t *)&tmp_str);
    if (retval != ERROR_OK) {
        LOG_ERROR("Error reading first thread item location in FreeRTOS thread list");
        return retval;
    }
    tmp_str[FREERTOS_THREAD_NAME_STR_SIZE-1] = '\x00';
 
    if (tmp_str[0] == '\x00')
        strcpy(tmp_str, "No Name");
 
    *info = malloc(strlen(tmp_str)+1);
    strcpy(*info, tmp_str);
    return 0;
}
 
#endif
 
static bool freertos_detect_rtos(struct target *target)
{
    if ((target->rtos->symbols) &&
            (target->rtos->symbols[FREERTOS_VAL_PX_READY_TASKS_LISTS].address != 0)) {
        /* looks like FreeRTOS */
        return true;
    }
    return false;
}
 
static int freertos_create(struct target *target)
{
    for (unsigned int i = 0; i < ARRAY_SIZE(freertos_params_list); i++)
        if (strcmp(freertos_params_list[i].target_name, target_type_name(target)) == 0) {
            target->rtos->rtos_specific_params = (void *)&freertos_params_list[i];
            return 0;
        }
 
    LOG_ERROR("Could not find target in FreeRTOS compatibility list");
    return -1;
}