hla_target.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2011 by Mathias Kuester                                 *
 *   Mathias Kuester <kesmtp@freenet.de>                                   *
 *                                                                         *
 *   Copyright (C) 2011 by Spencer Oliver                                  *
 *   spen@spen-soft.co.uk                                                  *
 *                                                                         *
 *   revised:  4/25/13 by brent@mbari.org [DCC target request support]     *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include "jtag/interface.h"
#include "jtag/jtag.h"
#include "jtag/hla/hla_transport.h"
#include "jtag/hla/hla_interface.h"
#include "jtag/hla/hla_layout.h"
#include "register.h"
#include "algorithm.h"
#include "target.h"
#include "breakpoints.h"
#include "target_type.h"
#include "armv7m.h"
#include "cortex_m.h"
#include "arm_adi_v5.h"
#include "arm_semihosting.h"
#include "target_request.h"
#include <rtt/rtt.h>
 
#define SAVED_DCRDR  dbgbase  /* FIXME: using target->dbgbase to preserve DCRDR */
 
#define ARMV7M_SCS_DCRSR    DCB_DCRSR
#define ARMV7M_SCS_DCRDR    DCB_DCRDR
 
static inline struct hl_interface *target_to_adapter(struct target *target)
{
    return target->tap->priv;
}
 
static int adapter_load_core_reg_u32(struct target *target,
        uint32_t regsel, uint32_t *value)
{
    struct hl_interface *adapter = target_to_adapter(target);
    return adapter->layout->api->read_reg(adapter->handle, regsel, value);
}
 
static int adapter_store_core_reg_u32(struct target *target,
        uint32_t regsel, uint32_t value)
{
    struct hl_interface *adapter = target_to_adapter(target);
    return adapter->layout->api->write_reg(adapter->handle, regsel, value);
}
 
static int adapter_examine_debug_reason(struct target *target)
{
    if ((target->debug_reason != DBG_REASON_DBGRQ)
            && (target->debug_reason != DBG_REASON_SINGLESTEP)) {
        target->debug_reason = DBG_REASON_BREAKPOINT;
    }
 
    return ERROR_OK;
}
 
static int hl_dcc_read(struct hl_interface *hl_if, uint8_t *value, uint8_t *ctrl)
{
    uint16_t dcrdr;
    int retval = hl_if->layout->api->read_mem(hl_if->handle,
            DCB_DCRDR, 1, sizeof(dcrdr), (uint8_t *)&dcrdr);
    if (retval == ERROR_OK) {
        *ctrl = (uint8_t)dcrdr;
        *value = (uint8_t)(dcrdr >> 8);
 
        LOG_DEBUG("data 0x%x ctrl 0x%x", *value, *ctrl);
 
        if (dcrdr & 1) {
            /* write ack back to software dcc register
             * to signify we have read data */
            /* atomically clear just the byte containing the busy bit */
            static const uint8_t zero;
            retval = hl_if->layout->api->write_mem(hl_if->handle, DCB_DCRDR, 1, 1, &zero);
        }
    }
    return retval;
}
 
static int hl_target_request_data(struct target *target,
    uint32_t size, uint8_t *buffer)
{
    struct hl_interface *hl_if = target_to_adapter(target);
    uint8_t data;
    uint8_t ctrl;
    uint32_t i;
 
    for (i = 0; i < (size * 4); i++) {
        int err = hl_dcc_read(hl_if, &data, &ctrl);
        if (err != ERROR_OK)
            return err;
 
        buffer[i] = data;
    }
 
    return ERROR_OK;
}
 
static int hl_handle_target_request(void *priv)
{
    struct target *target = priv;
    int err;
 
    if (!target_was_examined(target))
        return ERROR_OK;
    struct hl_interface *hl_if = target_to_adapter(target);
 
    if (!target->dbg_msg_enabled)
        return ERROR_OK;
 
    if (target->state == TARGET_RUNNING) {
        uint8_t data;
        uint8_t ctrl;
 
        err = hl_dcc_read(hl_if, &data, &ctrl);
        if (err != ERROR_OK)
            return err;
 
        /* check if we have data */
        if (ctrl & (1 << 0)) {
            uint32_t request;
 
            /* we assume target is quick enough */
            request = data;
            err = hl_dcc_read(hl_if, &data, &ctrl);
            if (err != ERROR_OK)
                return err;
 
            request |= (data << 8);
            err = hl_dcc_read(hl_if, &data, &ctrl);
            if (err != ERROR_OK)
                return err;
 
            request |= (data << 16);
            err = hl_dcc_read(hl_if, &data, &ctrl);
            if (err != ERROR_OK)
                return err;
 
            request |= (data << 24);
            target_request(target, request);
        }
    }
 
    return ERROR_OK;
}
 
static int adapter_init_arch_info(struct target *target,
                       struct cortex_m_common *cortex_m,
                       struct jtag_tap *tap)
{
    struct armv7m_common *armv7m;
 
    LOG_DEBUG("%s", __func__);
 
    armv7m = &cortex_m->armv7m;
    armv7m_init_arch_info(target, armv7m);
 
    armv7m->load_core_reg_u32 = adapter_load_core_reg_u32;
    armv7m->store_core_reg_u32 = adapter_store_core_reg_u32;
 
    armv7m->examine_debug_reason = adapter_examine_debug_reason;
    armv7m->is_hla_target = true;
 
    target_register_timer_callback(hl_handle_target_request, 1,
        TARGET_TIMER_TYPE_PERIODIC, target);
 
    return ERROR_OK;
}
 
static int adapter_init_target(struct command_context *cmd_ctx,
                    struct target *target)
{
    LOG_DEBUG("%s", __func__);
 
    armv7m_build_reg_cache(target);
    arm_semihosting_init(target);
    return ERROR_OK;
}
 
static int adapter_target_create(struct target *target,
        Jim_Interp *interp)
{
    LOG_DEBUG("%s", __func__);
    struct adiv5_private_config *pc = target->private_config;
    if (pc && pc->ap_num != DP_APSEL_INVALID && pc->ap_num != 0) {
        LOG_ERROR("hla_target: invalid parameter -ap-num (> 0)");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    struct cortex_m_common *cortex_m = calloc(1, sizeof(struct cortex_m_common));
    if (!cortex_m) {
        LOG_ERROR("No memory creating target");
        return ERROR_FAIL;
    }
 
    cortex_m->common_magic = CORTEX_M_COMMON_MAGIC;
 
    adapter_init_arch_info(target, cortex_m, target->tap);
 
    return ERROR_OK;
}
 
static int adapter_load_context(struct target *target)
{
    struct armv7m_common *armv7m = target_to_armv7m(target);
    int num_regs = armv7m->arm.core_cache->num_regs;
 
    for (int i = 0; i < num_regs; i++) {
 
        struct reg *r = &armv7m->arm.core_cache->reg_list[i];
        if (r->exist && !r->valid)
            armv7m->arm.read_core_reg(target, r, i, ARM_MODE_ANY);
    }
 
    return ERROR_OK;
}
 
static int adapter_debug_entry(struct target *target)
{
    struct hl_interface *adapter = target_to_adapter(target);
    struct armv7m_common *armv7m = target_to_armv7m(target);
    struct arm *arm = &armv7m->arm;
    struct reg *r;
    uint32_t xpsr;
    int retval;
 
    /* preserve the DCRDR across halts */
    retval = target_read_u32(target, DCB_DCRDR, &target->SAVED_DCRDR);
    if (retval != ERROR_OK)
        return retval;
 
    retval = armv7m->examine_debug_reason(target);
    if (retval != ERROR_OK)
        return retval;
 
    adapter_load_context(target);
 
    /* make sure we clear the vector catch bit */
    adapter->layout->api->write_debug_reg(adapter->handle, DCB_DEMCR, TRCENA);
 
    r = arm->cpsr;
    xpsr = buf_get_u32(r->value, 0, 32);
 
    /* Are we in an exception handler */
    if (xpsr & 0x1FF) {
        armv7m->exception_number = (xpsr & 0x1FF);
 
        arm->core_mode = ARM_MODE_HANDLER;
        arm->map = armv7m_msp_reg_map;
    } else {
        unsigned int control = buf_get_u32(arm->core_cache
                ->reg_list[ARMV7M_CONTROL].value, 0, 3);
 
        /* is this thread privileged? */
        arm->core_mode = control & 1
                ? ARM_MODE_USER_THREAD
                : ARM_MODE_THREAD;
 
        /* which stack is it using? */
        if (control & 2)
            arm->map = armv7m_psp_reg_map;
        else
            arm->map = armv7m_msp_reg_map;
 
        armv7m->exception_number = 0;
    }
 
    LOG_DEBUG("entered debug state in core mode: %s at PC 0x%08" PRIx32 ", target->state: %s",
        arm_mode_name(arm->core_mode),
        buf_get_u32(arm->pc->value, 0, 32),
        target_state_name(target));
 
    return retval;
}
 
static int adapter_poll(struct target *target)
{
    enum target_state state;
    struct hl_interface *adapter = target_to_adapter(target);
    struct armv7m_common *armv7m = target_to_armv7m(target);
    enum target_state prev_target_state = target->state;
 
    state = adapter->layout->api->state(adapter->handle);
 
    if (state == TARGET_UNKNOWN) {
        LOG_ERROR("jtag status contains invalid mode value - communication failure");
        return ERROR_TARGET_FAILURE;
    }
 
    if (prev_target_state == state)
        return ERROR_OK;
 
    if (prev_target_state == TARGET_DEBUG_RUNNING && state == TARGET_RUNNING)
        return ERROR_OK;
 
    target->state = state;
 
    if (state == TARGET_HALTED) {
 
        int retval = adapter_debug_entry(target);
        if (retval != ERROR_OK)
            return retval;
 
        if (prev_target_state == TARGET_DEBUG_RUNNING) {
            target_call_event_callbacks(target, TARGET_EVENT_DEBUG_HALTED);
        } else {
            if (arm_semihosting(target, &retval) != 0)
                return retval;
 
            target_call_event_callbacks(target, TARGET_EVENT_HALTED);
        }
 
        LOG_DEBUG("halted: PC: 0x%08" PRIx32, buf_get_u32(armv7m->arm.pc->value, 0, 32));
    }
 
    return ERROR_OK;
}
 
static int hl_assert_reset(struct target *target)
{
    int res = ERROR_OK;
    struct hl_interface *adapter = target_to_adapter(target);
    struct armv7m_common *armv7m = target_to_armv7m(target);
    bool use_srst_fallback = true;
 
    LOG_DEBUG("%s", __func__);
 
    enum reset_types jtag_reset_config = jtag_get_reset_config();
 
    bool srst_asserted = false;
 
    if ((jtag_reset_config & RESET_HAS_SRST) &&
        (jtag_reset_config & RESET_SRST_NO_GATING)) {
        res = adapter_assert_reset();
        srst_asserted = true;
    }
 
    adapter->layout->api->write_debug_reg(adapter->handle, DCB_DHCSR, DBGKEY|C_DEBUGEN);
 
    if (!target_was_examined(target) && !target->defer_examine
        && srst_asserted && res == ERROR_OK) {
        /* If the target is not examined, now under reset it is good time to retry examination */
        LOG_TARGET_DEBUG(target, "Trying to re-examine under reset");
        target_examine_one(target);
    }
 
    /* only set vector catch if halt is requested */
    if (target->reset_halt)
        adapter->layout->api->write_debug_reg(adapter->handle, DCB_DEMCR, TRCENA|VC_CORERESET);
    else
        adapter->layout->api->write_debug_reg(adapter->handle, DCB_DEMCR, TRCENA);
 
    if (jtag_reset_config & RESET_HAS_SRST) {
        if (!srst_asserted) {
            res = adapter_assert_reset();
        }
        if (res == ERROR_COMMAND_NOTFOUND)
            LOG_ERROR("Hardware srst not supported, falling back to software reset");
        else if (res == ERROR_OK) {
            /* hardware srst supported */
            use_srst_fallback = false;
        }
    }
 
    if (use_srst_fallback) {
        /* stlink v1 api does not support hardware srst, so we use a software reset fallback */
        adapter->layout->api->write_debug_reg(adapter->handle, NVIC_AIRCR, AIRCR_VECTKEY | AIRCR_SYSRESETREQ);
    }
 
    res = adapter->layout->api->reset(adapter->handle);
 
    if (res != ERROR_OK)
        return res;
 
    /* registers are now invalid */
    register_cache_invalidate(armv7m->arm.core_cache);
 
    if (target->reset_halt) {
        target->state = TARGET_RESET;
        target->debug_reason = DBG_REASON_DBGRQ;
    } else {
        target->state = TARGET_HALTED;
    }
 
    return ERROR_OK;
}
 
static int hl_deassert_reset(struct target *target)
{
    enum reset_types jtag_reset_config = jtag_get_reset_config();
 
    LOG_DEBUG("%s", __func__);
 
    if (jtag_reset_config & RESET_HAS_SRST)
        adapter_deassert_reset();
 
    target->SAVED_DCRDR = 0;  /* clear both DCC busy bits on initial resume */
 
    return target->reset_halt ? ERROR_OK : target_resume(target, 1, 0, 0, 0);
}
 
static int adapter_halt(struct target *target)
{
    int res;
    struct hl_interface *adapter = target_to_adapter(target);
 
    LOG_DEBUG("%s", __func__);
 
    if (target->state == TARGET_HALTED) {
        LOG_DEBUG("target was already halted");
        return ERROR_OK;
    }
 
    if (target->state == TARGET_UNKNOWN)
        LOG_WARNING("target was in unknown state when halt was requested");
 
    res = adapter->layout->api->halt(adapter->handle);
 
    if (res != ERROR_OK)
        return res;
 
    target->debug_reason = DBG_REASON_DBGRQ;
 
    return ERROR_OK;
}
 
static int adapter_resume(struct target *target, int current,
        target_addr_t address, int handle_breakpoints,
        int debug_execution)
{
    int res;
    struct hl_interface *adapter = target_to_adapter(target);
    struct armv7m_common *armv7m = target_to_armv7m(target);
    uint32_t resume_pc;
    struct breakpoint *breakpoint = NULL;
    struct reg *pc;
 
    LOG_DEBUG("%s %d " TARGET_ADDR_FMT " %d %d", __func__, current,
            address, handle_breakpoints, debug_execution);
 
    if (target->state != TARGET_HALTED) {
        LOG_TARGET_ERROR(target, "not halted");
        return ERROR_TARGET_NOT_HALTED;
    }
 
    if (!debug_execution) {
        target_free_all_working_areas(target);
        cortex_m_enable_breakpoints(target);
        cortex_m_enable_watchpoints(target);
    }
 
    pc = armv7m->arm.pc;
    if (!current) {
        buf_set_u32(pc->value, 0, 32, address);
        pc->dirty = true;
        pc->valid = true;
    }
 
    if (!breakpoint_find(target, buf_get_u32(pc->value, 0, 32))
            && !debug_execution) {
        armv7m_maybe_skip_bkpt_inst(target, NULL);
    }
 
    resume_pc = buf_get_u32(pc->value, 0, 32);
 
    /* write any user vector flags */
    res = target_write_u32(target, DCB_DEMCR, TRCENA | armv7m->demcr);
    if (res != ERROR_OK)
        return res;
 
    armv7m_restore_context(target);
 
    /* restore SAVED_DCRDR */
    res = target_write_u32(target, DCB_DCRDR, target->SAVED_DCRDR);
    if (res != ERROR_OK)
        return res;
 
    /* registers are now invalid */
    register_cache_invalidate(armv7m->arm.core_cache);
 
    /* the front-end may request us not to handle breakpoints */
    if (handle_breakpoints) {
        /* Single step past breakpoint at current address */
        breakpoint = breakpoint_find(target, resume_pc);
        if (breakpoint) {
            LOG_DEBUG("unset breakpoint at " TARGET_ADDR_FMT " (ID: %" PRIu32 ")",
                    breakpoint->address,
                    breakpoint->unique_id);
            cortex_m_unset_breakpoint(target, breakpoint);
 
            res = adapter->layout->api->step(adapter->handle);
 
            if (res != ERROR_OK)
                return res;
 
            cortex_m_set_breakpoint(target, breakpoint);
        }
    }
 
    res = adapter->layout->api->run(adapter->handle);
 
    if (res != ERROR_OK)
        return res;
 
    target->debug_reason = DBG_REASON_NOTHALTED;
 
    if (!debug_execution) {
        target->state = TARGET_RUNNING;
        target_call_event_callbacks(target, TARGET_EVENT_RESUMED);
    } else {
        target->state = TARGET_DEBUG_RUNNING;
        target_call_event_callbacks(target, TARGET_EVENT_DEBUG_RESUMED);
    }
 
    return ERROR_OK;
}
 
static int adapter_step(struct target *target, int current,
        target_addr_t address, int handle_breakpoints)
{
    int res;
    struct hl_interface *adapter = target_to_adapter(target);
    struct armv7m_common *armv7m = target_to_armv7m(target);
    struct breakpoint *breakpoint = NULL;
    struct reg *pc = armv7m->arm.pc;
    bool bkpt_inst_found = false;
 
    LOG_DEBUG("%s", __func__);
 
    if (target->state != TARGET_HALTED) {
        LOG_TARGET_ERROR(target, "not halted");
        return ERROR_TARGET_NOT_HALTED;
    }
 
    if (!current) {
        buf_set_u32(pc->value, 0, 32, address);
        pc->dirty = true;
        pc->valid = true;
    }
 
    uint32_t pc_value = buf_get_u32(pc->value, 0, 32);
 
    /* the front-end may request us not to handle breakpoints */
    if (handle_breakpoints) {
        breakpoint = breakpoint_find(target, pc_value);
        if (breakpoint)
            cortex_m_unset_breakpoint(target, breakpoint);
    }
 
    armv7m_maybe_skip_bkpt_inst(target, &bkpt_inst_found);
 
    target->debug_reason = DBG_REASON_SINGLESTEP;
 
    armv7m_restore_context(target);
 
    /* restore SAVED_DCRDR */
    res = target_write_u32(target, DCB_DCRDR, target->SAVED_DCRDR);
    if (res != ERROR_OK)
        return res;
 
    target_call_event_callbacks(target, TARGET_EVENT_RESUMED);
 
    res = adapter->layout->api->step(adapter->handle);
 
    if (res != ERROR_OK)
        return res;
 
    /* registers are now invalid */
    register_cache_invalidate(armv7m->arm.core_cache);
 
    if (breakpoint)
        cortex_m_set_breakpoint(target, breakpoint);
 
    adapter_debug_entry(target);
    target_call_event_callbacks(target, TARGET_EVENT_HALTED);
 
    LOG_INFO("halted: PC: 0x%08" PRIx32, buf_get_u32(armv7m->arm.pc->value, 0, 32));
 
    return ERROR_OK;
}
 
static int adapter_read_memory(struct target *target, target_addr_t address,
        uint32_t size, uint32_t count,
        uint8_t *buffer)
{
    struct hl_interface *adapter = target_to_adapter(target);
 
    if (!count || !buffer)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    LOG_DEBUG("%s " TARGET_ADDR_FMT " %" PRIu32 " %" PRIu32,
              __func__, address, size, count);
 
    return adapter->layout->api->read_mem(adapter->handle, address, size, count, buffer);
}
 
static int adapter_write_memory(struct target *target, target_addr_t address,
        uint32_t size, uint32_t count,
        const uint8_t *buffer)
{
    struct hl_interface *adapter = target_to_adapter(target);
 
    if (!count || !buffer)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    LOG_DEBUG("%s " TARGET_ADDR_FMT " %" PRIu32 " %" PRIu32,
              __func__, address, size, count);
 
    return adapter->layout->api->write_mem(adapter->handle, address, size, count, buffer);
}
 
static const struct command_registration hla_command_handlers[] = {
    {
        .chain = arm_command_handlers,
    },
    {
        .chain = armv7m_trace_command_handlers,
    },
    {
        .chain = rtt_target_command_handlers,
    },
    /* START_DEPRECATED_TPIU */
    {
        .chain = arm_tpiu_deprecated_command_handlers,
    },
    /* END_DEPRECATED_TPIU */
    COMMAND_REGISTRATION_DONE
};
 
struct target_type hla_target = {
    .name = "hla_target",
 
    .init_target = adapter_init_target,
    .deinit_target = cortex_m_deinit_target,
    .target_create = adapter_target_create,
    .target_jim_configure = adiv5_jim_configure,
    .examine = cortex_m_examine,
    .commands = hla_command_handlers,
 
    .poll = adapter_poll,
    .arch_state = armv7m_arch_state,
 
    .target_request_data = hl_target_request_data,
    .assert_reset = hl_assert_reset,
    .deassert_reset = hl_deassert_reset,
 
    .halt = adapter_halt,
    .resume = adapter_resume,
    .step = adapter_step,
 
    .get_gdb_arch = arm_get_gdb_arch,
    .get_gdb_reg_list = armv7m_get_gdb_reg_list,
 
    .read_memory = adapter_read_memory,
    .write_memory = adapter_write_memory,
    .checksum_memory = armv7m_checksum_memory,
    .blank_check_memory = armv7m_blank_check_memory,
 
    .run_algorithm = armv7m_run_algorithm,
    .start_algorithm = armv7m_start_algorithm,
    .wait_algorithm = armv7m_wait_algorithm,
 
    .add_breakpoint = cortex_m_add_breakpoint,
    .remove_breakpoint = cortex_m_remove_breakpoint,
    .add_watchpoint = cortex_m_add_watchpoint,
    .remove_watchpoint = cortex_m_remove_watchpoint,
    .profiling = cortex_m_profiling,
};