etm.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2005 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 ***************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include "arm.h"
#include "etm.h"
#include "etb.h"
#include "image.h"
#include "arm_disassembler.h"
#include "register.h"
#include "etm_dummy.h"
 
/*
 * ARM "Embedded Trace Macrocell" (ETM) support -- direct JTAG access.
 *
 * ETM modules collect instruction and/or data trace information, compress
 * it, and transfer it to a debugging host through either a (buffered) trace
 * port (often a 38-pin Mictor connector) or an Embedded Trace Buffer (ETB).
 *
 * There are several generations of these modules.  Original versions have
 * JTAG access through a dedicated scan chain.  Recent versions have added
 * access via coprocessor instructions, memory addressing, and the ARM Debug
 * Interface v5 (ADIv5); and phased out direct JTAG access.
 *
 * This code supports up to the ETMv1.3 architecture, as seen in ETM9 and
 * most common ARM9 systems.  Note: "CoreSight ETM9" implements ETMv3.2,
 * implying non-JTAG connectivity options.
 *
 * Relevant documentation includes:
 *  ARM DDI 0157G ... ETM9 (r2p2) Technical Reference Manual
 *  ARM DDI 0315B ... CoreSight ETM9 (r0p1) Technical Reference Manual
 *  ARM IHI 0014O ... Embedded Trace Macrocell, Architecture Specification
 */
 
enum {
    RO,             /* read/only */
    WO,             /* write/only */
    RW,             /* read/write */
};
 
struct etm_reg_info {
    uint8_t addr;
    uint8_t size;           /* low-N of 32 bits */
    uint8_t mode;           /* RO, WO, RW */
    uint8_t bcd_vers;       /* 1.0, 2.0, etc */
    const char *name;
};
 
/*
 * Registers 0..0x7f are JTAG-addressable using scanchain 6.
 * (Or on some processors, through coprocessor operations.)
 * Newer versions of ETM make some W/O registers R/W, and
 * provide definitions for some previously-unused bits.
 */
 
/* core registers used to version/configure the ETM */
static const struct etm_reg_info etm_core[] = {
    /* NOTE: we "know" the order here ... */
    { ETM_CONFIG, 32, RO, 0x10, "ETM_config", },
    { ETM_ID, 32, RO, 0x20, "ETM_id", },
};
 
/* basic registers that are always there given the right ETM version */
static const struct etm_reg_info etm_basic[] = {
    /* ETM Trace Registers */
    { ETM_CTRL, 32, RW, 0x10, "ETM_ctrl", },
    { ETM_TRIG_EVENT, 17, WO, 0x10, "ETM_trig_event", },
    { ETM_ASIC_CTRL,  8, WO, 0x10, "ETM_asic_ctrl", },
    { ETM_STATUS,  3, RO, 0x11, "ETM_status", },
    { ETM_SYS_CONFIG,  9, RO, 0x12, "ETM_sys_config", },
 
    /* TraceEnable configuration */
    { ETM_TRACE_RESOURCE_CTRL, 32, WO, 0x12, "ETM_trace_resource_ctrl", },
    { ETM_TRACE_EN_CTRL2, 16, WO, 0x12, "ETM_trace_en_ctrl2", },
    { ETM_TRACE_EN_EVENT, 17, WO, 0x10, "ETM_trace_en_event", },
    { ETM_TRACE_EN_CTRL1, 26, WO, 0x10, "ETM_trace_en_ctrl1", },
 
    /* ViewData configuration (data trace) */
    { ETM_VIEWDATA_EVENT, 17, WO, 0x10, "ETM_viewdata_event", },
    { ETM_VIEWDATA_CTRL1, 32, WO, 0x10, "ETM_viewdata_ctrl1", },
    { ETM_VIEWDATA_CTRL2, 32, WO, 0x10, "ETM_viewdata_ctrl2", },
    { ETM_VIEWDATA_CTRL3, 17, WO, 0x10, "ETM_viewdata_ctrl3", },
 
    /* REVISIT exclude VIEWDATA_CTRL2 when it's not there */
 
    { 0x78, 12, WO, 0x20, "ETM_sync_freq", },
    { 0x7a, 22, RO, 0x31, "ETM_config_code_ext", },
    { 0x7b, 32, WO, 0x31, "ETM_ext_input_select", },
    { 0x7c, 32, WO, 0x34, "ETM_trace_start_stop", },
    { 0x7d, 8, WO, 0x34, "ETM_behavior_control", },
};
 
static const struct etm_reg_info etm_fifofull[] = {
    /* FIFOFULL configuration */
    { ETM_FIFOFULL_REGION, 25, WO, 0x10, "ETM_fifofull_region", },
    { ETM_FIFOFULL_LEVEL,  8, WO, 0x10, "ETM_fifofull_level", },
};
 
static const struct etm_reg_info etm_addr_comp[] = {
    /* Address comparator register pairs */
#define ADDR_COMPARATOR(i) \
        { ETM_ADDR_COMPARATOR_VALUE + (i) - 1, 32, WO, 0x10, \
                "ETM_addr_" #i "_comparator_value", }, \
        { ETM_ADDR_ACCESS_TYPE + (i) - 1,  7, WO, 0x10, \
                "ETM_addr_" #i "_access_type", }
    ADDR_COMPARATOR(1),
    ADDR_COMPARATOR(2),
    ADDR_COMPARATOR(3),
    ADDR_COMPARATOR(4),
    ADDR_COMPARATOR(5),
    ADDR_COMPARATOR(6),
    ADDR_COMPARATOR(7),
    ADDR_COMPARATOR(8),
 
    ADDR_COMPARATOR(9),
    ADDR_COMPARATOR(10),
    ADDR_COMPARATOR(11),
    ADDR_COMPARATOR(12),
    ADDR_COMPARATOR(13),
    ADDR_COMPARATOR(14),
    ADDR_COMPARATOR(15),
    ADDR_COMPARATOR(16),
    { 0, 0, 0, 0, NULL }
#undef ADDR_COMPARATOR
};
 
static const struct etm_reg_info etm_data_comp[] = {
    /* Data Value Comparators (NOTE: odd addresses are reserved) */
#define DATA_COMPARATOR(i) \
        { ETM_DATA_COMPARATOR_VALUE + 2*(i) - 1, 32, WO, 0x10, \
                "ETM_data_" #i "_comparator_value", }, \
        { ETM_DATA_COMPARATOR_MASK + 2*(i) - 1, 32, WO, 0x10, \
                "ETM_data_" #i "_comparator_mask", }
    DATA_COMPARATOR(1),
    DATA_COMPARATOR(2),
    DATA_COMPARATOR(3),
    DATA_COMPARATOR(4),
    DATA_COMPARATOR(5),
    DATA_COMPARATOR(6),
    DATA_COMPARATOR(7),
    DATA_COMPARATOR(8),
    { 0, 0, 0, 0, NULL }
#undef DATA_COMPARATOR
};
 
static const struct etm_reg_info etm_counters[] = {
#define ETM_COUNTER(i) \
        { ETM_COUNTER_RELOAD_VALUE + (i) - 1, 16, WO, 0x10, \
                "ETM_counter_" #i "_reload_value", }, \
        { ETM_COUNTER_ENABLE + (i) - 1, 18, WO, 0x10, \
                "ETM_counter_" #i "_enable", }, \
        { ETM_COUNTER_RELOAD_EVENT + (i) - 1, 17, WO, 0x10, \
                "ETM_counter_" #i "_reload_event", }, \
        { ETM_COUNTER_VALUE + (i) - 1, 16, RO, 0x10, \
                "ETM_counter_" #i "_value", }
    ETM_COUNTER(1),
    ETM_COUNTER(2),
    ETM_COUNTER(3),
    ETM_COUNTER(4),
    { 0, 0, 0, 0, NULL }
#undef ETM_COUNTER
};
 
static const struct etm_reg_info etm_sequencer[] = {
#define ETM_SEQ(i) \
        { ETM_SEQUENCER_EVENT + (i), 17, WO, 0x10, \
                "ETM_sequencer_event" #i, }
    ETM_SEQ(0),             /* 1->2 */
    ETM_SEQ(1),             /* 2->1 */
    ETM_SEQ(2),             /* 2->3 */
    ETM_SEQ(3),             /* 3->1 */
    ETM_SEQ(4),             /* 3->2 */
    ETM_SEQ(5),             /* 1->3 */
#undef ETM_SEQ
    /* 0x66 reserved */
    { ETM_SEQUENCER_STATE,  2, RO, 0x10, "ETM_sequencer_state", },
};
 
static const struct etm_reg_info etm_outputs[] = {
#define ETM_OUTPUT(i) \
        { ETM_EXTERNAL_OUTPUT + (i) - 1, 17, WO, 0x10, \
                "ETM_external_output" #i, }
 
    ETM_OUTPUT(1),
    ETM_OUTPUT(2),
    ETM_OUTPUT(3),
    ETM_OUTPUT(4),
    { 0, 0, 0, 0, NULL }
#undef ETM_OUTPUT
};
 
#if 0
    /* registers from 0x6c..0x7f were added after ETMv1.3 */
 
    /* Context ID Comparators */
    { 0x6c, 32, RO, 0x20, "ETM_contextid_comparator_value1", }
    { 0x6d, 32, RO, 0x20, "ETM_contextid_comparator_value2", }
    { 0x6e, 32, RO, 0x20, "ETM_contextid_comparator_value3", }
    { 0x6f, 32, RO, 0x20, "ETM_contextid_comparator_mask", }
#endif
 
static int etm_get_reg(struct reg *reg);
static int etm_read_reg_w_check(struct reg *reg,
    uint8_t *check_value, uint8_t *check_mask);
static int etm_register_user_commands(struct command_context *cmd_ctx);
static int etm_set_reg_w_exec(struct reg *reg, uint8_t *buf);
static int etm_write_reg(struct reg *reg, uint32_t value);
 
static const struct reg_arch_type etm_scan6_type = {
    .get = etm_get_reg,
    .set = etm_set_reg_w_exec,
};
 
/* Look up register by ID ... most ETM instances only
 * support a subset of the possible registers.
 */
static struct reg *etm_reg_lookup(struct etm_context *etm_ctx, unsigned id)
{
    struct reg_cache *cache = etm_ctx->reg_cache;
    unsigned i;
 
    for (i = 0; i < cache->num_regs; i++) {
        struct etm_reg *reg = cache->reg_list[i].arch_info;
 
        if (reg->reg_info->addr == id)
            return &cache->reg_list[i];
    }
 
    /* caller asking for nonexistent register is a bug!
     * REVISIT say which of the N targets was involved */
    LOG_ERROR("ETM: register 0x%02x not available", id);
    return NULL;
}
 
static void etm_reg_add(unsigned bcd_vers, struct arm_jtag *jtag_info,
    struct reg_cache *cache, struct etm_reg *ereg,
    const struct etm_reg_info *r, unsigned nreg)
{
    struct reg *reg = cache->reg_list;
 
    reg += cache->num_regs;
    ereg += cache->num_regs;
 
    /* add up to "nreg" registers from "r", if supported by this
     * version of the ETM, to the specified cache.
     */
    for (; nreg--; r++) {
        /* No more registers to add */
        if (!r->size) {
            LOG_ERROR("etm_reg_add is requested to add non-existing registers, ETM config might be bogus");
            return;
        }
 
        /* this ETM may be too old to have some registers */
        if (r->bcd_vers > bcd_vers)
            continue;
 
        reg->name = r->name;
        reg->size = r->size;
        reg->value = ereg->value;
        reg->arch_info = ereg;
        reg->type = &etm_scan6_type;
        reg++;
        cache->num_regs++;
 
        ereg->reg_info = r;
        ereg->jtag_info = jtag_info;
        ereg++;
    }
}
 
struct reg_cache *etm_build_reg_cache(struct target *target,
    struct arm_jtag *jtag_info, struct etm_context *etm_ctx)
{
    struct reg_cache *reg_cache = malloc(sizeof(struct reg_cache));
    struct reg *reg_list = NULL;
    struct etm_reg *arch_info = NULL;
    unsigned bcd_vers, config;
 
    /* the actual registers are kept in two arrays */
    reg_list = calloc(128, sizeof(struct reg));
    arch_info = calloc(128, sizeof(struct etm_reg));
 
    if (!reg_cache || !reg_list || !arch_info) {
        LOG_ERROR("No memory");
        goto fail;
    }
 
    /* fill in values for the reg cache */
    reg_cache->name = "etm registers";
    reg_cache->next = NULL;
    reg_cache->reg_list = reg_list;
    reg_cache->num_regs = 0;
 
    /* add ETM_CONFIG, then parse its values to see
     * which other registers exist in this ETM
     */
    etm_reg_add(0x10, jtag_info, reg_cache, arch_info,
        etm_core, 1);
 
    etm_get_reg(reg_list);
    etm_ctx->config = buf_get_u32(arch_info->value, 0, 32);
    config = etm_ctx->config;
 
    /* figure ETM version then add base registers */
    if (config & (1 << 31)) {
        LOG_WARNING("ETMv2+ support is incomplete");
 
        /* REVISIT more registers may exist; they may now be
         * readable; more register bits have defined meanings;
         * don't presume trace start/stop support is present;
         * and include any context ID comparator registers.
         */
        etm_reg_add(0x20, jtag_info, reg_cache, arch_info,
            etm_core + 1, 1);
        etm_get_reg(reg_list + 1);
        etm_ctx->id = buf_get_u32(
                arch_info[1].value, 0, 32);
        LOG_DEBUG("ETM ID: %08x", (unsigned) etm_ctx->id);
        bcd_vers = 0x10 + (((etm_ctx->id) >> 4) & 0xff);
 
    } else {
        switch (config >> 28) {
            case 7:
            case 5:
            case 3:
                bcd_vers = 0x13;
                break;
            case 4:
            case 2:
                bcd_vers = 0x12;
                break;
            case 1:
                bcd_vers = 0x11;
                break;
            case 0:
                bcd_vers = 0x10;
                break;
            default:
                LOG_WARNING("Bad ETMv1 protocol %d", config >> 28);
                goto fail;
        }
    }
    etm_ctx->bcd_vers = bcd_vers;
    LOG_INFO("ETM v%d.%d", bcd_vers >> 4, bcd_vers & 0xf);
 
    etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
        etm_basic, ARRAY_SIZE(etm_basic));
 
    /* address and data comparators; counters; outputs */
    etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
        etm_addr_comp, 4 * (0x0f & (config >> 0)));
    etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
        etm_data_comp, 2 * (0x0f & (config >> 4)));
    etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
        etm_counters, 4 * (0x07 & (config >> 13)));
    etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
        etm_outputs, (0x07 & (config >> 20)));
 
    /* FIFOFULL presence is optional
     * REVISIT for ETMv1.2 and later, don't bother adding this
     * unless ETM_SYS_CONFIG says it's also *supported* ...
     */
    if (config & (1 << 23))
        etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
            etm_fifofull, ARRAY_SIZE(etm_fifofull));
 
    /* sequencer is optional (for state-dependant triggering) */
    if (config & (1 << 16))
        etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
            etm_sequencer, ARRAY_SIZE(etm_sequencer));
 
    /* REVISIT could realloc and likely save half the memory
     * in the two chunks we allocated...
     */
 
    /* the ETM might have an ETB connected */
    if (strcmp(etm_ctx->capture_driver->name, "etb") == 0) {
        struct etb *etb = etm_ctx->capture_driver_priv;
 
        if (!etb) {
            LOG_ERROR("etb selected as etm capture driver, but no ETB configured");
            goto fail;
        }
 
        reg_cache->next = etb_build_reg_cache(etb);
 
        etb->reg_cache = reg_cache->next;
    }
 
    etm_ctx->reg_cache = reg_cache;
    return reg_cache;
 
fail:
    free(reg_cache);
    free(reg_list);
    free(arch_info);
    return NULL;
}
 
static int etm_read_reg(struct reg *reg)
{
    return etm_read_reg_w_check(reg, NULL, NULL);
}
 
static int etm_store_reg(struct reg *reg)
{
    return etm_write_reg(reg, buf_get_u32(reg->value, 0, reg->size));
}
 
int etm_setup(struct target *target)
{
    int retval;
    uint32_t etm_ctrl_value;
    struct arm *arm = target_to_arm(target);
    struct etm_context *etm_ctx = arm->etm;
    struct reg *etm_ctrl_reg;
 
    etm_ctrl_reg = etm_reg_lookup(etm_ctx, ETM_CTRL);
    if (!etm_ctrl_reg)
        return ERROR_OK;
 
    /* initialize some ETM control register settings */
    etm_get_reg(etm_ctrl_reg);
    etm_ctrl_value = buf_get_u32(etm_ctrl_reg->value, 0, 32);
 
    /* clear the ETM powerdown bit (0) */
    etm_ctrl_value &= ~ETM_CTRL_POWERDOWN;
 
    /* configure port width (21,6:4), mode (13,17:16) and
     * for older modules clocking (13)
     */
    etm_ctrl_value = (etm_ctrl_value
        & ~ETM_PORT_WIDTH_MASK
        & ~ETM_PORT_MODE_MASK
        & ~ETM_CTRL_DBGRQ
        & ~ETM_PORT_CLOCK_MASK)
        | etm_ctx->control;
 
    buf_set_u32(etm_ctrl_reg->value, 0, 32, etm_ctrl_value);
    etm_store_reg(etm_ctrl_reg);
 
    etm_ctx->control = etm_ctrl_value;
 
    retval = jtag_execute_queue();
    if (retval != ERROR_OK)
        return retval;
 
    /* REVISIT for ETMv3.0 and later, read ETM_sys_config to
     * verify that those width and mode settings are OK ...
     */
 
    retval = etm_ctx->capture_driver->init(etm_ctx);
    if (retval != ERROR_OK) {
        LOG_ERROR("ETM capture driver initialization failed");
        return retval;
    }
    return ERROR_OK;
}
 
static int etm_get_reg(struct reg *reg)
{
    int retval;
 
    retval = etm_read_reg(reg);
    if (retval != ERROR_OK) {
        LOG_ERROR("BUG: error scheduling etm register read");
        return retval;
    }
 
    retval = jtag_execute_queue();
    if (retval != ERROR_OK) {
        LOG_ERROR("register read failed");
        return retval;
    }
 
    return ERROR_OK;
}
 
static int etm_read_reg_w_check(struct reg *reg,
    uint8_t *check_value, uint8_t *check_mask)
{
    struct etm_reg *etm_reg = reg->arch_info;
    assert(etm_reg);
    const struct etm_reg_info *r = etm_reg->reg_info;
    uint8_t reg_addr = r->addr & 0x7f;
    struct scan_field fields[3];
    int retval;
 
    if (etm_reg->reg_info->mode == WO) {
        LOG_ERROR("BUG: can't read write-only register %s", r->name);
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    LOG_DEBUG("%s (%u)", r->name, reg_addr);
 
    retval = arm_jtag_scann(etm_reg->jtag_info, 0x6, TAP_IDLE);
    if (retval != ERROR_OK)
        return retval;
    retval = arm_jtag_set_instr(etm_reg->jtag_info->tap,
            etm_reg->jtag_info->intest_instr,
            NULL,
            TAP_IDLE);
    if (retval != ERROR_OK)
        return retval;
 
    fields[0].num_bits = 32;
    fields[0].out_value = reg->value;
    fields[0].in_value = NULL;
    fields[0].check_value = NULL;
    fields[0].check_mask = NULL;
 
    fields[1].num_bits = 7;
    uint8_t temp1 = 0;
    fields[1].out_value = &temp1;
    buf_set_u32(&temp1, 0, 7, reg_addr);
    fields[1].in_value = NULL;
    fields[1].check_value = NULL;
    fields[1].check_mask = NULL;
 
    fields[2].num_bits = 1;
    uint8_t temp2 = 0;
    fields[2].out_value = &temp2;
    buf_set_u32(&temp2, 0, 1, 0);
    fields[2].in_value = NULL;
    fields[2].check_value = NULL;
    fields[2].check_mask = NULL;
 
    jtag_add_dr_scan(etm_reg->jtag_info->tap, 3, fields, TAP_IDLE);
 
    fields[0].in_value = reg->value;
    fields[0].check_value = check_value;
    fields[0].check_mask = check_mask;
 
    jtag_add_dr_scan_check(etm_reg->jtag_info->tap, 3, fields, TAP_IDLE);
 
    return ERROR_OK;
}
 
static int etm_set_reg(struct reg *reg, uint32_t value)
{
    int retval = etm_write_reg(reg, value);
    if (retval != ERROR_OK) {
        LOG_ERROR("BUG: error scheduling etm register write");
        return retval;
    }
 
    buf_set_u32(reg->value, 0, reg->size, value);
    reg->valid = true;
    reg->dirty = false;
 
    return ERROR_OK;
}
 
static int etm_set_reg_w_exec(struct reg *reg, uint8_t *buf)
{
    int retval;
 
    etm_set_reg(reg, buf_get_u32(buf, 0, reg->size));
 
    retval = jtag_execute_queue();
    if (retval != ERROR_OK) {
        LOG_ERROR("register write failed");
        return retval;
    }
    return ERROR_OK;
}
 
static int etm_write_reg(struct reg *reg, uint32_t value)
{
    struct etm_reg *etm_reg = reg->arch_info;
    const struct etm_reg_info *r = etm_reg->reg_info;
    uint8_t reg_addr = r->addr & 0x7f;
    struct scan_field fields[3];
    int retval;
 
    if (etm_reg->reg_info->mode == RO) {
        LOG_ERROR("BUG: can't write read--only register %s", r->name);
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    LOG_DEBUG("%s (%u): 0x%8.8" PRIx32 "", r->name, reg_addr, value);
 
    retval = arm_jtag_scann(etm_reg->jtag_info, 0x6, TAP_IDLE);
    if (retval != ERROR_OK)
        return retval;
    retval = arm_jtag_set_instr(etm_reg->jtag_info->tap,
            etm_reg->jtag_info->intest_instr,
            NULL,
            TAP_IDLE);
    if (retval != ERROR_OK)
        return retval;
 
    fields[0].num_bits = 32;
    uint8_t tmp1[4];
    fields[0].out_value = tmp1;
    buf_set_u32(tmp1, 0, 32, value);
    fields[0].in_value = NULL;
 
    fields[1].num_bits = 7;
    uint8_t tmp2 = 0;
    fields[1].out_value = &tmp2;
    buf_set_u32(&tmp2, 0, 7, reg_addr);
    fields[1].in_value = NULL;
 
    fields[2].num_bits = 1;
    uint8_t tmp3 = 0;
    fields[2].out_value = &tmp3;
    buf_set_u32(&tmp3, 0, 1, 1);
    fields[2].in_value = NULL;
 
    jtag_add_dr_scan(etm_reg->jtag_info->tap, 3, fields, TAP_IDLE);
 
    return ERROR_OK;
}
 
 
/* ETM trace analysis functionality */
 
static struct etm_capture_driver *etm_capture_drivers[] = {
    &etb_capture_driver,
    &etm_dummy_capture_driver,
    NULL
};
 
static int etm_read_instruction(struct etm_context *ctx, struct arm_instruction *instruction)
{
    int section = -1;
    size_t size_read;
    uint32_t opcode;
    int retval;
 
    if (!ctx->image)
        return ERROR_TRACE_IMAGE_UNAVAILABLE;
 
    /* search for the section the current instruction belongs to */
    for (unsigned int i = 0; i < ctx->image->num_sections; i++) {
        if ((ctx->image->sections[i].base_address <= ctx->current_pc) &&
            (ctx->image->sections[i].base_address + ctx->image->sections[i].size >
            ctx->current_pc)) {
            section = i;
            break;
        }
    }
 
    if (section == -1) {
        /* current instruction couldn't be found in the image */
        return ERROR_TRACE_INSTRUCTION_UNAVAILABLE;
    }
 
    if (ctx->core_state == ARM_STATE_ARM) {
        uint8_t buf[4];
        retval = image_read_section(ctx->image, section,
                ctx->current_pc -
                ctx->image->sections[section].base_address,
                4, buf, &size_read);
        if (retval != ERROR_OK) {
            LOG_ERROR("error while reading instruction");
            return ERROR_TRACE_INSTRUCTION_UNAVAILABLE;
        }
        opcode = target_buffer_get_u32(ctx->target, buf);
        arm_evaluate_opcode(opcode, ctx->current_pc, instruction);
    } else if (ctx->core_state == ARM_STATE_THUMB) {
        uint8_t buf[2];
        retval = image_read_section(ctx->image, section,
                ctx->current_pc -
                ctx->image->sections[section].base_address,
                2, buf, &size_read);
        if (retval != ERROR_OK) {
            LOG_ERROR("error while reading instruction");
            return ERROR_TRACE_INSTRUCTION_UNAVAILABLE;
        }
        opcode = target_buffer_get_u16(ctx->target, buf);
        thumb_evaluate_opcode(opcode, ctx->current_pc, instruction);
    } else if (ctx->core_state == ARM_STATE_JAZELLE) {
        LOG_ERROR("BUG: tracing of jazelle code not supported");
        return ERROR_FAIL;
    } else {
        LOG_ERROR("BUG: unknown core state encountered");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int etmv1_next_packet(struct etm_context *ctx, uint8_t *packet, int apo)
{
    while (ctx->data_index < ctx->trace_depth) {
        /* if the caller specified an address packet offset, skip until the
         * we reach the n-th cycle marked with tracesync */
        if (apo > 0) {
            if (ctx->trace_data[ctx->data_index].flags & ETMV1_TRACESYNC_CYCLE)
                apo--;
 
            if (apo > 0) {
                ctx->data_index++;
                ctx->data_half = 0;
            }
            continue;
        }
 
        /* no tracedata output during a TD cycle
         * or in a trigger cycle */
        if ((ctx->trace_data[ctx->data_index].pipestat == STAT_TD)
            || (ctx->trace_data[ctx->data_index].flags & ETMV1_TRIGGER_CYCLE)) {
            ctx->data_index++;
            ctx->data_half = 0;
            continue;
        }
 
        /* FIXME there are more port widths than these... */
        if ((ctx->control & ETM_PORT_WIDTH_MASK) == ETM_PORT_16BIT) {
            if (ctx->data_half == 0) {
                *packet = ctx->trace_data[ctx->data_index].packet & 0xff;
                ctx->data_half = 1;
            } else {
                *packet = (ctx->trace_data[ctx->data_index].packet & 0xff00) >> 8;
                ctx->data_half = 0;
                ctx->data_index++;
            }
        } else if ((ctx->control & ETM_PORT_WIDTH_MASK) == ETM_PORT_8BIT) {
            *packet = ctx->trace_data[ctx->data_index].packet & 0xff;
            ctx->data_index++;
        } else {
            /* on a 4-bit port, a packet will be output during two consecutive cycles */
            if (ctx->data_index > (ctx->trace_depth - 2))
                return -1;
 
            *packet = ctx->trace_data[ctx->data_index].packet & 0xf;
            *packet |= (ctx->trace_data[ctx->data_index + 1].packet & 0xf) << 4;
            ctx->data_index += 2;
        }
 
        return 0;
    }
 
    return -1;
}
 
static int etmv1_branch_address(struct etm_context *ctx)
{
    int retval;
    uint8_t packet;
    int shift = 0;
    int apo;
    uint32_t i;
 
    /* quit analysis if less than two cycles are left in the trace
     * because we can't extract the APO */
    if (ctx->data_index > (ctx->trace_depth - 2))
        return -1;
 
    /* a BE could be output during an APO cycle, skip the current
     * and continue with the new one */
    if (ctx->trace_data[ctx->pipe_index + 1].pipestat & 0x4)
        return 1;
    if (ctx->trace_data[ctx->pipe_index + 2].pipestat & 0x4)
        return 2;
 
    /* address packet offset encoded in the next two cycles' pipestat bits */
    apo = ctx->trace_data[ctx->pipe_index + 1].pipestat & 0x3;
    apo |= (ctx->trace_data[ctx->pipe_index + 2].pipestat & 0x3) << 2;
 
    /* count number of tracesync cycles between current pipe_index and data_index
     * i.e. the number of tracesyncs that data_index already passed by
     * to subtract them from the APO */
    for (i = ctx->pipe_index; i < ctx->data_index; i++) {
        if (ctx->trace_data[ctx->pipe_index + 1].pipestat & ETMV1_TRACESYNC_CYCLE)
            apo--;
    }
 
    /* extract up to four 7-bit packets */
    do {
        retval = etmv1_next_packet(ctx, &packet, (shift == 0) ? apo + 1 : 0);
        if (retval != 0)
            return -1;
        ctx->last_branch &= ~(0x7f << shift);
        ctx->last_branch |= (packet & 0x7f) << shift;
        shift += 7;
    } while ((packet & 0x80) && (shift < 28));
 
    /* one last packet holding 4 bits of the address, plus the branch reason code */
    if ((shift == 28) && (packet & 0x80)) {
        retval = etmv1_next_packet(ctx, &packet, 0);
        if (retval != 0)
            return -1;
        ctx->last_branch &= 0x0fffffff;
        ctx->last_branch |= (packet & 0x0f) << 28;
        ctx->last_branch_reason = (packet & 0x70) >> 4;
        shift += 4;
    } else
        ctx->last_branch_reason = 0;
 
    if (shift == 32)
        ctx->pc_ok = 1;
 
    /* if a full address was output, we might have branched into Jazelle state */
    if ((shift == 32) && (packet & 0x80))
        ctx->core_state = ARM_STATE_JAZELLE;
    else {
        /* if we didn't branch into Jazelle state, the current processor state is
         * encoded in bit 0 of the branch target address */
        if (ctx->last_branch & 0x1) {
            ctx->core_state = ARM_STATE_THUMB;
            ctx->last_branch &= ~0x1;
        } else {
            ctx->core_state = ARM_STATE_ARM;
            ctx->last_branch &= ~0x3;
        }
    }
 
    return 0;
}
 
static int etmv1_data(struct etm_context *ctx, int size, uint32_t *data)
{
    int j;
    uint8_t buf[4];
    int retval;
 
    for (j = 0; j < size; j++) {
        retval = etmv1_next_packet(ctx, &buf[j], 0);
        if (retval != 0)
            return -1;
    }
 
    if (size == 8) {
        LOG_ERROR("TODO: add support for 64-bit values");
        return -1;
    } else if (size == 4)
        *data = target_buffer_get_u32(ctx->target, buf);
    else if (size == 2)
        *data = target_buffer_get_u16(ctx->target, buf);
    else if (size == 1)
        *data = buf[0];
    else
        return -1;
 
    return 0;
}
 
static int etmv1_analyze_trace(struct etm_context *ctx, struct command_invocation *cmd)
{
    int retval;
    struct arm_instruction instruction;
 
    /* read the trace data if it wasn't read already */
    if (ctx->trace_depth == 0)
        ctx->capture_driver->read_trace(ctx);
 
    if (ctx->trace_depth == 0) {
        command_print(cmd, "Trace is empty.");
        return ERROR_OK;
    }
 
    /* start at the beginning of the captured trace */
    ctx->pipe_index = 0;
    ctx->data_index = 0;
    ctx->data_half = 0;
 
    /* neither the PC nor the data pointer are valid */
    ctx->pc_ok = 0;
    ctx->ptr_ok = 0;
 
    while (ctx->pipe_index < ctx->trace_depth) {
        uint8_t pipestat = ctx->trace_data[ctx->pipe_index].pipestat;
        uint32_t next_pc = ctx->current_pc;
        uint32_t old_data_index = ctx->data_index;
        uint32_t old_data_half = ctx->data_half;
        uint32_t old_index = ctx->pipe_index;
        uint32_t last_instruction = ctx->last_instruction;
        uint32_t cycles = 0;
        int current_pc_ok = ctx->pc_ok;
 
        if (ctx->trace_data[ctx->pipe_index].flags & ETMV1_TRIGGER_CYCLE)
            command_print(cmd, "--- trigger ---");
 
        /* instructions execute in IE/D or BE/D cycles */
        if ((pipestat == STAT_IE) || (pipestat == STAT_ID))
            ctx->last_instruction = ctx->pipe_index;
 
        /* if we don't have a valid pc skip until we reach an indirect branch */
        if ((!ctx->pc_ok) && (pipestat != STAT_BE)) {
            ctx->pipe_index++;
            continue;
        }
 
        /* any indirect branch could have interrupted instruction flow
         * - the branch reason code could indicate a trace discontinuity
         * - a branch to the exception vectors indicates an exception
         */
        if ((pipestat == STAT_BE) || (pipestat == STAT_BD)) {
            /* backup current data index, to be able to consume the branch address
             * before examining data address and values
             */
            old_data_index = ctx->data_index;
            old_data_half = ctx->data_half;
 
            ctx->last_instruction = ctx->pipe_index;
 
            retval = etmv1_branch_address(ctx);
            if (retval != 0) {
                /* negative return value from etmv1_branch_address means we ran out of packets,
                 * quit analysing the trace */
                if (retval < 0)
                    break;
 
                /* a positive return values means the current branch was abandoned,
                 * and a new branch was encountered in cycle ctx->pipe_index + retval;
                 */
                LOG_WARNING(
                    "abandoned branch encountered, correctness of analysis uncertain");
                ctx->pipe_index += retval;
                continue;
            }
 
            /* skip over APO cycles */
            ctx->pipe_index += 2;
 
            switch (ctx->last_branch_reason) {
                case 0x0:   /* normal PC change */
                    next_pc = ctx->last_branch;
                    break;
                case 0x1:   /* tracing enabled */
                    command_print(cmd,
                        "--- tracing enabled at 0x%8.8" PRIx32 " ---",
                        ctx->last_branch);
                    ctx->current_pc = ctx->last_branch;
                    ctx->pipe_index++;
                    continue;
                    break;
                case 0x2:   /* trace restarted after FIFO overflow */
                    command_print(cmd,
                        "--- trace restarted after FIFO overflow at 0x%8.8" PRIx32 " ---",
                        ctx->last_branch);
                    ctx->current_pc = ctx->last_branch;
                    ctx->pipe_index++;
                    continue;
                    break;
                case 0x3:   /* exit from debug state */
                    command_print(cmd,
                        "--- exit from debug state at 0x%8.8" PRIx32 " ---",
                        ctx->last_branch);
                    ctx->current_pc = ctx->last_branch;
                    ctx->pipe_index++;
                    continue;
                    break;
                case 0x4:   /* periodic synchronization point */
                    next_pc = ctx->last_branch;
                    /* if we had no valid PC prior to this synchronization point,
                     * we have to move on with the next trace cycle
                     */
                    if (!current_pc_ok) {
                        command_print(cmd,
                            "--- periodic synchronization point at 0x%8.8" PRIx32 " ---",
                            next_pc);
                        ctx->current_pc = next_pc;
                        ctx->pipe_index++;
                        continue;
                    }
                    break;
                default:    /* reserved */
                    LOG_ERROR(
                        "BUG: branch reason code 0x%" PRIx32 " is reserved",
                        ctx->last_branch_reason);
                    return ERROR_FAIL;
            }
 
            /* if we got here the branch was a normal PC change
             * (or a periodic synchronization point, which means the same for that matter)
             * if we didn't acquire a complete PC continue with the next cycle
             */
            if (!ctx->pc_ok)
                continue;
 
            /* indirect branch to the exception vector means an exception occurred */
            if ((ctx->last_branch <= 0x20)
                || ((ctx->last_branch >= 0xffff0000) &&
                (ctx->last_branch <= 0xffff0020))) {
                if ((ctx->last_branch & 0xff) == 0x10)
                    command_print(cmd, "data abort");
                else {
                    command_print(cmd,
                        "exception vector 0x%2.2" PRIx32 "",
                        ctx->last_branch);
                    ctx->current_pc = ctx->last_branch;
                    ctx->pipe_index++;
                    continue;
                }
            }
        }
 
        /* an instruction was executed (or not, depending on the condition flags)
         * retrieve it from the image for displaying */
        if (ctx->pc_ok && (pipestat != STAT_WT) && (pipestat != STAT_TD) &&
            !(((pipestat == STAT_BE) || (pipestat == STAT_BD)) &&
            ((ctx->last_branch_reason != 0x0) && (ctx->last_branch_reason != 0x4)))) {
            retval = etm_read_instruction(ctx, &instruction);
            if (retval != ERROR_OK) {
                /* can't continue tracing with no image available */
                if (retval == ERROR_TRACE_IMAGE_UNAVAILABLE)
                    return retval;
                else if (retval == ERROR_TRACE_INSTRUCTION_UNAVAILABLE) {
                    /* TODO: handle incomplete images
                     * for now we just quit the analysis*/
                    return retval;
                }
            }
 
            cycles = old_index - last_instruction;
        }
 
        if ((pipestat == STAT_ID) || (pipestat == STAT_BD)) {
            uint32_t new_data_index = ctx->data_index;
            uint32_t new_data_half = ctx->data_half;
 
            /* in case of a branch with data, the branch target address was consumed before
             * we temporarily go back to the saved data index */
            if (pipestat == STAT_BD) {
                ctx->data_index = old_data_index;
                ctx->data_half = old_data_half;
            }
 
            if (ctx->control & ETM_CTRL_TRACE_ADDR) {
                uint8_t packet;
                int shift = 0;
 
                do {
                    retval = etmv1_next_packet(ctx, &packet, 0);
                    if (retval != 0)
                        return ERROR_ETM_ANALYSIS_FAILED;
                    ctx->last_ptr &= ~(0x7f << shift);
                    ctx->last_ptr |= (packet & 0x7f) << shift;
                    shift += 7;
                } while ((packet & 0x80) && (shift < 32));
 
                if (shift >= 32)
                    ctx->ptr_ok = 1;
 
                if (ctx->ptr_ok)
                    command_print(cmd,
                        "address: 0x%8.8" PRIx32 "",
                        ctx->last_ptr);
            }
 
            if (ctx->control & ETM_CTRL_TRACE_DATA) {
                if ((instruction.type == ARM_LDM) ||
                    (instruction.type == ARM_STM)) {
                    int i;
                    for (i = 0; i < 16; i++) {
                        if (instruction.info.load_store_multiple.register_list
                            & (1 << i)) {
                            uint32_t data;
                            if (etmv1_data(ctx, 4, &data) != 0)
                                return ERROR_ETM_ANALYSIS_FAILED;
                            command_print(cmd,
                                "data: 0x%8.8" PRIx32 "",
                                data);
                        }
                    }
                } else if ((instruction.type >= ARM_LDR) &&
                    (instruction.type <= ARM_STRH)) {
                    uint32_t data;
                    if (etmv1_data(ctx, arm_access_size(&instruction),
                        &data) != 0)
                        return ERROR_ETM_ANALYSIS_FAILED;
                    command_print(cmd, "data: 0x%8.8" PRIx32 "", data);
                }
            }
 
            /* restore data index after consuming BD address and data */
            if (pipestat == STAT_BD) {
                ctx->data_index = new_data_index;
                ctx->data_half = new_data_half;
            }
        }
 
        /* adjust PC */
        if ((pipestat == STAT_IE) || (pipestat == STAT_ID)) {
            if (((instruction.type == ARM_B) ||
                (instruction.type == ARM_BL) ||
                (instruction.type == ARM_BLX)) &&
                (instruction.info.b_bl_bx_blx.target_address != 0xffffffff))
                next_pc = instruction.info.b_bl_bx_blx.target_address;
            else
                next_pc += (ctx->core_state == ARM_STATE_ARM) ? 4 : 2;
        } else if (pipestat == STAT_IN)
            next_pc += (ctx->core_state == ARM_STATE_ARM) ? 4 : 2;
 
        if ((pipestat != STAT_TD) && (pipestat != STAT_WT)) {
            char cycles_text[32] = "";
 
            /* if the trace was captured with cycle accurate tracing enabled,
             * output the number of cycles since the last executed instruction
             */
            if (ctx->control & ETM_CTRL_CYCLE_ACCURATE) {
                snprintf(cycles_text, 32, " (%i %s)",
                    (int)cycles,
                    (cycles == 1) ? "cycle" : "cycles");
            }
 
            command_print(cmd, "%s%s%s",
                instruction.text,
                (pipestat == STAT_IN) ? " (not executed)" : "",
                cycles_text);
 
            ctx->current_pc = next_pc;
 
            /* packets for an instruction don't start on or before the preceding
             * functional pipestat (i.e. other than WT or TD)
             */
            if (ctx->data_index <= ctx->pipe_index) {
                ctx->data_index = ctx->pipe_index + 1;
                ctx->data_half = 0;
            }
        }
 
        ctx->pipe_index += 1;
    }
 
    return ERROR_OK;
}
 
static COMMAND_HELPER(handle_etm_tracemode_command_update,
    uint32_t *mode)
{
    uint32_t tracemode;
 
    /* what parts of data access are traced? */
    if (strcmp(CMD_ARGV[0], "none") == 0)
        tracemode = 0;
    else if (strcmp(CMD_ARGV[0], "data") == 0)
        tracemode = ETM_CTRL_TRACE_DATA;
    else if (strcmp(CMD_ARGV[0], "address") == 0)
        tracemode = ETM_CTRL_TRACE_ADDR;
    else if (strcmp(CMD_ARGV[0], "all") == 0)
        tracemode = ETM_CTRL_TRACE_DATA | ETM_CTRL_TRACE_ADDR;
    else {
        command_print(CMD, "invalid option '%s'", CMD_ARGV[0]);
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    uint8_t context_id;
    COMMAND_PARSE_NUMBER(u8, CMD_ARGV[1], context_id);
    switch (context_id) {
        case 0:
            tracemode |= ETM_CTRL_CONTEXTID_NONE;
            break;
        case 8:
            tracemode |= ETM_CTRL_CONTEXTID_8;
            break;
        case 16:
            tracemode |= ETM_CTRL_CONTEXTID_16;
            break;
        case 32:
            tracemode |= ETM_CTRL_CONTEXTID_32;
            break;
        default:
            command_print(CMD, "invalid option '%s'", CMD_ARGV[1]);
            return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    bool etmv1_cycle_accurate;
    COMMAND_PARSE_ENABLE(CMD_ARGV[2], etmv1_cycle_accurate);
    if (etmv1_cycle_accurate)
        tracemode |= ETM_CTRL_CYCLE_ACCURATE;
 
    bool etmv1_branch_output;
    COMMAND_PARSE_ENABLE(CMD_ARGV[3], etmv1_branch_output);
    if (etmv1_branch_output)
        tracemode |= ETM_CTRL_BRANCH_OUTPUT;
 
    /* IGNORED:
     *  - CPRT tracing (coprocessor register transfers)
     *  - debug request (causes debug entry on trigger)
     *  - stall on FIFOFULL (preventing tracedata loss)
     */
    *mode = tracemode;
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(handle_etm_tracemode_command)
{
    struct target *target = get_current_target(CMD_CTX);
    struct arm *arm = target_to_arm(target);
    struct etm_context *etm;
 
    if (!is_arm(arm)) {
        command_print(CMD, "ETM: current target isn't an ARM");
        return ERROR_FAIL;
    }
 
    etm = arm->etm;
    if (!etm) {
        command_print(CMD, "current target doesn't have an ETM configured");
        return ERROR_FAIL;
    }
 
    uint32_t tracemode = etm->control;
 
    switch (CMD_ARGC) {
        case 0:
            break;
        case 4:
            CALL_COMMAND_HANDLER(handle_etm_tracemode_command_update,
                &tracemode);
            break;
        default:
            return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    command_print(CMD, "current tracemode configuration:");
 
    switch (tracemode & ETM_CTRL_TRACE_MASK) {
        default:
            command_print(CMD, "data tracing: none");
            break;
        case ETM_CTRL_TRACE_DATA:
            command_print(CMD, "data tracing: data only");
            break;
        case ETM_CTRL_TRACE_ADDR:
            command_print(CMD, "data tracing: address only");
            break;
        case ETM_CTRL_TRACE_DATA | ETM_CTRL_TRACE_ADDR:
            command_print(CMD, "data tracing: address and data");
            break;
    }
 
    switch (tracemode & ETM_CTRL_CONTEXTID_MASK) {
        case ETM_CTRL_CONTEXTID_NONE:
            command_print(CMD, "contextid tracing: none");
            break;
        case ETM_CTRL_CONTEXTID_8:
            command_print(CMD, "contextid tracing: 8 bit");
            break;
        case ETM_CTRL_CONTEXTID_16:
            command_print(CMD, "contextid tracing: 16 bit");
            break;
        case ETM_CTRL_CONTEXTID_32:
            command_print(CMD, "contextid tracing: 32 bit");
            break;
    }
 
    if (tracemode & ETM_CTRL_CYCLE_ACCURATE)
        command_print(CMD, "cycle-accurate tracing enabled");
    else
        command_print(CMD, "cycle-accurate tracing disabled");
 
    if (tracemode & ETM_CTRL_BRANCH_OUTPUT)
        command_print(CMD, "full branch address output enabled");
    else
        command_print(CMD, "full branch address output disabled");
 
#define TRACEMODE_MASK ( \
        ETM_CTRL_CONTEXTID_MASK \
        | ETM_CTRL_BRANCH_OUTPUT \
        | ETM_CTRL_CYCLE_ACCURATE \
        | ETM_CTRL_TRACE_MASK \
        )
 
    /* only update ETM_CTRL register if tracemode changed */
    if ((etm->control & TRACEMODE_MASK) != tracemode) {
        struct reg *etm_ctrl_reg;
 
        etm_ctrl_reg = etm_reg_lookup(etm, ETM_CTRL);
        if (!etm_ctrl_reg)
            return ERROR_FAIL;
 
        etm->control &= ~TRACEMODE_MASK;
        etm->control |= tracemode & TRACEMODE_MASK;
 
        buf_set_u32(etm_ctrl_reg->value, 0, 32, etm->control);
        etm_store_reg(etm_ctrl_reg);
 
        /* invalidate old trace data */
        etm->capture_status = TRACE_IDLE;
        if (etm->trace_depth > 0) {
            free(etm->trace_data);
            etm->trace_data = NULL;
        }
        etm->trace_depth = 0;
    }
 
#undef TRACEMODE_MASK
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(handle_etm_config_command)
{
    struct target *target;
    struct arm *arm;
    uint32_t portmode = 0x0;
    struct etm_context *etm_ctx;
    int i;
 
    if (CMD_ARGC != 5)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    target = get_target(CMD_ARGV[0]);
    if (!target) {
        LOG_ERROR("target '%s' not defined", CMD_ARGV[0]);
        return ERROR_FAIL;
    }
 
    arm = target_to_arm(target);
    if (!is_arm(arm)) {
        command_print(CMD, "target '%s' is '%s'; not an ARM",
            target_name(target),
            target_type_name(target));
        return ERROR_FAIL;
    }
 
    /* FIXME for ETMv3.0 and above -- and we don't yet know what ETM
     * version we'll be using!! -- so we can't know how to validate
     * params yet.  "etm config" should likely be *AFTER* hookup...
     *
     *  - Many more widths might be supported ... and we can easily
     *    check whether our setting "took".
     *
     *  - The "clock" and "mode" bits are interpreted differently.
     *    See ARM IHI 0014O table 2-17 for the old behaviour, and
     *    table 2-18 for the new.  With ETB it's best to specify
     *    "normal full" ...
     */
    uint8_t port_width;
    COMMAND_PARSE_NUMBER(u8, CMD_ARGV[1], port_width);
    switch (port_width) {
        /* before ETMv3.0 */
        case 4:
            portmode |= ETM_PORT_4BIT;
            break;
        case 8:
            portmode |= ETM_PORT_8BIT;
            break;
        case 16:
            portmode |= ETM_PORT_16BIT;
            break;
        /* ETMv3.0 and later*/
        case 24:
            portmode |= ETM_PORT_24BIT;
            break;
        case 32:
            portmode |= ETM_PORT_32BIT;
            break;
        case 48:
            portmode |= ETM_PORT_48BIT;
            break;
        case 64:
            portmode |= ETM_PORT_64BIT;
            break;
        case 1:
            portmode |= ETM_PORT_1BIT;
            break;
        case 2:
            portmode |= ETM_PORT_2BIT;
            break;
        default:
            command_print(CMD,
                "unsupported ETM port width '%s'", CMD_ARGV[1]);
            return ERROR_FAIL;
    }
 
    if (strcmp("normal", CMD_ARGV[2]) == 0)
        portmode |= ETM_PORT_NORMAL;
    else if (strcmp("multiplexed", CMD_ARGV[2]) == 0)
        portmode |= ETM_PORT_MUXED;
    else if (strcmp("demultiplexed", CMD_ARGV[2]) == 0)
        portmode |= ETM_PORT_DEMUXED;
    else {
        command_print(CMD,
            "unsupported ETM port mode '%s', must be 'normal', 'multiplexed' or 'demultiplexed'",
            CMD_ARGV[2]);
        return ERROR_FAIL;
    }
 
    if (strcmp("half", CMD_ARGV[3]) == 0)
        portmode |= ETM_PORT_HALF_CLOCK;
    else if (strcmp("full", CMD_ARGV[3]) == 0)
        portmode |= ETM_PORT_FULL_CLOCK;
    else {
        command_print(CMD,
            "unsupported ETM port clocking '%s', must be 'full' or 'half'",
            CMD_ARGV[3]);
        return ERROR_FAIL;
    }
 
    etm_ctx = calloc(1, sizeof(struct etm_context));
    if (!etm_ctx) {
        LOG_DEBUG("out of memory");
        return ERROR_FAIL;
    }
 
    for (i = 0; etm_capture_drivers[i]; i++) {
        if (strcmp(CMD_ARGV[4], etm_capture_drivers[i]->name) == 0) {
            int retval = register_commands(CMD_CTX, NULL, etm_capture_drivers[i]->commands);
            if (retval != ERROR_OK) {
                free(etm_ctx);
                return retval;
            }
 
            etm_ctx->capture_driver = etm_capture_drivers[i];
 
            break;
        }
    }
 
    if (!etm_capture_drivers[i]) {
        /* no supported capture driver found, don't register an ETM */
        free(etm_ctx);
        LOG_ERROR("trace capture driver '%s' not found", CMD_ARGV[4]);
        return ERROR_FAIL;
    }
 
    etm_ctx->target = target;
    etm_ctx->trace_data = NULL;
    etm_ctx->control = portmode;
    etm_ctx->core_state = ARM_STATE_ARM;
 
    arm->etm = etm_ctx;
 
    return etm_register_user_commands(CMD_CTX);
}
 
COMMAND_HANDLER(handle_etm_info_command)
{
    struct target *target;
    struct arm *arm;
    struct etm_context *etm;
    struct reg *etm_sys_config_reg;
    int max_port_size;
    uint32_t config;
 
    target = get_current_target(CMD_CTX);
    arm = target_to_arm(target);
    if (!is_arm(arm)) {
        command_print(CMD, "ETM: current target isn't an ARM");
        return ERROR_FAIL;
    }
 
    etm = arm->etm;
    if (!etm) {
        command_print(CMD, "current target doesn't have an ETM configured");
        return ERROR_FAIL;
    }
 
    command_print(CMD, "ETM v%d.%d",
        etm->bcd_vers >> 4, etm->bcd_vers & 0xf);
    command_print(CMD, "pairs of address comparators: %i",
        (int) (etm->config >> 0) & 0x0f);
    command_print(CMD, "data comparators: %i",
        (int) (etm->config >> 4) & 0x0f);
    command_print(CMD, "memory map decoders: %i",
        (int) (etm->config >> 8) & 0x1f);
    command_print(CMD, "number of counters: %i",
        (int) (etm->config >> 13) & 0x07);
    command_print(CMD, "sequencer %spresent",
        (int) (etm->config & (1 << 16)) ? "" : "not ");
    command_print(CMD, "number of ext. inputs: %i",
        (int) (etm->config >> 17) & 0x07);
    command_print(CMD, "number of ext. outputs: %i",
        (int) (etm->config >> 20) & 0x07);
    command_print(CMD, "FIFO full %spresent",
        (int) (etm->config & (1 << 23)) ? "" : "not ");
    if (etm->bcd_vers < 0x20)
        command_print(CMD, "protocol version: %i",
            (int) (etm->config >> 28) & 0x07);
    else {
        command_print(CMD,
            "coprocessor and memory access %ssupported",
            (etm->config & (1 << 26)) ? "" : "not ");
        command_print(CMD, "trace start/stop %spresent",
            (etm->config & (1 << 26)) ? "" : "not ");
        command_print(CMD, "number of context comparators: %i",
            (int) (etm->config >> 24) & 0x03);
    }
 
    /* SYS_CONFIG isn't present before ETMv1.2 */
    etm_sys_config_reg = etm_reg_lookup(etm, ETM_SYS_CONFIG);
    if (!etm_sys_config_reg)
        return ERROR_OK;
 
    etm_get_reg(etm_sys_config_reg);
    config = buf_get_u32(etm_sys_config_reg->value, 0, 32);
 
    LOG_DEBUG("ETM SYS CONFIG %08x", (unsigned) config);
 
    max_port_size = config & 0x7;
    if (etm->bcd_vers >= 0x30)
        max_port_size |= (config >> 6) & 0x08;
    switch (max_port_size) {
        /* before ETMv3.0 */
        case 0:
            max_port_size = 4;
            break;
        case 1:
            max_port_size = 8;
            break;
        case 2:
            max_port_size = 16;
            break;
        /* ETMv3.0 and later*/
        case 3:
            max_port_size = 24;
            break;
        case 4:
            max_port_size = 32;
            break;
        case 5:
            max_port_size = 48;
            break;
        case 6:
            max_port_size = 64;
            break;
        case 8:
            max_port_size = 1;
            break;
        case 9:
            max_port_size = 2;
            break;
        default:
            LOG_ERROR("Illegal max_port_size");
            return ERROR_FAIL;
    }
    command_print(CMD, "max. port size: %i", max_port_size);
 
    if (etm->bcd_vers < 0x30) {
        command_print(CMD, "half-rate clocking %ssupported",
            (config & (1 << 3)) ? "" : "not ");
        command_print(CMD, "full-rate clocking %ssupported",
            (config & (1 << 4)) ? "" : "not ");
        command_print(CMD, "normal trace format %ssupported",
            (config & (1 << 5)) ? "" : "not ");
        command_print(CMD, "multiplex trace format %ssupported",
            (config & (1 << 6)) ? "" : "not ");
        command_print(CMD, "demultiplex trace format %ssupported",
            (config & (1 << 7)) ? "" : "not ");
    } else {
        /* REVISIT show which size and format are selected ... */
        command_print(CMD, "current port size %ssupported",
            (config & (1 << 10)) ? "" : "not ");
        command_print(CMD, "current trace format %ssupported",
            (config & (1 << 11)) ? "" : "not ");
    }
    if (etm->bcd_vers >= 0x21)
        command_print(CMD, "fetch comparisons %ssupported",
            (config & (1 << 17)) ? "not " : "");
    command_print(CMD, "FIFO full %ssupported",
        (config & (1 << 8)) ? "" : "not ");
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(handle_etm_status_command)
{
    struct target *target;
    struct arm *arm;
    struct etm_context *etm;
    trace_status_t trace_status;
 
    target = get_current_target(CMD_CTX);
    arm = target_to_arm(target);
    if (!is_arm(arm)) {
        command_print(CMD, "ETM: current target isn't an ARM");
        return ERROR_FAIL;
    }
 
    etm = arm->etm;
    if (!etm) {
        command_print(CMD, "current target doesn't have an ETM configured");
        return ERROR_FAIL;
    }
 
    /* ETM status */
    if (etm->bcd_vers >= 0x11) {
        struct reg *reg;
 
        reg = etm_reg_lookup(etm, ETM_STATUS);
        if (!reg)
            return ERROR_FAIL;
        if (etm_get_reg(reg) == ERROR_OK) {
            unsigned s = buf_get_u32(reg->value, 0, reg->size);
 
            command_print(CMD, "etm: %s%s%s%s",
                /* bit(1) == progbit */
                (etm->bcd_vers >= 0x12)
                ? ((s & (1 << 1))
                ? "disabled" : "enabled")
                : "?",
                ((s & (1 << 3)) && etm->bcd_vers >= 0x31)
                ? " triggered" : "",
                ((s & (1 << 2)) && etm->bcd_vers >= 0x12)
                ? " start/stop" : "",
                ((s & (1 << 0)) && etm->bcd_vers >= 0x11)
                ? " untraced-overflow" : "");
        }   /* else ignore and try showing trace port status */
    }
 
    /* Trace Port Driver status */
    trace_status = etm->capture_driver->status(etm);
    if (trace_status == TRACE_IDLE)
        command_print(CMD, "%s: idle", etm->capture_driver->name);
    else {
        static char *completed = " completed";
        static char *running = " is running";
        static char *overflowed = ", overflowed";
        static char *triggered = ", triggered";
 
        command_print(CMD, "%s: trace collection%s%s%s",
            etm->capture_driver->name,
            (trace_status & TRACE_RUNNING) ? running : completed,
            (trace_status & TRACE_OVERFLOWED) ? overflowed : "",
            (trace_status & TRACE_TRIGGERED) ? triggered : "");
 
        if (etm->trace_depth > 0) {
            command_print(CMD, "%i frames of trace data read",
                (int)(etm->trace_depth));
        }
    }
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(handle_etm_image_command)
{
    struct target *target;
    struct arm *arm;
    struct etm_context *etm_ctx;
 
    if (CMD_ARGC < 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    target = get_current_target(CMD_CTX);
    arm = target_to_arm(target);
    if (!is_arm(arm)) {
        command_print(CMD, "ETM: current target isn't an ARM");
        return ERROR_FAIL;
    }
 
    etm_ctx = arm->etm;
    if (!etm_ctx) {
        command_print(CMD, "current target doesn't have an ETM configured");
        return ERROR_FAIL;
    }
 
    if (etm_ctx->image) {
        image_close(etm_ctx->image);
        free(etm_ctx->image);
        command_print(CMD, "previously loaded image found and closed");
    }
 
    etm_ctx->image = malloc(sizeof(struct image));
    etm_ctx->image->base_address_set = false;
    etm_ctx->image->start_address_set = false;
 
    /* a base address isn't always necessary, default to 0x0 (i.e. don't relocate) */
    if (CMD_ARGC >= 2) {
        etm_ctx->image->base_address_set = true;
        COMMAND_PARSE_NUMBER(llong, CMD_ARGV[1], etm_ctx->image->base_address);
    } else
        etm_ctx->image->base_address_set = false;
 
    if (image_open(etm_ctx->image, CMD_ARGV[0],
        (CMD_ARGC >= 3) ? CMD_ARGV[2] : NULL) != ERROR_OK) {
        free(etm_ctx->image);
        etm_ctx->image = NULL;
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(handle_etm_dump_command)
{
    struct fileio *file;
    struct target *target;
    struct arm *arm;
    struct etm_context *etm_ctx;
    uint32_t i;
 
    if (CMD_ARGC != 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    target = get_current_target(CMD_CTX);
    arm = target_to_arm(target);
    if (!is_arm(arm)) {
        command_print(CMD, "ETM: current target isn't an ARM");
        return ERROR_FAIL;
    }
 
    etm_ctx = arm->etm;
    if (!etm_ctx) {
        command_print(CMD, "current target doesn't have an ETM configured");
        return ERROR_FAIL;
    }
 
    if (etm_ctx->capture_driver->status(etm_ctx) == TRACE_IDLE) {
        command_print(CMD, "trace capture wasn't enabled, no trace data captured");
        return ERROR_OK;
    }
 
    if (etm_ctx->capture_driver->status(etm_ctx) & TRACE_RUNNING) {
        /* TODO: if on-the-fly capture is to be supported, this needs to be changed */
        command_print(CMD, "trace capture not completed");
        return ERROR_FAIL;
    }
 
    /* read the trace data if it wasn't read already */
    if (etm_ctx->trace_depth == 0)
        etm_ctx->capture_driver->read_trace(etm_ctx);
 
    if (fileio_open(&file, CMD_ARGV[0], FILEIO_WRITE, FILEIO_BINARY) != ERROR_OK)
        return ERROR_FAIL;
 
    fileio_write_u32(file, etm_ctx->capture_status);
    fileio_write_u32(file, etm_ctx->control);
    fileio_write_u32(file, etm_ctx->trace_depth);
 
    for (i = 0; i < etm_ctx->trace_depth; i++) {
        fileio_write_u32(file, etm_ctx->trace_data[i].pipestat);
        fileio_write_u32(file, etm_ctx->trace_data[i].packet);
        fileio_write_u32(file, etm_ctx->trace_data[i].flags);
    }
 
    fileio_close(file);
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(handle_etm_load_command)
{
    struct fileio *file;
    struct target *target;
    struct arm *arm;
    struct etm_context *etm_ctx;
    uint32_t i;
 
    if (CMD_ARGC != 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    target = get_current_target(CMD_CTX);
    arm = target_to_arm(target);
    if (!is_arm(arm)) {
        command_print(CMD, "ETM: current target isn't an ARM");
        return ERROR_FAIL;
    }
 
    etm_ctx = arm->etm;
    if (!etm_ctx) {
        command_print(CMD, "current target doesn't have an ETM configured");
        return ERROR_FAIL;
    }
 
    if (etm_ctx->capture_driver->status(etm_ctx) & TRACE_RUNNING) {
        command_print(CMD, "trace capture running, stop first");
        return ERROR_FAIL;
    }
 
    if (fileio_open(&file, CMD_ARGV[0], FILEIO_READ, FILEIO_BINARY) != ERROR_OK)
        return ERROR_FAIL;
 
    size_t filesize;
    int retval = fileio_size(file, &filesize);
    if (retval != ERROR_OK) {
        fileio_close(file);
        return retval;
    }
 
    if (filesize % 4) {
        command_print(CMD, "size isn't a multiple of 4, no valid trace data");
        fileio_close(file);
        return ERROR_FAIL;
    }
 
    if (etm_ctx->trace_depth > 0) {
        free(etm_ctx->trace_data);
        etm_ctx->trace_data = NULL;
    }
 
    {
        uint32_t tmp;
        fileio_read_u32(file, &tmp); etm_ctx->capture_status = tmp;
        fileio_read_u32(file, &tmp); etm_ctx->control = tmp;
        fileio_read_u32(file, &etm_ctx->trace_depth);
    }
    etm_ctx->trace_data = malloc(sizeof(struct etmv1_trace_data) * etm_ctx->trace_depth);
    if (!etm_ctx->trace_data) {
        command_print(CMD, "not enough memory to perform operation");
        fileio_close(file);
        return ERROR_FAIL;
    }
 
    for (i = 0; i < etm_ctx->trace_depth; i++) {
        uint32_t pipestat, packet, flags;
        fileio_read_u32(file, &pipestat);
        fileio_read_u32(file, &packet);
        fileio_read_u32(file, &flags);
        etm_ctx->trace_data[i].pipestat = pipestat & 0xff;
        etm_ctx->trace_data[i].packet = packet & 0xffff;
        etm_ctx->trace_data[i].flags = flags;
    }
 
    fileio_close(file);
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(handle_etm_start_command)
{
    struct target *target;
    struct arm *arm;
    struct etm_context *etm_ctx;
    struct reg *etm_ctrl_reg;
 
    target = get_current_target(CMD_CTX);
    arm = target_to_arm(target);
    if (!is_arm(arm)) {
        command_print(CMD, "ETM: current target isn't an ARM");
        return ERROR_FAIL;
    }
 
    etm_ctx = arm->etm;
    if (!etm_ctx) {
        command_print(CMD, "current target doesn't have an ETM configured");
        return ERROR_FAIL;
    }
 
    /* invalidate old tracing data */
    etm_ctx->capture_status = TRACE_IDLE;
    if (etm_ctx->trace_depth > 0) {
        free(etm_ctx->trace_data);
        etm_ctx->trace_data = NULL;
    }
    etm_ctx->trace_depth = 0;
 
    etm_ctrl_reg = etm_reg_lookup(etm_ctx, ETM_CTRL);
    if (!etm_ctrl_reg)
        return ERROR_FAIL;
 
    etm_get_reg(etm_ctrl_reg);
 
    /* Clear programming bit (10), set port selection bit (11) */
    buf_set_u32(etm_ctrl_reg->value, 10, 2, 0x2);
 
    etm_store_reg(etm_ctrl_reg);
    jtag_execute_queue();
 
    etm_ctx->capture_driver->start_capture(etm_ctx);
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(handle_etm_stop_command)
{
    struct target *target;
    struct arm *arm;
    struct etm_context *etm_ctx;
    struct reg *etm_ctrl_reg;
 
    target = get_current_target(CMD_CTX);
    arm = target_to_arm(target);
    if (!is_arm(arm)) {
        command_print(CMD, "ETM: current target isn't an ARM");
        return ERROR_FAIL;
    }
 
    etm_ctx = arm->etm;
    if (!etm_ctx) {
        command_print(CMD, "current target doesn't have an ETM configured");
        return ERROR_FAIL;
    }
 
    etm_ctrl_reg = etm_reg_lookup(etm_ctx, ETM_CTRL);
    if (!etm_ctrl_reg)
        return ERROR_FAIL;
 
    etm_get_reg(etm_ctrl_reg);
 
    /* Set programming bit (10), clear port selection bit (11) */
    buf_set_u32(etm_ctrl_reg->value, 10, 2, 0x1);
 
    etm_store_reg(etm_ctrl_reg);
    jtag_execute_queue();
 
    etm_ctx->capture_driver->stop_capture(etm_ctx);
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(handle_etm_trigger_debug_command)
{
    struct target *target;
    struct arm *arm;
    struct etm_context *etm;
 
    target = get_current_target(CMD_CTX);
    arm = target_to_arm(target);
    if (!is_arm(arm)) {
        command_print(CMD, "ETM: %s isn't an ARM",
            target_name(target));
        return ERROR_FAIL;
    }
 
    etm = arm->etm;
    if (!etm) {
        command_print(CMD, "ETM: no ETM configured for %s",
            target_name(target));
        return ERROR_FAIL;
    }
 
    if (CMD_ARGC == 1) {
        struct reg *etm_ctrl_reg;
        bool dbgrq;
 
        etm_ctrl_reg = etm_reg_lookup(etm, ETM_CTRL);
        if (!etm_ctrl_reg)
            return ERROR_FAIL;
 
        COMMAND_PARSE_ENABLE(CMD_ARGV[0], dbgrq);
        if (dbgrq)
            etm->control |= ETM_CTRL_DBGRQ;
        else
            etm->control &= ~ETM_CTRL_DBGRQ;
 
        /* etm->control will be written to hardware
         * the next time an "etm start" is issued.
         */
        buf_set_u32(etm_ctrl_reg->value, 0, 32, etm->control);
    }
 
    command_print(CMD, "ETM: %s debug halt",
        (etm->control & ETM_CTRL_DBGRQ)
        ? "triggers"
        : "does not trigger");
    return ERROR_OK;
}
 
COMMAND_HANDLER(handle_etm_analyze_command)
{
    struct target *target;
    struct arm *arm;
    struct etm_context *etm_ctx;
    int retval;
 
    target = get_current_target(CMD_CTX);
    arm = target_to_arm(target);
    if (!is_arm(arm)) {
        command_print(CMD, "ETM: current target isn't an ARM");
        return ERROR_FAIL;
    }
 
    etm_ctx = arm->etm;
    if (!etm_ctx) {
        command_print(CMD, "current target doesn't have an ETM configured");
        return ERROR_FAIL;
    }
 
    retval = etmv1_analyze_trace(etm_ctx, CMD);
    if (retval != ERROR_OK) {
        /* FIX! error should be reported inside etmv1_analyze_trace() */
        switch (retval) {
            case ERROR_ETM_ANALYSIS_FAILED:
                command_print(CMD,
                    "further analysis failed (corrupted trace data or just end of data");
                break;
            case ERROR_TRACE_INSTRUCTION_UNAVAILABLE:
                command_print(CMD,
                    "no instruction for current address available, analysis aborted");
                break;
            case ERROR_TRACE_IMAGE_UNAVAILABLE:
                command_print(CMD, "no image available for trace analysis");
                break;
            default:
                command_print(CMD, "unknown error");
        }
    }
 
    return retval;
}
 
static const struct command_registration etm_config_command_handlers[] = {
    {
        /* NOTE:  with ADIv5, ETMs are accessed by DAP operations,
         * possibly over SWD, not JTAG scanchain 6 of 'target'.
         *
         * Also, these parameters don't match ETM v3+ modules...
         */
        .name = "config",
        .handler = handle_etm_config_command,
        .mode = COMMAND_CONFIG,
        .help = "Set up ETM output port.",
        .usage = "target port_width port_mode clocking capture_driver",
    },
    COMMAND_REGISTRATION_DONE
};
const struct command_registration etm_command_handlers[] = {
    {
        .name = "etm",
        .mode = COMMAND_ANY,
        .help = "Embedded Trace Macrocell command group",
        .usage = "",
        .chain = etm_config_command_handlers,
    },
    COMMAND_REGISTRATION_DONE
};
 
static const struct command_registration etm_exec_command_handlers[] = {
    {
        .name = "tracemode",
        .handler = handle_etm_tracemode_command,
        .mode = COMMAND_EXEC,
        .help = "configure/display trace mode",
        .usage = "('none'|'data'|'address'|'all') "
            "context_id_bits "
            "['enable'|'disable'] "
            "['enable'|'disable']",
    },
    {
        .name = "info",
        .handler = handle_etm_info_command,
        .mode = COMMAND_EXEC,
        .usage = "",
        .help = "display info about the current target's ETM",
    },
    {
        .name = "status",
        .handler = handle_etm_status_command,
        .mode = COMMAND_EXEC,
        .usage = "",
        .help = "display current target's ETM status",
    },
    {
        .name = "start",
        .handler = handle_etm_start_command,
        .mode = COMMAND_EXEC,
        .usage = "",
        .help = "start ETM trace collection",
    },
    {
        .name = "stop",
        .handler = handle_etm_stop_command,
        .mode = COMMAND_EXEC,
        .usage = "",
        .help = "stop ETM trace collection",
    },
    {
        .name = "trigger_debug",
        .handler = handle_etm_trigger_debug_command,
        .mode = COMMAND_EXEC,
        .help = "enable/disable debug entry on trigger",
        .usage = "['enable'|'disable']",
    },
    {
        .name = "analyze",
        .handler = handle_etm_analyze_command,
        .mode = COMMAND_EXEC,
        .usage = "",
        .help = "analyze collected ETM trace",
    },
    {
        .name = "image",
        .handler = handle_etm_image_command,
        .mode = COMMAND_EXEC,
        .help = "load image from file with optional offset",
        .usage = "<file> [base address] [type]",
    },
    {
        .name = "dump",
        .handler = handle_etm_dump_command,
        .mode = COMMAND_EXEC,
        .help = "dump captured trace data to file",
        .usage = "filename",
    },
    {
        .name = "load",
        .handler = handle_etm_load_command,
        .mode = COMMAND_EXEC,
        .usage = "",
        .help = "load trace data for analysis <file>",
    },
    COMMAND_REGISTRATION_DONE
};
 
static int etm_register_user_commands(struct command_context *cmd_ctx)
{
    return register_commands(cmd_ctx, "etm", etm_exec_command_handlers);
}