lakemont.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/*
 * Copyright(c) 2013-2016 Intel Corporation.
 *
 * Adrian Burns (adrian.burns@intel.com)
 * Thomas Faust (thomas.faust@intel.com)
 * Ivan De Cesaris (ivan.de.cesaris@intel.com)
 * Julien Carreno (julien.carreno@intel.com)
 * Jeffrey Maxwell (jeffrey.r.maxwell@intel.com)
 * Jessica Gomez (jessica.gomez.hernandez@intel.com)
 *
 * Contact Information:
 * Intel Corporation
 */
 
/*
 * @file
 * This implements the probemode operations for Lakemont 1 (LMT1).
 */
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <helper/log.h>
 
#include "target.h"
#include "target_type.h"
#include "lakemont.h"
#include "register.h"
#include "breakpoints.h"
#include "x86_32_common.h"
 
static int irscan(struct target *t, uint8_t *out,
            uint8_t *in, uint8_t ir_len);
static int drscan(struct target *t, uint8_t *out, uint8_t *in, uint8_t len);
static int save_context(struct target *target);
static int restore_context(struct target *target);
static uint32_t get_tapstatus(struct target *t);
static int enter_probemode(struct target *t);
static int exit_probemode(struct target *t);
static int halt_prep(struct target *t);
static int do_halt(struct target *t);
static int do_resume(struct target *t);
static int read_all_core_hw_regs(struct target *t);
static int write_all_core_hw_regs(struct target *t);
static int read_hw_reg(struct target *t,
            int reg, uint32_t *regval, uint8_t cache);
static int write_hw_reg(struct target *t,
            int reg, uint32_t regval, uint8_t cache);
static struct reg_cache *lakemont_build_reg_cache
            (struct target *target);
static int submit_reg_pir(struct target *t, int num);
static int submit_instruction_pir(struct target *t, int num);
static int submit_pir(struct target *t, uint64_t op);
static int lakemont_get_core_reg(struct reg *reg);
static int lakemont_set_core_reg(struct reg *reg, uint8_t *buf);
 
static struct scan_blk scan;
 
/* registers and opcodes for register access, pm_idx is used to identify the
 * registers that are modified for lakemont probemode specific operations
 */
static const struct {
    uint8_t id;
    const char *name;
    uint64_t op;
    uint8_t pm_idx;
    unsigned bits;
    enum reg_type type;
    const char *group;
    const char *feature;
} regs[] = {
    /* general purpose registers */
    { EAX, "eax", 0x000000D01D660000, 0, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { ECX, "ecx", 0x000000501D660000, 1, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { EDX, "edx", 0x000000901D660000, 2, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { EBX, "ebx", 0x000000101D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { ESP, "esp", 0x000000E01D660000, NOT_PMREG, 32, REG_TYPE_DATA_PTR, "general", "org.gnu.gdb.i386.core" },
    { EBP, "ebp", 0x000000601D660000, NOT_PMREG, 32, REG_TYPE_DATA_PTR, "general", "org.gnu.gdb.i386.core" },
    { ESI, "esi", 0x000000A01D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { EDI, "edi", 0x000000201D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
 
    /* instruction pointer & flags */
    { EIP, "eip", 0x000000C01D660000, 3, 32, REG_TYPE_CODE_PTR, "general", "org.gnu.gdb.i386.core" },
    { EFLAGS, "eflags", 0x000000401D660000, 4, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
 
    /* segment registers */
    { CS, "cs", 0x000000281D660000, 5, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { SS, "ss", 0x000000C81D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { DS, "ds", 0x000000481D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { ES, "es", 0x000000A81D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { FS, "fs", 0x000000881D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { GS, "gs", 0x000000081D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
 
    /* floating point unit registers - not accessible via JTAG - here to satisfy GDB */
    { ST0, "st0", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { ST1, "st1", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { ST2, "st2", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { ST3, "st3", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { ST4, "st4", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { ST5, "st5", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { ST6, "st6", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { ST7, "st7", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { FCTRL, "fctrl", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { FSTAT, "fstat", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { FTAG, "ftag", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { FISEG, "fiseg", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { FIOFF, "fioff", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { FOSEG, "foseg", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { FOOFF, "fooff", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
    { FOP, "fop", 0x0, NOT_AVAIL_REG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.core" },
 
    /* control registers */
    { CR0, "cr0", 0x000000001D660000, 6, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { CR2, "cr2", 0x000000BC1D660000, 7, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { CR3, "cr3", 0x000000801D660000, 8, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { CR4, "cr4", 0x0000002C1D660000, 9, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
 
    /* debug registers */
    { DR0, "dr0", 0x0000007C1D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { DR1, "dr1", 0x000000FC1D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { DR2, "dr2", 0x000000021D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { DR3, "dr3", 0x000000821D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { DR6, "dr6", 0x000000301D660000, 10, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { DR7, "dr7", 0x000000B01D660000, 11, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
 
    /* descriptor tables */
    { IDTB, "idtbase", 0x000000581D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { IDTL, "idtlimit", 0x000000D81D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { IDTAR, "idtar", 0x000000981D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { GDTB, "gdtbase", 0x000000B81D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { GDTL, "gdtlimit", 0x000000781D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { GDTAR, "gdtar", 0x000000381D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { TR, "tr", 0x000000701D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { LDTR, "ldtr", 0x000000F01D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { LDTB, "ldbase", 0x000000041D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { LDTL, "ldlimit", 0x000000841D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { LDTAR, "ldtar", 0x000000F81D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
 
    /* segment registers */
    { CSB, "csbase", 0x000000F41D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { CSL, "cslimit", 0x0000000C1D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { CSAR, "csar", 0x000000741D660000, 12, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { DSB, "dsbase", 0x000000941D660000, 13, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { DSL, "dslimit", 0x000000541D660000, 14, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { DSAR, "dsar", 0x000000141D660000, 15, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { ESB, "esbase", 0x0000004C1D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { ESL, "eslimit", 0x000000CC1D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { ESAR, "esar", 0x0000008C1D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { FSB, "fsbase", 0x000000641D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { FSL, "fslimit", 0x000000E41D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { FSAR, "fsar", 0x000000A41D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { GSB, "gsbase", 0x000000C41D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { GSL, "gslimit", 0x000000241D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { GSAR, "gsar", 0x000000441D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { SSB, "ssbase", 0x000000341D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { SSL, "sslimit", 0x000000B41D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { SSAR, "ssar", 0x000000D41D660000, 16, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { TSSB, "tssbase", 0x000000E81D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { TSSL, "tsslimit", 0x000000181D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    { TSSAR, "tssar", 0x000000681D660000, NOT_PMREG, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
    /* probemode control register */
    { PMCR, "pmcr", 0x000000421D660000, 17, 32, REG_TYPE_INT32, "general", "org.gnu.gdb.i386.sys" },
};
 
static const struct {
    uint8_t id;
    const char *name;
    uint64_t op;
} instructions[] = {
    /* memory read/write */
    { MEMRDB32, "MEMRDB32", 0x0909090909090851 },
    { MEMRDB16, "MEMRDB16", 0x09090909090851E6 },
    { MEMRDH32, "MEMRDH32", 0x090909090908D166 },
    { MEMRDH16, "MEMRDH16", 0x090909090908D1E6 },
    { MEMRDW32, "MEMRDW32", 0x09090909090908D1 },
    { MEMRDW16, "MEMRDW16", 0x0909090908D1E666 },
    { MEMWRB32, "MEMWRB32", 0x0909090909090811 },
    { MEMWRB16, "MEMWRB16", 0x09090909090811E6 },
    { MEMWRH32, "MEMWRH32", 0x0909090909089166 },
    { MEMWRH16, "MEMWRH16", 0x09090909090891E6 },
    { MEMWRW32, "MEMWRW32", 0x0909090909090891 },
    { MEMWRW16, "MEMWRW16", 0x090909090891E666 },
    /* IO read/write */
    { IORDB32, "IORDB32", 0x0909090909090937 },
    { IORDB16, "IORDB16", 0x09090909090937E6 },
    { IORDH32, "IORDH32", 0x090909090909B766 },
    { IORDH16, "IORDH16", 0x090909090909B7E6 },
    { IORDW32, "IORDW32", 0x09090909090909B7 },
    { IORDW16, "IORDW16", 0x0909090909B7E666 },
    { IOWRB32, "IOWRB32", 0x0909090909090977 },
    { IOWRB16, "IOWRB16", 0x09090909090977E6 },
    { IOWRH32, "IOWRH32", 0x090909090909F766 },
    { IOWRH16, "IOWRH16", 0x090909090909F7E6 },
    { IOWRW32, "IOWRW32", 0x09090909090909F7 },
    { IOWRW16, "IOWRW16", 0x0909090909F7E666 },
    /* lakemont1 core shadow ram access opcodes */
    { SRAMACCESS, "SRAMACCESS", 0x0000000E9D660000 },
    { SRAM2PDR, "SRAM2PDR", 0x4CF0000000000000 },
    { PDR2SRAM, "PDR2SRAM", 0x0CF0000000000000 },
    { WBINVD, "WBINVD", 0x09090909090990F0 },
};
 
bool check_not_halted(const struct target *t)
{
    bool halted = t->state == TARGET_HALTED;
    if (!halted)
        LOG_ERROR("target running, halt it first");
    return !halted;
}
 
static int irscan(struct target *t, uint8_t *out,
            uint8_t *in, uint8_t ir_len)
{
    int retval = ERROR_OK;
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    if (!t->tap) {
        retval = ERROR_FAIL;
        LOG_ERROR("%s invalid target tap", __func__);
        return retval;
    }
    if (ir_len != t->tap->ir_length) {
        retval = ERROR_FAIL;
        if (t->tap->enabled)
            LOG_ERROR("%s tap enabled but tap irlen=%d",
                    __func__, t->tap->ir_length);
        else
            LOG_ERROR("%s tap not enabled and irlen=%d",
                    __func__, t->tap->ir_length);
        return retval;
    }
    struct scan_field *fields = &scan.field;
    fields->num_bits = ir_len;
    fields->out_value = out;
    fields->in_value = in;
    jtag_add_ir_scan(x86_32->curr_tap, fields, TAP_IDLE);
    if (x86_32->flush) {
        retval = jtag_execute_queue();
        if (retval != ERROR_OK)
            LOG_ERROR("%s failed to execute queue", __func__);
    }
    return retval;
}
 
static int drscan(struct target *t, uint8_t *out, uint8_t *in, uint8_t len)
{
    int retval = ERROR_OK;
    uint64_t data = 0;
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    if (!t->tap) {
        retval = ERROR_FAIL;
        LOG_ERROR("%s invalid target tap", __func__);
        return retval;
    }
    if (len > MAX_SCAN_SIZE || 0 == len) {
        retval = ERROR_FAIL;
        LOG_ERROR("%s data len is %d bits, max is %d bits",
                __func__, len, MAX_SCAN_SIZE);
        return retval;
    }
    struct scan_field *fields = &scan.field;
    fields->out_value = out;
    fields->in_value = in;
    fields->num_bits = len;
    jtag_add_dr_scan(x86_32->curr_tap, 1, fields, TAP_IDLE);
    if (x86_32->flush) {
        retval = jtag_execute_queue();
        if (retval != ERROR_OK) {
            LOG_ERROR("%s drscan failed to execute queue", __func__);
            return retval;
        }
    }
    if (in) {
        if (len >= 8) {
            for (int n = (len / 8) - 1 ; n >= 0; n--)
                data = (data << 8) + *(in+n);
        } else
            LOG_DEBUG("dr in 0x%02" PRIx8, *in);
    } else {
        LOG_ERROR("%s no drscan data", __func__);
        retval = ERROR_FAIL;
    }
    return retval;
}
 
static int save_context(struct target *t)
{
    int err;
    /* read core registers from lakemont sram */
    err = read_all_core_hw_regs(t);
    if (err != ERROR_OK) {
        LOG_ERROR("%s error reading regs", __func__);
        return err;
    }
    return ERROR_OK;
}
 
static int restore_context(struct target *t)
{
    int err = ERROR_OK;
    uint32_t i;
    struct x86_32_common *x86_32 = target_to_x86_32(t);
 
    /* write core regs into the core PM SRAM from the reg_cache */
    err = write_all_core_hw_regs(t);
    if (err != ERROR_OK) {
        LOG_ERROR("%s error writing regs", __func__);
        return err;
    }
 
    for (i = 0; i < (x86_32->cache->num_regs); i++) {
        x86_32->cache->reg_list[i].dirty = false;
        x86_32->cache->reg_list[i].valid = false;
    }
    return err;
}
 
/*
 * we keep reg_cache in sync with hardware at halt/resume time, we avoid
 * writing to real hardware here because pm_regs reflects the hardware
 * while we are halted then reg_cache syncs with hw on resume
 * TODO - in order for "reg eip force" to work it assume get/set reads
 * and writes from hardware, may be other reasons also because generally
 * other openocd targets read/write from hardware in get/set - watch this!
 */
static int lakemont_get_core_reg(struct reg *reg)
{
    int retval = ERROR_OK;
    struct lakemont_core_reg *lakemont_reg = reg->arch_info;
    struct target *t = lakemont_reg->target;
    if (check_not_halted(t))
        return ERROR_TARGET_NOT_HALTED;
    LOG_DEBUG("reg=%s, value=0x%08" PRIx32, reg->name,
            buf_get_u32(reg->value, 0, 32));
    return retval;
}
 
static int lakemont_set_core_reg(struct reg *reg, uint8_t *buf)
{
    struct lakemont_core_reg *lakemont_reg = reg->arch_info;
    struct target *t = lakemont_reg->target;
    uint32_t value = buf_get_u32(buf, 0, 32);
    LOG_DEBUG("reg=%s, newval=0x%08" PRIx32, reg->name, value);
    if (check_not_halted(t))
        return ERROR_TARGET_NOT_HALTED;
    buf_set_u32(reg->value, 0, 32, value);
    reg->dirty = true;
    reg->valid = true;
    return ERROR_OK;
}
 
static const struct reg_arch_type lakemont_reg_type = {
    /* these get called if reg_cache doesn't have a "valid" value
     * of an individual reg eg "reg eip" but not for "reg" block
     */
    .get = lakemont_get_core_reg,
    .set = lakemont_set_core_reg,
};
 
struct reg_cache *lakemont_build_reg_cache(struct target *t)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    int num_regs = ARRAY_SIZE(regs);
    struct reg_cache **cache_p = register_get_last_cache_p(&t->reg_cache);
    struct reg_cache *cache = malloc(sizeof(struct reg_cache));
    struct reg *reg_list = calloc(num_regs, sizeof(struct reg));
    struct lakemont_core_reg *arch_info = malloc(sizeof(struct lakemont_core_reg) * num_regs);
    struct reg_feature *feature;
    int i;
 
    if (!cache || !reg_list || !arch_info) {
        free(cache);
        free(reg_list);
        free(arch_info);
        LOG_ERROR("%s out of memory", __func__);
        return NULL;
    }
 
    /* Build the process context cache */
    cache->name = "lakemont registers";
    cache->next = NULL;
    cache->reg_list = reg_list;
    cache->num_regs = num_regs;
    (*cache_p) = cache;
    x86_32->cache = cache;
 
    for (i = 0; i < num_regs; i++) {
        arch_info[i].target = t;
        arch_info[i].x86_32_common = x86_32;
        arch_info[i].op = regs[i].op;
        arch_info[i].pm_idx = regs[i].pm_idx;
        reg_list[i].name = regs[i].name;
        reg_list[i].size = 32;
        reg_list[i].value = calloc(1, 4);
        reg_list[i].dirty = false;
        reg_list[i].valid = false;
        reg_list[i].type = &lakemont_reg_type;
        reg_list[i].arch_info = &arch_info[i];
 
        reg_list[i].group = regs[i].group;
        reg_list[i].number = i;
        reg_list[i].exist = true;
        reg_list[i].caller_save = true; /* gdb defaults to true */
 
        feature = calloc(1, sizeof(struct reg_feature));
        if (feature) {
            feature->name = regs[i].feature;
            reg_list[i].feature = feature;
        } else
            LOG_ERROR("%s unable to allocate feature list", __func__);
 
        reg_list[i].reg_data_type = calloc(1, sizeof(struct reg_data_type));
        if (reg_list[i].reg_data_type)
            reg_list[i].reg_data_type->type = regs[i].type;
        else
            LOG_ERROR("%s unable to allocate reg type list", __func__);
    }
    return cache;
}
 
static uint32_t get_tapstatus(struct target *t)
{
    scan.out[0] = TAPSTATUS;
    if (irscan(t, scan.out, NULL, LMT_IRLEN) != ERROR_OK)
        return 0;
    if (drscan(t, NULL, scan.out, TS_SIZE) != ERROR_OK)
        return 0;
    return buf_get_u32(scan.out, 0, 32);
}
 
static int enter_probemode(struct target *t)
{
    uint32_t tapstatus = 0;
    int retries = 100;
 
    tapstatus = get_tapstatus(t);
    LOG_DEBUG("TS before PM enter = 0x%08" PRIx32, tapstatus);
    if (tapstatus & TS_PM_BIT) {
        LOG_DEBUG("core already in probemode");
        return ERROR_OK;
    }
    scan.out[0] = PROBEMODE;
    if (irscan(t, scan.out, NULL, LMT_IRLEN) != ERROR_OK)
        return ERROR_FAIL;
    scan.out[0] = 1;
    if (drscan(t, scan.out, scan.in, 1) != ERROR_OK)
        return ERROR_FAIL;
 
    while (retries--) {
        tapstatus = get_tapstatus(t);
        LOG_DEBUG("TS after PM enter = 0x%08" PRIx32, tapstatus);
        if ((tapstatus & TS_PM_BIT) && (!(tapstatus & TS_EN_PM_BIT)))
            return ERROR_OK;
    }
 
    LOG_ERROR("%s PM enter error, tapstatus = 0x%08" PRIx32
            , __func__, tapstatus);
    return ERROR_FAIL;
}
 
static int exit_probemode(struct target *t)
{
    uint32_t tapstatus = get_tapstatus(t);
    LOG_DEBUG("TS before PM exit = 0x%08" PRIx32, tapstatus);
 
    if (!(tapstatus & TS_PM_BIT)) {
        LOG_USER("core not in PM");
        return ERROR_OK;
    }
    scan.out[0] = PROBEMODE;
    if (irscan(t, scan.out, NULL, LMT_IRLEN) != ERROR_OK)
        return ERROR_FAIL;
    scan.out[0] = 0;
    if (drscan(t, scan.out, scan.in, 1) != ERROR_OK)
        return ERROR_FAIL;
    return ERROR_OK;
}
 
/* do whats needed to properly enter probemode for debug on lakemont */
static int halt_prep(struct target *t)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    if (write_hw_reg(t, DSB, PM_DSB, 0) != ERROR_OK)
        return ERROR_FAIL;
    LOG_DEBUG("write %s 0x%08" PRIx32, regs[DSB].name, PM_DSB);
    if (write_hw_reg(t, DSL, PM_DSL, 0) != ERROR_OK)
        return ERROR_FAIL;
    LOG_DEBUG("write %s 0x%08" PRIx32, regs[DSL].name, PM_DSL);
    if (write_hw_reg(t, DSAR, PM_DSAR, 0) != ERROR_OK)
        return ERROR_FAIL;
    LOG_DEBUG("write DSAR 0x%08" PRIx32, PM_DSAR);
    if (write_hw_reg(t, CSB, PM_DSB, 0) != ERROR_OK)
        return ERROR_FAIL;
    LOG_DEBUG("write %s 0x%08" PRIx32, regs[CSB].name, PM_DSB);
    if (write_hw_reg(t, CSL, PM_DSL, 0) != ERROR_OK)
        return ERROR_FAIL;
    LOG_DEBUG("write %s 0x%08" PRIx32, regs[CSL].name, PM_DSL);
    if (write_hw_reg(t, DR7, PM_DR7, 0) != ERROR_OK)
        return ERROR_FAIL;
    LOG_DEBUG("write DR7 0x%08" PRIx32, PM_DR7);
 
    uint32_t eflags = buf_get_u32(x86_32->cache->reg_list[EFLAGS].value, 0, 32);
    uint32_t csar = buf_get_u32(x86_32->cache->reg_list[CSAR].value, 0, 32);
    uint32_t ssar = buf_get_u32(x86_32->cache->reg_list[SSAR].value, 0, 32);
    uint32_t cr0 = buf_get_u32(x86_32->cache->reg_list[CR0].value, 0, 32);
 
    /* clear VM86 and IF bits if they are set */
    LOG_DEBUG("EFLAGS = 0x%08" PRIx32 ", VM86 = %d, IF = %d", eflags,
            eflags & EFLAGS_VM86 ? 1 : 0,
            eflags & EFLAGS_IF ? 1 : 0);
    if ((eflags & EFLAGS_VM86) || (eflags & EFLAGS_IF)) {
        x86_32->pm_regs[I(EFLAGS)] = eflags & ~(EFLAGS_VM86 | EFLAGS_IF);
        if (write_hw_reg(t, EFLAGS, x86_32->pm_regs[I(EFLAGS)], 0) != ERROR_OK)
            return ERROR_FAIL;
        LOG_DEBUG("EFLAGS now = 0x%08" PRIx32 ", VM86 = %d, IF = %d",
                x86_32->pm_regs[I(EFLAGS)],
                x86_32->pm_regs[I(EFLAGS)] & EFLAGS_VM86 ? 1 : 0,
                x86_32->pm_regs[I(EFLAGS)] & EFLAGS_IF ? 1 : 0);
    }
 
    /* set CPL to 0 for memory access */
    if (csar & CSAR_DPL) {
        x86_32->pm_regs[I(CSAR)] = csar & ~CSAR_DPL;
        if (write_hw_reg(t, CSAR, x86_32->pm_regs[I(CSAR)], 0) != ERROR_OK)
            return ERROR_FAIL;
        LOG_DEBUG("write CSAR_CPL to 0 0x%08" PRIx32, x86_32->pm_regs[I(CSAR)]);
    }
    if (ssar & SSAR_DPL) {
        x86_32->pm_regs[I(SSAR)] = ssar & ~SSAR_DPL;
        if (write_hw_reg(t, SSAR, x86_32->pm_regs[I(SSAR)], 0) != ERROR_OK)
            return ERROR_FAIL;
        LOG_DEBUG("write SSAR_CPL to 0 0x%08" PRIx32, x86_32->pm_regs[I(SSAR)]);
    }
 
    /* if cache's are enabled, disable and flush, depending on the core version */
    if (!(x86_32->core_type == LMT3_5) && !(cr0 & CR0_CD)) {
        LOG_DEBUG("caching enabled CR0 = 0x%08" PRIx32, cr0);
        if (cr0 & CR0_PG) {
            x86_32->pm_regs[I(CR0)] = cr0 & ~CR0_PG;
            if (write_hw_reg(t, CR0, x86_32->pm_regs[I(CR0)], 0) != ERROR_OK)
                return ERROR_FAIL;
            LOG_DEBUG("cleared paging CR0_PG = 0x%08" PRIx32, x86_32->pm_regs[I(CR0)]);
            /* submit wbinvd to flush cache */
            if (submit_reg_pir(t, WBINVD) != ERROR_OK)
                return ERROR_FAIL;
            x86_32->pm_regs[I(CR0)] =
                x86_32->pm_regs[I(CR0)] | (CR0_CD | CR0_NW | CR0_PG);
            if (write_hw_reg(t, CR0, x86_32->pm_regs[I(CR0)], 0) != ERROR_OK)
                return ERROR_FAIL;
            LOG_DEBUG("set CD, NW and PG, CR0 = 0x%08" PRIx32, x86_32->pm_regs[I(CR0)]);
        }
    }
    return ERROR_OK;
}
 
static int do_halt(struct target *t)
{
    /* needs proper handling later if doing a halt errors out */
    t->state = TARGET_DEBUG_RUNNING;
    if (enter_probemode(t) != ERROR_OK)
        return ERROR_FAIL;
 
    return lakemont_update_after_probemode_entry(t);
}
 
/* we need to expose the update to be able to complete the reset at SoC level */
int lakemont_update_after_probemode_entry(struct target *t)
{
    if (save_context(t) != ERROR_OK)
        return ERROR_FAIL;
    if (halt_prep(t) != ERROR_OK)
        return ERROR_FAIL;
    t->state = TARGET_HALTED;
 
    return target_call_event_callbacks(t, TARGET_EVENT_HALTED);
}
 
static int do_resume(struct target *t)
{
    /* needs proper handling later */
    t->state = TARGET_DEBUG_RUNNING;
    if (restore_context(t) != ERROR_OK)
        return ERROR_FAIL;
    if (exit_probemode(t) != ERROR_OK)
        return ERROR_FAIL;
    t->state = TARGET_RUNNING;
 
    t->debug_reason = DBG_REASON_NOTHALTED;
    LOG_USER("target running");
 
    return target_call_event_callbacks(t, TARGET_EVENT_RESUMED);
}
 
static int read_all_core_hw_regs(struct target *t)
{
    int err;
    uint32_t regval;
    unsigned i;
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    for (i = 0; i < (x86_32->cache->num_regs); i++) {
        if (regs[i].pm_idx == NOT_AVAIL_REG)
            continue;
        err = read_hw_reg(t, regs[i].id, &regval, 1);
        if (err != ERROR_OK) {
            LOG_ERROR("%s error saving reg %s",
                    __func__, x86_32->cache->reg_list[i].name);
            return err;
        }
    }
    LOG_DEBUG("read_all_core_hw_regs read %u registers ok", i);
    return ERROR_OK;
}
 
static int write_all_core_hw_regs(struct target *t)
{
    int err;
    unsigned i;
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    for (i = 0; i < (x86_32->cache->num_regs); i++) {
        if (regs[i].pm_idx == NOT_AVAIL_REG)
            continue;
        err = write_hw_reg(t, i, 0, 1);
        if (err != ERROR_OK) {
            LOG_ERROR("%s error restoring reg %s",
                    __func__, x86_32->cache->reg_list[i].name);
            return err;
        }
    }
    LOG_DEBUG("write_all_core_hw_regs wrote %u registers ok", i);
    return ERROR_OK;
}
 
/* read reg from lakemont core shadow ram, update reg cache if needed */
static int read_hw_reg(struct target *t, int reg, uint32_t *regval, uint8_t cache)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    struct lakemont_core_reg *arch_info;
    arch_info = x86_32->cache->reg_list[reg].arch_info;
    x86_32->flush = 0; /* don't flush scans till we have a batch */
    if (submit_reg_pir(t, reg) != ERROR_OK)
        return ERROR_FAIL;
    if (submit_instruction_pir(t, SRAMACCESS) != ERROR_OK)
        return ERROR_FAIL;
    if (submit_instruction_pir(t, SRAM2PDR) != ERROR_OK)
        return ERROR_FAIL;
    x86_32->flush = 1;
    scan.out[0] = RDWRPDR;
    if (irscan(t, scan.out, NULL, LMT_IRLEN) != ERROR_OK)
        return ERROR_FAIL;
    if (drscan(t, NULL, scan.out, PDR_SIZE) != ERROR_OK)
        return ERROR_FAIL;
 
    jtag_add_sleep(DELAY_SUBMITPIR);
    *regval = buf_get_u32(scan.out, 0, 32);
    if (cache) {
        buf_set_u32(x86_32->cache->reg_list[reg].value, 0, 32, *regval);
        x86_32->cache->reg_list[reg].valid = true;
        x86_32->cache->reg_list[reg].dirty = false;
    }
    LOG_DEBUG("reg=%s, op=0x%016" PRIx64 ", val=0x%08" PRIx32,
            x86_32->cache->reg_list[reg].name,
            arch_info->op,
            *regval);
    return ERROR_OK;
}
 
/* write lakemont core shadow ram reg, update reg cache if needed */
static int write_hw_reg(struct target *t, int reg, uint32_t regval, uint8_t cache)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    struct lakemont_core_reg *arch_info;
    arch_info = x86_32->cache->reg_list[reg].arch_info;
 
    uint8_t reg_buf[4];
    if (cache)
        regval = buf_get_u32(x86_32->cache->reg_list[reg].value, 0, 32);
    buf_set_u32(reg_buf, 0, 32, regval);
    LOG_DEBUG("reg=%s, op=0x%016" PRIx64 ", val=0x%08" PRIx32,
            x86_32->cache->reg_list[reg].name,
            arch_info->op,
            regval);
 
    x86_32->flush = 0; /* don't flush scans till we have a batch */
    if (submit_reg_pir(t, reg) != ERROR_OK)
        return ERROR_FAIL;
    if (submit_instruction_pir(t, SRAMACCESS) != ERROR_OK)
        return ERROR_FAIL;
    scan.out[0] = RDWRPDR;
    if (irscan(t, scan.out, NULL, LMT_IRLEN) != ERROR_OK)
        return ERROR_FAIL;
    if (drscan(t, reg_buf, scan.out, PDR_SIZE) != ERROR_OK)
        return ERROR_FAIL;
    x86_32->flush = 1;
    if (submit_instruction_pir(t, PDR2SRAM) != ERROR_OK)
        return ERROR_FAIL;
 
    /* we are writing from the cache so ensure we reset flags */
    if (cache) {
        x86_32->cache->reg_list[reg].dirty = false;
        x86_32->cache->reg_list[reg].valid = false;
    }
    return ERROR_OK;
}
 
static bool is_paging_enabled(struct target *t)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    if (x86_32->pm_regs[I(CR0)] & CR0_PG)
        return true;
    else
        return false;
}
 
static uint8_t get_num_user_regs(struct target *t)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    return x86_32->cache->num_regs;
}
/* value of the CR0.PG (paging enabled) bit influences memory reads/writes */
static int disable_paging(struct target *t)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    x86_32->pm_regs[I(CR0)] = x86_32->pm_regs[I(CR0)] & ~CR0_PG;
    int err = x86_32->write_hw_reg(t, CR0, x86_32->pm_regs[I(CR0)], 0);
    if (err != ERROR_OK) {
        LOG_ERROR("%s error disabling paging", __func__);
        return err;
    }
    return err;
}
 
static int enable_paging(struct target *t)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    x86_32->pm_regs[I(CR0)] = (x86_32->pm_regs[I(CR0)] | CR0_PG);
    int err = x86_32->write_hw_reg(t, CR0, x86_32->pm_regs[I(CR0)], 0);
    if (err != ERROR_OK) {
        LOG_ERROR("%s error enabling paging", __func__);
        return err;
    }
    return err;
}
 
static bool sw_bpts_supported(struct target *t)
{
    uint32_t tapstatus = get_tapstatus(t);
    if (tapstatus & TS_SBP_BIT)
        return true;
    else
        return false;
}
 
static int transaction_status(struct target *t)
{
    uint32_t tapstatus = get_tapstatus(t);
    if ((TS_EN_PM_BIT | TS_PRDY_BIT) & tapstatus) {
        LOG_ERROR("%s transaction error tapstatus = 0x%08" PRIx32
                , __func__, tapstatus);
        return ERROR_FAIL;
    } else {
        return ERROR_OK;
    }
}
 
static int submit_instruction(struct target *t, int num)
{
    int err = submit_instruction_pir(t, num);
    if (err != ERROR_OK) {
        LOG_ERROR("%s error submitting pir", __func__);
        return err;
    }
    return err;
}
 
static int submit_reg_pir(struct target *t, int num)
{
    LOG_DEBUG("reg %s op=0x%016" PRIx64, regs[num].name, regs[num].op);
    int err = submit_pir(t, regs[num].op);
    if (err != ERROR_OK) {
        LOG_ERROR("%s error submitting pir", __func__);
        return err;
    }
    return err;
}
 
static int submit_instruction_pir(struct target *t, int num)
{
    LOG_DEBUG("%s op=0x%016" PRIx64, instructions[num].name,
            instructions[num].op);
    int err = submit_pir(t, instructions[num].op);
    if (err != ERROR_OK) {
        LOG_ERROR("%s error submitting pir", __func__);
        return err;
    }
    return err;
}
 
/*
 * PIR (Probe Mode Instruction Register), SUBMITPIR is an "IR only" TAP
 * command; there is no corresponding data register
 */
static int submit_pir(struct target *t, uint64_t op)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
 
    uint8_t op_buf[8];
    buf_set_u64(op_buf, 0, 64, op);
    int flush = x86_32->flush;
    x86_32->flush = 0;
    scan.out[0] = WRPIR;
    if (irscan(t, scan.out, NULL, LMT_IRLEN) != ERROR_OK)
        return ERROR_FAIL;
    if (drscan(t, op_buf, scan.out, PIR_SIZE) != ERROR_OK)
        return ERROR_FAIL;
    scan.out[0] = SUBMITPIR;
    x86_32->flush = flush;
    if (irscan(t, scan.out, NULL, LMT_IRLEN) != ERROR_OK)
        return ERROR_FAIL;
    jtag_add_sleep(DELAY_SUBMITPIR);
    return ERROR_OK;
}
 
int lakemont_init_target(struct command_context *cmd_ctx, struct target *t)
{
    lakemont_build_reg_cache(t);
    t->state = TARGET_RUNNING;
    t->debug_reason = DBG_REASON_NOTHALTED;
    return ERROR_OK;
}
 
int lakemont_init_arch_info(struct target *t, struct x86_32_common *x86_32)
{
    x86_32->submit_instruction = submit_instruction;
    x86_32->transaction_status = transaction_status;
    x86_32->read_hw_reg = read_hw_reg;
    x86_32->write_hw_reg = write_hw_reg;
    x86_32->sw_bpts_supported = sw_bpts_supported;
    x86_32->get_num_user_regs = get_num_user_regs;
    x86_32->is_paging_enabled = is_paging_enabled;
    x86_32->disable_paging = disable_paging;
    x86_32->enable_paging = enable_paging;
    return ERROR_OK;
}
 
int lakemont_poll(struct target *t)
{
    /* LMT1 PMCR register currently allows code breakpoints, data breakpoints,
     * single stepping and shutdowns to be redirected to PM but does not allow
     * redirecting into PM as a result of SMM enter and SMM exit
     */
    uint32_t ts = get_tapstatus(t);
 
    if (ts == 0xFFFFFFFF && t->state != TARGET_DEBUG_RUNNING) {
        /* something is wrong here */
        LOG_ERROR("tapstatus invalid - scan_chain serialization or locked JTAG access issues");
        /* TODO: Give a hint that unlocking is wrong or maybe a
         * 'jtag arp_init' helps
         */
        t->state = TARGET_DEBUG_RUNNING;
        return ERROR_OK;
    }
 
    if (t->state == TARGET_HALTED && (!(ts & TS_PM_BIT))) {
        LOG_INFO("target running for unknown reason");
        t->state = TARGET_RUNNING;
    }
 
    if (t->state == TARGET_RUNNING &&
        t->state != TARGET_DEBUG_RUNNING) {
 
        if ((ts & TS_PM_BIT) && (ts & TS_PMCR_BIT)) {
 
            LOG_DEBUG("redirect to PM, tapstatus=0x%08" PRIx32, get_tapstatus(t));
 
            t->state = TARGET_DEBUG_RUNNING;
            if (save_context(t) != ERROR_OK)
                return ERROR_FAIL;
            if (halt_prep(t) != ERROR_OK)
                return ERROR_FAIL;
            t->state = TARGET_HALTED;
            t->debug_reason = DBG_REASON_UNDEFINED;
 
            struct x86_32_common *x86_32 = target_to_x86_32(t);
            uint32_t eip = buf_get_u32(x86_32->cache->reg_list[EIP].value, 0, 32);
            uint32_t dr6 = buf_get_u32(x86_32->cache->reg_list[DR6].value, 0, 32);
            uint32_t hwbreakpoint = (uint32_t)-1;
 
            if (dr6 & DR6_BRKDETECT_0)
                hwbreakpoint = 0;
            if (dr6 & DR6_BRKDETECT_1)
                hwbreakpoint = 1;
            if (dr6 & DR6_BRKDETECT_2)
                hwbreakpoint = 2;
            if (dr6 & DR6_BRKDETECT_3)
                hwbreakpoint = 3;
 
            if (hwbreakpoint != (uint32_t)-1) {
                uint32_t dr7 = buf_get_u32(x86_32->cache->reg_list[DR7].value, 0, 32);
                uint32_t type = dr7 & (0x03 << (DR7_RW_SHIFT + hwbreakpoint*DR7_RW_LEN_SIZE));
                if (type == DR7_BP_EXECUTE) {
                    LOG_USER("hit hardware breakpoint (hwreg=%" PRIu32 ") at 0x%08" PRIx32, hwbreakpoint, eip);
                } else {
                    uint32_t address = 0;
                    switch (hwbreakpoint) {
                    default:
                    case 0:
                        address = buf_get_u32(x86_32->cache->reg_list[DR0].value, 0, 32);
                    break;
                    case 1:
                        address = buf_get_u32(x86_32->cache->reg_list[DR1].value, 0, 32);
                    break;
                    case 2:
                        address = buf_get_u32(x86_32->cache->reg_list[DR2].value, 0, 32);
                    break;
                    case 3:
                        address = buf_get_u32(x86_32->cache->reg_list[DR3].value, 0, 32);
                    break;
                    }
                    LOG_USER("hit '%s' watchpoint for 0x%08" PRIx32 " (hwreg=%" PRIu32 ") at 0x%08" PRIx32,
                                type == DR7_BP_WRITE ? "write" : "access", address,
                                hwbreakpoint, eip);
                }
                t->debug_reason = DBG_REASON_BREAKPOINT;
            } else {
                /* Check if the target hit a software breakpoint.
                 * ! Watch out: EIP is currently pointing after the breakpoint opcode
                 */
                struct breakpoint *bp = NULL;
                bp = breakpoint_find(t, eip-1);
                if (bp) {
                    t->debug_reason = DBG_REASON_BREAKPOINT;
                    if (bp->type == BKPT_SOFT) {
                        /* The EIP is now pointing the next byte after the
                         * breakpoint instruction. This needs to be corrected.
                         */
                        buf_set_u32(x86_32->cache->reg_list[EIP].value, 0, 32, eip-1);
                        x86_32->cache->reg_list[EIP].dirty = true;
                        x86_32->cache->reg_list[EIP].valid = true;
                        LOG_USER("hit software breakpoint at 0x%08" PRIx32, eip-1);
                    } else {
                        /* it's not a hardware breakpoint (checked already in DR6 state)
                         * and it's also not a software breakpoint ...
                         */
                        LOG_USER("hit unknown breakpoint at 0x%08" PRIx32, eip);
                    }
                } else {
 
                    /* There is also the case that we hit an breakpoint instruction,
                     * which was not set by us. This needs to be handled be the
                     * application that introduced the breakpoint.
                     */
 
                    LOG_USER("unknown break reason at 0x%08" PRIx32, eip);
                }
            }
 
            return target_call_event_callbacks(t, TARGET_EVENT_HALTED);
        }
    }
 
    return ERROR_OK;
}
 
int lakemont_arch_state(struct target *t)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
 
    LOG_USER("target halted due to %s at 0x%08" PRIx32 " in %s mode",
            debug_reason_name(t),
            buf_get_u32(x86_32->cache->reg_list[EIP].value, 0, 32),
            (buf_get_u32(x86_32->cache->reg_list[CR0].value, 0, 32) & CR0_PE) ? "protected" : "real");
 
    return ERROR_OK;
}
 
int lakemont_halt(struct target *t)
{
    if (t->state == TARGET_RUNNING) {
        t->debug_reason = DBG_REASON_DBGRQ;
        if (do_halt(t) != ERROR_OK)
            return ERROR_FAIL;
        return ERROR_OK;
    } else {
        LOG_ERROR("%s target not running", __func__);
        return ERROR_FAIL;
    }
}
 
int lakemont_resume(struct target *t, int current, target_addr_t address,
            int handle_breakpoints, int debug_execution)
{
    struct breakpoint *bp = NULL;
    struct x86_32_common *x86_32 = target_to_x86_32(t);
 
    if (check_not_halted(t))
        return ERROR_TARGET_NOT_HALTED;
    /* TODO lakemont_enable_breakpoints(t); */
    if (t->state == TARGET_HALTED) {
 
        /* running away for a software breakpoint needs some special handling */
        uint32_t eip = buf_get_u32(x86_32->cache->reg_list[EIP].value, 0, 32);
        bp = breakpoint_find(t, eip);
        if (bp /*&& bp->type == BKPT_SOFT*/) {
            /* the step will step over the breakpoint */
            if (lakemont_step(t, 0, 0, 1) != ERROR_OK) {
                LOG_ERROR("%s stepping over a software breakpoint at 0x%08" PRIx32 " "
                        "failed to resume the target", __func__, eip);
                return ERROR_FAIL;
            }
        }
 
        /* if breakpoints are enabled, we need to redirect these into probe mode */
        struct breakpoint *activeswbp = t->breakpoints;
        while (activeswbp && !activeswbp->is_set)
            activeswbp = activeswbp->next;
        struct watchpoint *activehwbp = t->watchpoints;
        while (activehwbp && !activehwbp->is_set)
            activehwbp = activehwbp->next;
        if (activeswbp || activehwbp)
            buf_set_u32(x86_32->cache->reg_list[PMCR].value, 0, 32, 1);
        if (do_resume(t) != ERROR_OK)
            return ERROR_FAIL;
    } else {
        LOG_USER("target not halted");
        return ERROR_FAIL;
    }
    return ERROR_OK;
}
 
int lakemont_step(struct target *t, int current,
            target_addr_t address, int handle_breakpoints)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    uint32_t eflags = buf_get_u32(x86_32->cache->reg_list[EFLAGS].value, 0, 32);
    uint32_t eip = buf_get_u32(x86_32->cache->reg_list[EIP].value, 0, 32);
    uint32_t pmcr = buf_get_u32(x86_32->cache->reg_list[PMCR].value, 0, 32);
    struct breakpoint *bp = NULL;
    int retval = ERROR_OK;
    uint32_t tapstatus = 0;
 
    if (check_not_halted(t))
        return ERROR_TARGET_NOT_HALTED;
    bp = breakpoint_find(t, eip);
    if (retval == ERROR_OK && bp/*&& bp->type == BKPT_SOFT*/) {
        /* TODO: This should only be done for software breakpoints.
         * Stepping from hardware breakpoints should be possible with the resume flag
         * Needs testing.
         */
        retval = x86_32_common_remove_breakpoint(t, bp);
    }
 
    /* Set EFLAGS[TF] and PMCR[IR], exit pm and wait for PRDY# */
    LOG_DEBUG("modifying PMCR = 0x%08" PRIx32 " and EFLAGS = 0x%08" PRIx32, pmcr, eflags);
    eflags = eflags | (EFLAGS_TF | EFLAGS_RF);
    buf_set_u32(x86_32->cache->reg_list[EFLAGS].value, 0, 32, eflags);
    buf_set_u32(x86_32->cache->reg_list[PMCR].value, 0, 32, 1);
    LOG_DEBUG("EFLAGS [TF] [RF] bits set=0x%08" PRIx32 ", PMCR=0x%08" PRIx32 ", EIP=0x%08" PRIx32,
            eflags, pmcr, eip);
 
    /* Returned value unused. Can this line be removed? */
    get_tapstatus(t);
 
    t->debug_reason = DBG_REASON_SINGLESTEP;
    t->state = TARGET_DEBUG_RUNNING;
    if (restore_context(t) != ERROR_OK)
        return ERROR_FAIL;
    if (exit_probemode(t) != ERROR_OK)
        return ERROR_FAIL;
 
    target_call_event_callbacks(t, TARGET_EVENT_RESUMED);
 
    tapstatus = get_tapstatus(t);
    if (tapstatus & (TS_PM_BIT | TS_EN_PM_BIT | TS_PRDY_BIT | TS_PMCR_BIT)) {
        /* target has stopped */
        if (save_context(t) != ERROR_OK)
            return ERROR_FAIL;
        if (halt_prep(t) != ERROR_OK)
            return ERROR_FAIL;
        t->state = TARGET_HALTED;
 
        LOG_USER("step done from EIP 0x%08" PRIx32 " to 0x%08" PRIx32, eip,
                buf_get_u32(x86_32->cache->reg_list[EIP].value, 0, 32));
        target_call_event_callbacks(t, TARGET_EVENT_HALTED);
    } else {
        /* target didn't stop
         * I hope the poll() will catch it, but the deleted breakpoint is gone
         */
        LOG_ERROR("%s target didn't stop after executing a single step", __func__);
        t->state = TARGET_RUNNING;
        return ERROR_FAIL;
    }
 
    /* try to re-apply the breakpoint, even of step failed
     * TODO: When a bp was set, we should try to stop the target - fix the return above
     */
    if (bp/*&& bp->type == BKPT_SOFT*/) {
        /* TODO: This should only be done for software breakpoints.
         * Stepping from hardware breakpoints should be possible with the resume flag
         * Needs testing.
         */
        retval = x86_32_common_add_breakpoint(t, bp);
    }
 
    return retval;
}
 
static int lakemont_reset_break(struct target *t)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    struct jtag_tap *saved_tap = x86_32->curr_tap;
    struct scan_field *fields = &scan.field;
 
    int retval = ERROR_OK;
 
    LOG_DEBUG("issuing port 0xcf9 reset");
 
    /* prepare resetbreak setting the proper bits in CLTAPC_CPU_VPREQ */
    x86_32->curr_tap = jtag_tap_by_position(1);
    if (!x86_32->curr_tap) {
        x86_32->curr_tap = saved_tap;
        LOG_ERROR("%s could not select quark_x10xx.cltap", __func__);
        return ERROR_FAIL;
    }
 
    fields->in_value  = NULL;
    fields->num_bits  = 8;
 
    /* select CLTAPC_CPU_VPREQ instruction*/
    scan.out[0] = 0x51;
    fields->out_value = ((uint8_t *)scan.out);
    jtag_add_ir_scan(x86_32->curr_tap, fields, TAP_IDLE);
    retval = jtag_execute_queue();
    if (retval != ERROR_OK) {
        x86_32->curr_tap = saved_tap;
        LOG_ERROR("%s irscan failed to execute queue", __func__);
        return retval;
    }
 
    /* set enable_preq_on_reset & enable_preq_on_reset2 bits*/
    scan.out[0] = 0x06;
    fields->out_value  = ((uint8_t *)scan.out);
    jtag_add_dr_scan(x86_32->curr_tap, 1, fields, TAP_IDLE);
    retval = jtag_execute_queue();
    if (retval != ERROR_OK) {
        LOG_ERROR("%s drscan failed to execute queue", __func__);
        x86_32->curr_tap = saved_tap;
        return retval;
    }
 
    /* restore current tap */
    x86_32->curr_tap = saved_tap;
 
    return ERROR_OK;
}
 
/*
 * If we ever get an adapter with support for PREQ# and PRDY#, we should
 * update this function to add support for using those two signals.
 *
 * Meanwhile, we're assuming that we only support reset break.
 */
int lakemont_reset_assert(struct target *t)
{
    struct x86_32_common *x86_32 = target_to_x86_32(t);
    /* write 0x6 to I/O port 0xcf9 to cause the reset */
    uint8_t cf9_reset_val = 0x6;
    int retval;
 
    LOG_DEBUG(" ");
 
    if (t->state != TARGET_HALTED) {
        LOG_DEBUG("target must be halted first");
        retval = lakemont_halt(t);
        if (retval != ERROR_OK) {
            LOG_ERROR("could not halt target");
            return retval;
        }
        x86_32->forced_halt_for_reset = true;
    }
 
    if (t->reset_halt) {
        retval = lakemont_reset_break(t);
        if (retval != ERROR_OK)
            return retval;
    }
 
    retval = x86_32_common_write_io(t, 0xcf9, BYTE, &cf9_reset_val);
    if (retval != ERROR_OK) {
        LOG_ERROR("could not write to port 0xcf9");
        return retval;
    }
 
    if (!t->reset_halt && x86_32->forced_halt_for_reset) {
        x86_32->forced_halt_for_reset = false;
        retval = lakemont_resume(t, true, 0x00, false, true);
        if (retval != ERROR_OK)
            return retval;
    }
 
    /* remove breakpoints and watchpoints */
    x86_32_common_reset_breakpoints_watchpoints(t);
 
    return ERROR_OK;
}
 
int lakemont_reset_deassert(struct target *t)
{
    int retval;
 
    LOG_DEBUG(" ");
 
    if (target_was_examined(t)) {
        retval = lakemont_poll(t);
        if (retval != ERROR_OK)
            return retval;
    }
 
    if (t->reset_halt) {
        /* entered PM after reset, update the state */
        retval = lakemont_update_after_probemode_entry(t);
        if (retval != ERROR_OK) {
            LOG_ERROR("could not update state after probemode entry");
            return retval;
        }
 
        if (t->state != TARGET_HALTED) {
            LOG_WARNING("%s: ran after reset and before halt ...",
                target_name(t));
            if (target_was_examined(t)) {
                retval = target_halt(t);
                if (retval != ERROR_OK)
                    return retval;
            } else {
                t->state = TARGET_UNKNOWN;
            }
        }
    }
 
    return ERROR_OK;
}