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openocd/src/target/armv8_dpm.c

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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2009 by David Brownell
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "arm.h"
#include "armv8.h"
#include "armv8_dpm.h"
#include <jtag/jtag.h>
#include "register.h"
#include "breakpoints.h"
#include "target_type.h"
#include "armv8_opcodes.h"
#include "helper/time_support.h"
/* T32 ITR format */
#define T32_FMTITR(instr) (((instr & 0x0000FFFF) << 16) | ((instr & 0xFFFF0000) >> 16))
/**
* @file
* Implements various ARM DPM operations using architectural debug registers.
* These routines layer over core-specific communication methods to cope with
* implementation differences between cores like ARM1136 and Cortex-A8.
*
* The "Debug Programmers' Model" (DPM) for ARMv6 and ARMv7 is defined by
* Part C (Debug Architecture) of the ARM Architecture Reference Manual,
* ARMv7-A and ARMv7-R edition (ARM DDI 0406B). In OpenOCD, DPM operations
* are abstracted through internal programming interfaces to share code and
* to minimize needless differences in debug behavior between cores.
*/
/**
* Get core state from EDSCR, without necessity to retrieve CPSR
*/
enum arm_state armv8_dpm_get_core_state(struct arm_dpm *dpm)
{
int el = (dpm->dscr >> 8) & 0x3;
int rw = (dpm->dscr >> 10) & 0xF;
dpm->last_el = el;
/* In Debug state, each bit gives the current Execution state of each EL */
if ((rw >> el) & 0b1)
return ARM_STATE_AARCH64;
return ARM_STATE_ARM;
}
/*----------------------------------------------------------------------*/
static int dpmv8_write_dcc(struct armv8_common *armv8, uint32_t data)
{
return mem_ap_write_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DTRRX, data);
}
static int dpmv8_write_dcc_64(struct armv8_common *armv8, uint64_t data)
{
int ret;
ret = mem_ap_write_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DTRRX, data);
if (ret == ERROR_OK)
ret = mem_ap_write_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DTRTX, data >> 32);
return ret;
}
static int dpmv8_read_dcc(struct armv8_common *armv8, uint32_t *data,
uint32_t *dscr_p)
{
uint32_t dscr = DSCR_ITE;
int retval;
if (dscr_p)
dscr = *dscr_p;
/* Wait for DTRRXfull */
long long then = timeval_ms();
while ((dscr & DSCR_DTR_TX_FULL) == 0) {
retval = mem_ap_read_atomic_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DSCR,
&dscr);
if (retval != ERROR_OK)
return retval;
if (timeval_ms() > then + 1000) {
LOG_ERROR("Timeout waiting for read dcc");
return ERROR_FAIL;
}
}
retval = mem_ap_read_atomic_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DTRTX,
data);
if (retval != ERROR_OK)
return retval;
if (dscr_p)
*dscr_p = dscr;
return retval;
}
static int dpmv8_read_dcc_64(struct armv8_common *armv8, uint64_t *data,
uint32_t *dscr_p)
{
uint32_t dscr = DSCR_ITE;
uint32_t higher;
int retval;
if (dscr_p)
dscr = *dscr_p;
/* Wait for DTRRXfull */
long long then = timeval_ms();
while ((dscr & DSCR_DTR_TX_FULL) == 0) {
retval = mem_ap_read_atomic_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DSCR,
&dscr);
if (retval != ERROR_OK)
return retval;
if (timeval_ms() > then + 1000) {
LOG_ERROR("Timeout waiting for DTR_TX_FULL, dscr = 0x%08" PRIx32, dscr);
return ERROR_FAIL;
}
}
retval = mem_ap_read_atomic_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DTRTX,
(uint32_t *)data);
if (retval != ERROR_OK)
return retval;
retval = mem_ap_read_atomic_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DTRRX,
&higher);
if (retval != ERROR_OK)
return retval;
*data = *(uint32_t *)data | (uint64_t)higher << 32;
if (dscr_p)
*dscr_p = dscr;
return retval;
}
static int dpmv8_dpm_prepare(struct arm_dpm *dpm)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
uint32_t dscr;
int retval;
/* set up invariant: ITE is set after ever DPM operation */
long long then = timeval_ms();
for (;; ) {
retval = mem_ap_read_atomic_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DSCR,
&dscr);
if (retval != ERROR_OK)
return retval;
if ((dscr & DSCR_ITE) != 0)
break;
if (timeval_ms() > then + 1000) {
LOG_ERROR("Timeout waiting for dpm prepare");
return ERROR_FAIL;
}
}
/* update the stored copy of dscr */
dpm->dscr = dscr;
/* this "should never happen" ... */
if (dscr & DSCR_DTR_RX_FULL) {
LOG_ERROR("DSCR_DTR_RX_FULL, dscr 0x%08" PRIx32, dscr);
/* Clear DCCRX */
retval = mem_ap_read_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DTRRX, &dscr);
if (retval != ERROR_OK)
return retval;
}
return retval;
}
static int dpmv8_dpm_finish(struct arm_dpm *dpm)
{
/* REVISIT what could be done here? */
return ERROR_OK;
}
static int dpmv8_exec_opcode(struct arm_dpm *dpm,
uint32_t opcode, uint32_t *p_dscr)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
uint32_t dscr = dpm->dscr;
int retval;
if (p_dscr)
dscr = *p_dscr;
/* Wait for InstrCompl bit to be set */
long long then = timeval_ms();
while ((dscr & DSCR_ITE) == 0) {
retval = mem_ap_read_atomic_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DSCR, &dscr);
if (retval != ERROR_OK) {
LOG_ERROR("Could not read DSCR register, opcode = 0x%08" PRIx32, opcode);
return retval;
}
if (timeval_ms() > then + 1000) {
LOG_ERROR("Timeout waiting for aarch64_exec_opcode");
return ERROR_FAIL;
}
}
if (armv8_dpm_get_core_state(dpm) != ARM_STATE_AARCH64)
opcode = T32_FMTITR(opcode);
retval = mem_ap_write_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_ITR, opcode);
if (retval != ERROR_OK)
return retval;
then = timeval_ms();
do {
retval = mem_ap_read_atomic_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DSCR, &dscr);
if (retval != ERROR_OK) {
LOG_ERROR("Could not read DSCR register");
return retval;
}
if (timeval_ms() > then + 1000) {
LOG_ERROR("Timeout waiting for aarch64_exec_opcode");
return ERROR_FAIL;
}
} while ((dscr & DSCR_ITE) == 0); /* Wait for InstrCompl bit to be set */
/* update dscr and el after each command execution */
dpm->dscr = dscr;
if (dpm->last_el != ((dscr >> 8) & 3))
LOG_DEBUG("EL %i -> %" PRIu32, dpm->last_el, (dscr >> 8) & 3);
dpm->last_el = (dscr >> 8) & 3;
if (dscr & DSCR_ERR) {
LOG_ERROR("Opcode 0x%08" PRIx32 ", DSCR.ERR=1, DSCR.EL=%i", opcode, dpm->last_el);
armv8_dpm_handle_exception(dpm, true);
retval = ERROR_FAIL;
}
if (p_dscr)
*p_dscr = dscr;
return retval;
}
static int dpmv8_instr_execute(struct arm_dpm *dpm, uint32_t opcode)
{
return dpmv8_exec_opcode(dpm, opcode, NULL);
}
static int dpmv8_instr_write_data_dcc(struct arm_dpm *dpm,
uint32_t opcode, uint32_t data)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
int retval;
retval = dpmv8_write_dcc(armv8, data);
if (retval != ERROR_OK)
return retval;
return dpmv8_exec_opcode(dpm, opcode, 0);
}
static int dpmv8_instr_write_data_dcc_64(struct arm_dpm *dpm,
uint32_t opcode, uint64_t data)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
int retval;
retval = dpmv8_write_dcc_64(armv8, data);
if (retval != ERROR_OK)
return retval;
return dpmv8_exec_opcode(dpm, opcode, 0);
}
static int dpmv8_instr_write_data_r0(struct arm_dpm *dpm,
uint32_t opcode, uint32_t data)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
uint32_t dscr = DSCR_ITE;
int retval;
retval = dpmv8_write_dcc(armv8, data);
if (retval != ERROR_OK)
return retval;
retval = dpmv8_exec_opcode(dpm, armv8_opcode(armv8, READ_REG_DTRRX), &dscr);
if (retval != ERROR_OK)
return retval;
/* then the opcode, taking data from R0 */
return dpmv8_exec_opcode(dpm, opcode, &dscr);
}
static int dpmv8_instr_write_data_r0_64(struct arm_dpm *dpm,
uint32_t opcode, uint64_t data)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
int retval;
if (dpm->arm->core_state != ARM_STATE_AARCH64)
return dpmv8_instr_write_data_r0(dpm, opcode, data);
/* transfer data from DCC to R0 */
retval = dpmv8_write_dcc_64(armv8, data);
if (retval == ERROR_OK)
retval = dpmv8_exec_opcode(dpm, ARMV8_MRS(SYSTEM_DBG_DBGDTR_EL0, 0), &dpm->dscr);
/* then the opcode, taking data from R0 */
if (retval == ERROR_OK)
retval = dpmv8_exec_opcode(dpm, opcode, &dpm->dscr);
return retval;
}
static int dpmv8_instr_cpsr_sync(struct arm_dpm *dpm)
{
int retval;
struct armv8_common *armv8 = dpm->arm->arch_info;
/* "Prefetch flush" after modifying execution status in CPSR */
retval = dpmv8_exec_opcode(dpm, armv8_opcode(armv8, ARMV8_OPC_DSB_SY), &dpm->dscr);
if (retval == ERROR_OK)
dpmv8_exec_opcode(dpm, armv8_opcode(armv8, ARMV8_OPC_ISB_SY), &dpm->dscr);
return retval;
}
static int dpmv8_instr_read_data_dcc(struct arm_dpm *dpm,
uint32_t opcode, uint32_t *data)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
int retval;
/* the opcode, writing data to DCC */
retval = dpmv8_exec_opcode(dpm, opcode, &dpm->dscr);
if (retval != ERROR_OK)
return retval;
return dpmv8_read_dcc(armv8, data, &dpm->dscr);
}
static int dpmv8_instr_read_data_dcc_64(struct arm_dpm *dpm,
uint32_t opcode, uint64_t *data)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
int retval;
/* the opcode, writing data to DCC */
retval = dpmv8_exec_opcode(dpm, opcode, &dpm->dscr);
if (retval != ERROR_OK)
return retval;
return dpmv8_read_dcc_64(armv8, data, &dpm->dscr);
}
static int dpmv8_instr_read_data_r0(struct arm_dpm *dpm,
uint32_t opcode, uint32_t *data)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
int retval;
/* the opcode, writing data to R0 */
retval = dpmv8_exec_opcode(dpm, opcode, &dpm->dscr);
if (retval != ERROR_OK)
return retval;
/* write R0 to DCC */
retval = dpmv8_exec_opcode(dpm, armv8_opcode(armv8, WRITE_REG_DTRTX), &dpm->dscr);
if (retval != ERROR_OK)
return retval;
return dpmv8_read_dcc(armv8, data, &dpm->dscr);
}
static int dpmv8_instr_read_data_r0_64(struct arm_dpm *dpm,
uint32_t opcode, uint64_t *data)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
int retval;
if (dpm->arm->core_state != ARM_STATE_AARCH64) {
uint32_t tmp;
retval = dpmv8_instr_read_data_r0(dpm, opcode, &tmp);
if (retval == ERROR_OK)
*data = tmp;
return retval;
}
/* the opcode, writing data to R0 */
retval = dpmv8_exec_opcode(dpm, opcode, &dpm->dscr);
if (retval != ERROR_OK)
return retval;
/* write R0 to DCC */
retval = dpmv8_exec_opcode(dpm, ARMV8_MSR_GP(SYSTEM_DBG_DBGDTR_EL0, 0), &dpm->dscr);
if (retval != ERROR_OK)
return retval;
return dpmv8_read_dcc_64(armv8, data, &dpm->dscr);
}
#if 0
static int dpmv8_bpwp_enable(struct arm_dpm *dpm, unsigned index_t,
target_addr_t addr, uint32_t control)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
uint32_t vr = armv8->debug_base;
uint32_t cr = armv8->debug_base;
int retval;
switch (index_t) {
case 0 ... 15: /* breakpoints */
vr += CPUV8_DBG_BVR_BASE;
cr += CPUV8_DBG_BCR_BASE;
break;
case 16 ... 31: /* watchpoints */
vr += CPUV8_DBG_WVR_BASE;
cr += CPUV8_DBG_WCR_BASE;
index_t -= 16;
break;
default:
return ERROR_FAIL;
}
vr += 16 * index_t;
cr += 16 * index_t;
LOG_DEBUG("A8: bpwp enable, vr %08x cr %08x",
(unsigned) vr, (unsigned) cr);
retval = mem_ap_write_atomic_u32(armv8->debug_ap, vr, addr);
if (retval != ERROR_OK)
return retval;
return mem_ap_write_atomic_u32(armv8->debug_ap, cr, control);
}
#endif
static int dpmv8_bpwp_disable(struct arm_dpm *dpm, unsigned index_t)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
uint32_t cr;
switch (index_t) {
case 0 ... 15:
cr = armv8->debug_base + CPUV8_DBG_BCR_BASE;
break;
case 16 ... 31:
cr = armv8->debug_base + CPUV8_DBG_WCR_BASE;
index_t -= 16;
break;
default:
return ERROR_FAIL;
}
cr += 16 * index_t;
LOG_DEBUG("A: bpwp disable, cr %08x", (unsigned) cr);
/* clear control register */
return mem_ap_write_atomic_u32(armv8->debug_ap, cr, 0);
}
/*
* Coprocessor support
*/
/* Read coprocessor */
static int dpmv8_mrc(struct target *target, int cpnum,
uint32_t op1, uint32_t op2, uint32_t crn, uint32_t crm,
uint32_t *value)
{
struct arm *arm = target_to_arm(target);
struct arm_dpm *dpm = arm->dpm;
int retval;
retval = dpm->prepare(dpm);
if (retval != ERROR_OK)
return retval;
LOG_DEBUG("MRC p%d, %d, r0, c%d, c%d, %d", cpnum,
(int) op1, (int) crn,
(int) crm, (int) op2);
/* read coprocessor register into R0; return via DCC */
retval = dpm->instr_read_data_r0(dpm,
ARMV4_5_MRC(cpnum, op1, 0, crn, crm, op2),
value);
/* (void) */ dpm->finish(dpm);
return retval;
}
static int dpmv8_mcr(struct target *target, int cpnum,
uint32_t op1, uint32_t op2, uint32_t crn, uint32_t crm,
uint32_t value)
{
struct arm *arm = target_to_arm(target);
struct arm_dpm *dpm = arm->dpm;
int retval;
retval = dpm->prepare(dpm);
if (retval != ERROR_OK)
return retval;
LOG_DEBUG("MCR p%d, %d, r0, c%d, c%d, %d", cpnum,
(int) op1, (int) crn,
(int) crm, (int) op2);
/* read DCC into r0; then write coprocessor register from R0 */
retval = dpm->instr_write_data_r0(dpm,
ARMV4_5_MCR(cpnum, op1, 0, crn, crm, op2),
value);
/* (void) */ dpm->finish(dpm);
return retval;
}
/*----------------------------------------------------------------------*/
/*
* Register access utilities
*/
int armv8_dpm_modeswitch(struct arm_dpm *dpm, enum arm_mode mode)
{
struct armv8_common *armv8 = (struct armv8_common *)dpm->arm->arch_info;
int retval = ERROR_OK;
unsigned int target_el;
enum arm_state core_state;
uint32_t cpsr;
/* restore previous mode */
if (mode == ARM_MODE_ANY) {
cpsr = buf_get_u32(dpm->arm->cpsr->value, 0, 32);
LOG_DEBUG("restoring mode, cpsr = 0x%08"PRIx32, cpsr);
} else {
LOG_DEBUG("setting mode 0x%x", mode);
cpsr = mode;
}
switch (cpsr & 0x1f) {
/* aarch32 modes */
case ARM_MODE_USR:
target_el = 0;
break;
case ARM_MODE_SVC:
case ARM_MODE_ABT:
case ARM_MODE_IRQ:
case ARM_MODE_FIQ:
case ARM_MODE_SYS:
target_el = 1;
break;
/*
* TODO: handle ARM_MODE_HYP
* case ARM_MODE_HYP:
* target_el = 2;
* break;
*/
case ARM_MODE_MON:
target_el = 3;
break;
/* aarch64 modes */
default:
target_el = (cpsr >> 2) & 3;
}
if (target_el > SYSTEM_CUREL_EL3) {
LOG_ERROR("%s: Invalid target exception level %i", __func__, target_el);
return ERROR_FAIL;
}
LOG_DEBUG("target_el = %i, last_el = %i", target_el, dpm->last_el);
if (target_el > dpm->last_el) {
retval = dpm->instr_execute(dpm,
armv8_opcode(armv8, ARMV8_OPC_DCPS) | target_el);
/* DCPS clobbers registers just like an exception taken */
armv8_dpm_handle_exception(dpm, false);
} else {
core_state = armv8_dpm_get_core_state(dpm);
if (core_state != ARM_STATE_AARCH64) {
/* cannot do DRPS/ERET when already in EL0 */
if (dpm->last_el != 0) {
/* load SPSR with the desired mode and execute DRPS */
LOG_DEBUG("SPSR = 0x%08"PRIx32, cpsr);
retval = dpm->instr_write_data_r0(dpm,
ARMV8_MSR_GP_xPSR_T1(1, 0, 15), cpsr);
if (retval == ERROR_OK)
retval = dpm->instr_execute(dpm, armv8_opcode(armv8, ARMV8_OPC_DRPS));
}
} else {
/*
* need to execute multiple DRPS instructions until target_el
* is reached
*/
while (retval == ERROR_OK && dpm->last_el != target_el) {
unsigned int cur_el = dpm->last_el;
retval = dpm->instr_execute(dpm, armv8_opcode(armv8, ARMV8_OPC_DRPS));
if (cur_el == dpm->last_el) {
LOG_INFO("Cannot reach EL %i, SPSR corrupted?", target_el);
break;
}
}
}
/* On executing DRPS, DSPSR and DLR become UNKNOWN, mark them as dirty */
dpm->arm->cpsr->dirty = true;
dpm->arm->pc->dirty = true;
/*
* re-evaluate the core state, we might be in Aarch32 state now
* we rely on dpm->dscr being up-to-date
*/
core_state = armv8_dpm_get_core_state(dpm);
armv8_select_opcodes(armv8, core_state == ARM_STATE_AARCH64);
armv8_select_reg_access(armv8, core_state == ARM_STATE_AARCH64);
}
return retval;
}
/*
* Common register read, relies on armv8_select_reg_access() having been called.
*/
static int dpmv8_read_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
int retval = ERROR_FAIL;
if (r->size <= 64) {
uint64_t value_64;
retval = armv8->read_reg_u64(armv8, regnum, &value_64);
if (retval == ERROR_OK) {
r->valid = true;
r->dirty = false;
buf_set_u64(r->value, 0, r->size, value_64);
if (r->size == 64)
LOG_DEBUG("READ: %s, %16.8llx", r->name, (unsigned long long) value_64);
else
LOG_DEBUG("READ: %s, %8.8x", r->name, (unsigned int) value_64);
}
} else if (r->size <= 128) {
uint64_t lvalue = 0, hvalue = 0;
retval = armv8->read_reg_u128(armv8, regnum, &lvalue, &hvalue);
if (retval == ERROR_OK) {
r->valid = true;
r->dirty = false;
buf_set_u64(r->value, 0, 64, lvalue);
buf_set_u64(r->value + 8, 0, r->size - 64, hvalue);
LOG_DEBUG("READ: %s, lvalue=%16.8llx", r->name, (unsigned long long) lvalue);
LOG_DEBUG("READ: %s, hvalue=%16.8llx", r->name, (unsigned long long) hvalue);
}
}
if (retval != ERROR_OK)
LOG_ERROR("Failed to read %s register", r->name);
return retval;
}
/*
* Common register write, relies on armv8_select_reg_access() having been called.
*/
static int dpmv8_write_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
int retval = ERROR_FAIL;
if (r->size <= 64) {
uint64_t value_64;
value_64 = buf_get_u64(r->value, 0, r->size);
retval = armv8->write_reg_u64(armv8, regnum, value_64);
if (retval == ERROR_OK) {
r->dirty = false;
if (r->size == 64)
LOG_DEBUG("WRITE: %s, %16.8llx", r->name, (unsigned long long)value_64);
else
LOG_DEBUG("WRITE: %s, %8.8x", r->name, (unsigned int)value_64);
}
} else if (r->size <= 128) {
uint64_t lvalue, hvalue;
lvalue = buf_get_u64(r->value, 0, 64);
hvalue = buf_get_u64(r->value + 8, 0, r->size - 64);
retval = armv8->write_reg_u128(armv8, regnum, lvalue, hvalue);
if (retval == ERROR_OK) {
r->dirty = false;
LOG_DEBUG("WRITE: %s, lvalue=%16.8llx", r->name, (unsigned long long) lvalue);
LOG_DEBUG("WRITE: %s, hvalue=%16.8llx", r->name, (unsigned long long) hvalue);
}
}
if (retval != ERROR_OK)
LOG_ERROR("Failed to write %s register", r->name);
return retval;
}
/**
* Read basic registers of the current context: R0 to R15, and CPSR;
* sets the core mode (such as USR or IRQ) and state (such as ARM or Thumb).
* In normal operation this is called on entry to halting debug state,
* possibly after some other operations supporting restore of debug state
* or making sure the CPU is fully idle (drain write buffer, etc).
*/
int armv8_dpm_read_current_registers(struct arm_dpm *dpm)
{
struct arm *arm = dpm->arm;
struct armv8_common *armv8 = (struct armv8_common *)arm->arch_info;
struct reg_cache *cache;
struct reg *r;
uint32_t cpsr;
int retval;
retval = dpm->prepare(dpm);
if (retval != ERROR_OK)
return retval;
cache = arm->core_cache;
/* read R0 first (it's used for scratch), then CPSR */
r = cache->reg_list + ARMV8_R0;
if (!r->valid) {
retval = dpmv8_read_reg(dpm, r, ARMV8_R0);
if (retval != ERROR_OK)
goto fail;
}
r->dirty = true;
/* read R1, too, it will be clobbered during memory access */
r = cache->reg_list + ARMV8_R1;
if (!r->valid) {
retval = dpmv8_read_reg(dpm, r, ARMV8_R1);
if (retval != ERROR_OK)
goto fail;
}
/* read cpsr to r0 and get it back */
retval = dpm->instr_read_data_r0(dpm,
armv8_opcode(armv8, READ_REG_DSPSR), &cpsr);
if (retval != ERROR_OK)
goto fail;
/* update core mode and state */
armv8_set_cpsr(arm, cpsr);
for (unsigned int i = ARMV8_PC; i < cache->num_regs ; i++) {
struct arm_reg *arm_reg;
r = armv8_reg_current(arm, i);
if (!r->exist || r->valid)
continue;
/* Skip reading FP-SIMD registers */
if (r->number >= ARMV8_V0 && r->number <= ARMV8_FPCR)
continue;
/*
* Only read registers that are available from the
* current EL (or core mode).
*/
arm_reg = r->arch_info;
if (arm_reg->mode != ARM_MODE_ANY &&
dpm->last_el != armv8_curel_from_core_mode(arm_reg->mode))
continue;
/* Special case: ARM_MODE_SYS has no SPSR at EL1 */
if (r->number == ARMV8_SPSR_EL1 && arm->core_mode == ARM_MODE_SYS)
continue;
retval = dpmv8_read_reg(dpm, r, i);
if (retval != ERROR_OK)
goto fail;
}
fail:
dpm->finish(dpm);
return retval;
}
/* Avoid needless I/O ... leave breakpoints and watchpoints alone
* unless they're removed, or need updating because of single-stepping
* or running debugger code.
*/
static int dpmv8_maybe_update_bpwp(struct arm_dpm *dpm, bool bpwp,
struct dpm_bpwp *xp, bool *set_p)
{
int retval = ERROR_OK;
bool disable;
if (!set_p) {
if (!xp->dirty)
goto done;
xp->dirty = false;
/* removed or startup; we must disable it */
disable = true;
} else if (bpwp) {
if (!xp->dirty)
goto done;
/* disabled, but we must set it */
xp->dirty = disable = false;
*set_p = true;
} else {
if (!*set_p)
goto done;
/* set, but we must temporarily disable it */
xp->dirty = disable = true;
*set_p = false;
}
if (disable)
retval = dpm->bpwp_disable(dpm, xp->number);
else
retval = dpm->bpwp_enable(dpm, xp->number,
xp->address, xp->control);
if (retval != ERROR_OK)
LOG_ERROR("%s: can't %s HW %spoint %d",
disable ? "disable" : "enable",
target_name(dpm->arm->target),
(xp->number < 16) ? "break" : "watch",
xp->number & 0xf);
done:
return retval;
}
static int dpmv8_add_breakpoint(struct target *target, struct breakpoint *bp);
/**
* Writes all modified core registers for all processor modes. In normal
* operation this is called on exit from halting debug state.
*
* @param dpm: represents the processor
* @param bpwp: true ensures breakpoints and watchpoints are set,
* false ensures they are cleared
*/
int armv8_dpm_write_dirty_registers(struct arm_dpm *dpm, bool bpwp)
{
struct arm *arm = dpm->arm;
struct reg_cache *cache = arm->core_cache;
int retval;
retval = dpm->prepare(dpm);
if (retval != ERROR_OK)
goto done;
/* If we're managing hardware breakpoints for this core, enable
* or disable them as requested.
*
* REVISIT We don't yet manage them for ANY cores. Eventually
* we should be able to assume we handle them; but until then,
* cope with the hand-crafted breakpoint code.
*/
if (arm->target->type->add_breakpoint == dpmv8_add_breakpoint) {
for (unsigned i = 0; i < dpm->nbp; i++) {
struct dpm_bp *dbp = dpm->dbp + i;
struct breakpoint *bp = dbp->bp;
retval = dpmv8_maybe_update_bpwp(dpm, bpwp, &dbp->bpwp,
bp ? &bp->is_set : NULL);
if (retval != ERROR_OK)
goto done;
}
}
/* enable/disable watchpoints */
for (unsigned i = 0; i < dpm->nwp; i++) {
struct dpm_wp *dwp = dpm->dwp + i;
struct watchpoint *wp = dwp->wp;
retval = dpmv8_maybe_update_bpwp(dpm, bpwp, &dwp->bpwp,
wp ? &wp->is_set : NULL);
if (retval != ERROR_OK)
goto done;
}
/* NOTE: writes to breakpoint and watchpoint registers might
* be queued, and need (efficient/batched) flushing later.
*/
/* Restore original core mode and state */
retval = armv8_dpm_modeswitch(dpm, ARM_MODE_ANY);
if (retval != ERROR_OK)
goto done;
/* check everything except our scratch register R0 */
for (unsigned i = 1; i < cache->num_regs; i++) {
struct arm_reg *r;
/* skip non-existent */
if (!cache->reg_list[i].exist)
continue;
/* skip PC and CPSR */
if (i == ARMV8_PC || i == ARMV8_xPSR)
continue;
/* skip invalid */
if (!cache->reg_list[i].valid)
continue;
/* skip non-dirty */
if (!cache->reg_list[i].dirty)
continue;
/* skip all registers not on the current EL */
r = cache->reg_list[i].arch_info;
if (r->mode != ARM_MODE_ANY &&
dpm->last_el != armv8_curel_from_core_mode(r->mode))
continue;
retval = dpmv8_write_reg(dpm, &cache->reg_list[i], i);
if (retval != ERROR_OK)
break;
}
/* flush CPSR and PC */
if (retval == ERROR_OK)
retval = dpmv8_write_reg(dpm, &cache->reg_list[ARMV8_xPSR], ARMV8_xPSR);
if (retval == ERROR_OK)
retval = dpmv8_write_reg(dpm, &cache->reg_list[ARMV8_PC], ARMV8_PC);
/* flush R0 -- it's *very* dirty by now */
if (retval == ERROR_OK)
retval = dpmv8_write_reg(dpm, &cache->reg_list[0], 0);
if (retval == ERROR_OK)
dpm->instr_cpsr_sync(dpm);
done:
dpm->finish(dpm);
return retval;
}
/*
* Standard ARM register accessors ... there are three methods
* in "struct arm", to support individual read/write and bulk read
* of registers.
*/
static int armv8_dpm_read_core_reg(struct target *target, struct reg *r,
int regnum, enum arm_mode mode)
{
struct arm *arm = target_to_arm(target);
struct arm_dpm *dpm = target_to_arm(target)->dpm;
int retval;
int max = arm->core_cache->num_regs;
if (regnum < 0 || regnum >= max)
return ERROR_COMMAND_SYNTAX_ERROR;
/*
* REVISIT what happens if we try to read SPSR in a core mode
* which has no such register?
*/
retval = dpm->prepare(dpm);
if (retval != ERROR_OK)
return retval;
retval = dpmv8_read_reg(dpm, r, regnum);
if (retval != ERROR_OK)
goto fail;
fail:
/* (void) */ dpm->finish(dpm);
return retval;
}
static int armv8_dpm_write_core_reg(struct target *target, struct reg *r,
int regnum, enum arm_mode mode, uint8_t *value)
{
struct arm *arm = target_to_arm(target);
struct arm_dpm *dpm = target_to_arm(target)->dpm;
int retval;
int max = arm->core_cache->num_regs;
if (regnum < 0 || regnum > max)
return ERROR_COMMAND_SYNTAX_ERROR;
/* REVISIT what happens if we try to write SPSR in a core mode
* which has no such register?
*/
retval = dpm->prepare(dpm);
if (retval != ERROR_OK)
return retval;
retval = dpmv8_write_reg(dpm, r, regnum);
/* always clean up, regardless of error */
dpm->finish(dpm);
return retval;
}
static int armv8_dpm_full_context(struct target *target)
{
struct arm *arm = target_to_arm(target);
struct arm_dpm *dpm = arm->dpm;
struct reg_cache *cache = arm->core_cache;
int retval;
bool did_read;
retval = dpm->prepare(dpm);
if (retval != ERROR_OK)
goto done;
do {
enum arm_mode mode = ARM_MODE_ANY;
did_read = false;
/* We "know" arm_dpm_read_current_registers() was called so
* the unmapped registers (R0..R7, PC, AND CPSR) and some
* view of R8..R14 are current. We also "know" oddities of
* register mapping: special cases for R8..R12 and SPSR.
*
* Pick some mode with unread registers and read them all.
* Repeat until done.
*/
for (unsigned i = 0; i < cache->num_regs; i++) {
struct arm_reg *r;
if (!cache->reg_list[i].exist || cache->reg_list[i].valid)
continue;
r = cache->reg_list[i].arch_info;
/* may need to pick a mode and set CPSR */
if (!did_read) {
did_read = true;
mode = r->mode;
/* For regular (ARM_MODE_ANY) R8..R12
* in case we've entered debug state
* in FIQ mode we need to patch mode.
*/
if (mode != ARM_MODE_ANY)
retval = armv8_dpm_modeswitch(dpm, mode);
else
retval = armv8_dpm_modeswitch(dpm, ARM_MODE_USR);
if (retval != ERROR_OK)
goto done;
}
if (r->mode != mode)
continue;
/* CPSR was read, so "R16" must mean SPSR */
retval = dpmv8_read_reg(dpm,
&cache->reg_list[i],
(r->num == 16) ? 17 : r->num);
if (retval != ERROR_OK)
goto done;
}
} while (did_read);
retval = armv8_dpm_modeswitch(dpm, ARM_MODE_ANY);
/* (void) */ dpm->finish(dpm);
done:
return retval;
}
/*----------------------------------------------------------------------*/
/*
* Breakpoint and Watchpoint support.
*
* Hardware {break,watch}points are usually left active, to minimize
* debug entry/exit costs. When they are set or cleared, it's done in
* batches. Also, DPM-conformant hardware can update debug registers
* regardless of whether the CPU is running or halted ... though that
* fact isn't currently leveraged.
*/
static int dpmv8_bpwp_setup(struct arm_dpm *dpm, struct dpm_bpwp *xp,
uint32_t addr, uint32_t length)
{
uint32_t control;
control = (1 << 0) /* enable */
| (3 << 1); /* both user and privileged access */
/* Match 1, 2, or all 4 byte addresses in this word.
*
* FIXME: v7 hardware allows lengths up to 2 GB for BP and WP.
* Support larger length, when addr is suitably aligned. In
* particular, allow watchpoints on 8 byte "double" values.
*
* REVISIT allow watchpoints on unaligned 2-bit values; and on
* v7 hardware, unaligned 4-byte ones too.
*/
switch (length) {
case 1:
control |= (1 << (addr & 3)) << 5;
break;
case 2:
/* require 2-byte alignment */
if (!(addr & 1)) {
control |= (3 << (addr & 2)) << 5;
break;
}
/* FALL THROUGH */
case 4:
/* require 4-byte alignment */
if (!(addr & 3)) {
control |= 0xf << 5;
break;
}
/* FALL THROUGH */
default:
LOG_ERROR("unsupported {break,watch}point length/alignment");
return ERROR_COMMAND_SYNTAX_ERROR;
}
/* other shared control bits:
* bits 15:14 == 0 ... both secure and nonsecure states (v6.1+ only)
* bit 20 == 0 ... not linked to a context ID
* bit 28:24 == 0 ... not ignoring N LSBs (v7 only)
*/
xp->address = addr & ~3;
xp->control = control;
xp->dirty = true;
LOG_DEBUG("BPWP: addr %8.8" PRIx32 ", control %" PRIx32 ", number %d",
xp->address, control, xp->number);
/* hardware is updated in write_dirty_registers() */
return ERROR_OK;
}
static int dpmv8_add_breakpoint(struct target *target, struct breakpoint *bp)
{
struct arm *arm = target_to_arm(target);
struct arm_dpm *dpm = arm->dpm;
int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
if (bp->length < 2)
return ERROR_COMMAND_SYNTAX_ERROR;
if (!dpm->bpwp_enable)
return retval;
/* FIXME we need a generic solution for software breakpoints. */
if (bp->type == BKPT_SOFT)
LOG_DEBUG("using HW bkpt, not SW...");
for (unsigned i = 0; i < dpm->nbp; i++) {
if (!dpm->dbp[i].bp) {
retval = dpmv8_bpwp_setup(dpm, &dpm->dbp[i].bpwp,
bp->address, bp->length);
if (retval == ERROR_OK)
dpm->dbp[i].bp = bp;
break;
}
}
return retval;
}
static int dpmv8_remove_breakpoint(struct target *target, struct breakpoint *bp)
{
struct arm *arm = target_to_arm(target);
struct arm_dpm *dpm = arm->dpm;
int retval = ERROR_COMMAND_SYNTAX_ERROR;
for (unsigned i = 0; i < dpm->nbp; i++) {
if (dpm->dbp[i].bp == bp) {
dpm->dbp[i].bp = NULL;
dpm->dbp[i].bpwp.dirty = true;
/* hardware is updated in write_dirty_registers() */
retval = ERROR_OK;
break;
}
}
return retval;
}
static int dpmv8_watchpoint_setup(struct arm_dpm *dpm, unsigned index_t,
struct watchpoint *wp)
{
int retval;
struct dpm_wp *dwp = dpm->dwp + index_t;
uint32_t control;
/* this hardware doesn't support data value matching or masking */
if (wp->value || wp->mask != ~(uint32_t)0) {
LOG_DEBUG("watchpoint values and masking not supported");
return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
}
retval = dpmv8_bpwp_setup(dpm, &dwp->bpwp, wp->address, wp->length);
if (retval != ERROR_OK)
return retval;
control = dwp->bpwp.control;
switch (wp->rw) {
case WPT_READ:
control |= 1 << 3;
break;
case WPT_WRITE:
control |= 2 << 3;
break;
case WPT_ACCESS:
control |= 3 << 3;
break;
}
dwp->bpwp.control = control;
dpm->dwp[index_t].wp = wp;
return retval;
}
static int dpmv8_add_watchpoint(struct target *target, struct watchpoint *wp)
{
struct arm *arm = target_to_arm(target);
struct arm_dpm *dpm = arm->dpm;
int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
if (dpm->bpwp_enable) {
for (unsigned i = 0; i < dpm->nwp; i++) {
if (!dpm->dwp[i].wp) {
retval = dpmv8_watchpoint_setup(dpm, i, wp);
break;
}
}
}
return retval;
}
static int dpmv8_remove_watchpoint(struct target *target, struct watchpoint *wp)
{
struct arm *arm = target_to_arm(target);
struct arm_dpm *dpm = arm->dpm;
int retval = ERROR_COMMAND_SYNTAX_ERROR;
for (unsigned i = 0; i < dpm->nwp; i++) {
if (dpm->dwp[i].wp == wp) {
dpm->dwp[i].wp = NULL;
dpm->dwp[i].bpwp.dirty = true;
/* hardware is updated in write_dirty_registers() */
retval = ERROR_OK;
break;
}
}
return retval;
}
/*
* Handle exceptions taken in debug state. This happens mostly for memory
* accesses that violated a MMU policy. Taking an exception while in debug
* state clobbers certain state registers on the target exception level.
* Just mark those registers dirty so that they get restored on resume.
* This works both for Aarch32 and Aarch64 states.
*
* This function must not perform any actions that trigger another exception
* or a recursion will happen.
*/
void armv8_dpm_handle_exception(struct arm_dpm *dpm, bool do_restore)
{
struct armv8_common *armv8 = dpm->arm->arch_info;
struct reg_cache *cache = dpm->arm->core_cache;
enum arm_state core_state;
uint64_t dlr;
uint32_t dspsr;
unsigned int el;
static const int clobbered_regs_by_el[3][5] = {
{ ARMV8_PC, ARMV8_xPSR, ARMV8_ELR_EL1, ARMV8_ESR_EL1, ARMV8_SPSR_EL1 },
{ ARMV8_PC, ARMV8_xPSR, ARMV8_ELR_EL2, ARMV8_ESR_EL2, ARMV8_SPSR_EL2 },
{ ARMV8_PC, ARMV8_xPSR, ARMV8_ELR_EL3, ARMV8_ESR_EL3, ARMV8_SPSR_EL3 },
};
el = (dpm->dscr >> 8) & 3;
/* safety check, must not happen since EL0 cannot be a target for an exception */
if (el < SYSTEM_CUREL_EL1 || el > SYSTEM_CUREL_EL3) {
LOG_ERROR("%s: EL %i is invalid, DSCR corrupted?", __func__, el);
return;
}
/* Clear sticky error */
mem_ap_write_u32(armv8->debug_ap,
armv8->debug_base + CPUV8_DBG_DRCR, DRCR_CSE);
armv8->read_reg_u64(armv8, ARMV8_xPSR, &dlr);
dspsr = dlr;
armv8->read_reg_u64(armv8, ARMV8_PC, &dlr);
LOG_DEBUG("Exception taken to EL %i, DLR=0x%016"PRIx64" DSPSR=0x%08"PRIx32,
el, dlr, dspsr);
/* mark all clobbered registers as dirty */
for (int i = 0; i < 5; i++)
cache->reg_list[clobbered_regs_by_el[el-1][i]].dirty = true;
/*
* re-evaluate the core state, we might be in Aarch64 state now
* we rely on dpm->dscr being up-to-date
*/
core_state = armv8_dpm_get_core_state(dpm);
armv8_select_opcodes(armv8, core_state == ARM_STATE_AARCH64);
armv8_select_reg_access(armv8, core_state == ARM_STATE_AARCH64);
if (do_restore)
armv8_dpm_modeswitch(dpm, ARM_MODE_ANY);
}
/*----------------------------------------------------------------------*/
/*
* Other debug and support utilities
*/
void armv8_dpm_report_dscr(struct arm_dpm *dpm, uint32_t dscr)
{
struct target *target = dpm->arm->target;
dpm->dscr = dscr;
dpm->last_el = (dscr >> 8) & 3;
/* Examine debug reason */
switch (DSCR_ENTRY(dscr)) {
/* FALL THROUGH -- assume a v6 core in abort mode */
case DSCRV8_ENTRY_EXT_DEBUG: /* EDBGRQ */
target->debug_reason = DBG_REASON_DBGRQ;
break;
case DSCRV8_ENTRY_HALT_STEP_EXECLU: /* HALT step */
case DSCRV8_ENTRY_HALT_STEP_NORMAL: /* Halt step*/
case DSCRV8_ENTRY_HALT_STEP:
target->debug_reason = DBG_REASON_SINGLESTEP;
break;
case DSCRV8_ENTRY_HLT: /* HLT instruction (software breakpoint) */
case DSCRV8_ENTRY_BKPT: /* SW BKPT (?) */
case DSCRV8_ENTRY_RESET_CATCH: /* Reset catch */
case DSCRV8_ENTRY_OS_UNLOCK: /*OS unlock catch*/
case DSCRV8_ENTRY_SW_ACCESS_DBG: /*SW access dbg register*/
target->debug_reason = DBG_REASON_BREAKPOINT;
break;
case DSCRV8_ENTRY_WATCHPOINT: /* asynch watchpoint */
target->debug_reason = DBG_REASON_WATCHPOINT;
break;
case DSCRV8_ENTRY_EXCEPTION_CATCH: /*exception catch*/
target->debug_reason = DBG_REASON_EXC_CATCH;
break;
default:
target->debug_reason = DBG_REASON_UNDEFINED;
break;
}
}
/*----------------------------------------------------------------------*/
/*
* Setup and management support.
*/
/**
* Hooks up this DPM to its associated target; call only once.
* Initially this only covers the register cache.
*
* Oh, and watchpoints. Yeah.
*/
int armv8_dpm_setup(struct arm_dpm *dpm)
{
struct arm *arm = dpm->arm;
struct target *target = arm->target;
struct reg_cache *cache;
arm->dpm = dpm;
/* register access setup */
arm->full_context = armv8_dpm_full_context;
arm->read_core_reg = armv8_dpm_read_core_reg;
arm->write_core_reg = armv8_dpm_write_core_reg;
if (!arm->core_cache) {
cache = armv8_build_reg_cache(target);
if (!cache)
return ERROR_FAIL;
}
/* coprocessor access setup */
arm->mrc = dpmv8_mrc;
arm->mcr = dpmv8_mcr;
dpm->prepare = dpmv8_dpm_prepare;
dpm->finish = dpmv8_dpm_finish;
dpm->instr_execute = dpmv8_instr_execute;
dpm->instr_write_data_dcc = dpmv8_instr_write_data_dcc;
dpm->instr_write_data_dcc_64 = dpmv8_instr_write_data_dcc_64;
dpm->instr_write_data_r0 = dpmv8_instr_write_data_r0;
dpm->instr_write_data_r0_64 = dpmv8_instr_write_data_r0_64;
dpm->instr_cpsr_sync = dpmv8_instr_cpsr_sync;
dpm->instr_read_data_dcc = dpmv8_instr_read_data_dcc;
dpm->instr_read_data_dcc_64 = dpmv8_instr_read_data_dcc_64;
dpm->instr_read_data_r0 = dpmv8_instr_read_data_r0;
dpm->instr_read_data_r0_64 = dpmv8_instr_read_data_r0_64;
dpm->arm_reg_current = armv8_reg_current;
/* dpm->bpwp_enable = dpmv8_bpwp_enable; */
dpm->bpwp_disable = dpmv8_bpwp_disable;
/* breakpoint setup -- optional until it works everywhere */
if (!target->type->add_breakpoint) {
target->type->add_breakpoint = dpmv8_add_breakpoint;
target->type->remove_breakpoint = dpmv8_remove_breakpoint;
}
/* watchpoint setup */
if (!target->type->add_watchpoint) {
target->type->add_watchpoint = dpmv8_add_watchpoint;
target->type->remove_watchpoint = dpmv8_remove_watchpoint;
}
/* FIXME add vector catch support */
dpm->nbp = 1 + ((dpm->didr >> 12) & 0xf);
dpm->dbp = calloc(dpm->nbp, sizeof(*dpm->dbp));
dpm->nwp = 1 + ((dpm->didr >> 20) & 0xf);
dpm->dwp = calloc(dpm->nwp, sizeof(*dpm->dwp));
if (!dpm->dbp || !dpm->dwp) {
free(dpm->dbp);
free(dpm->dwp);
return ERROR_FAIL;
}
LOG_INFO("%s: hardware has %d breakpoints, %d watchpoints",
target_name(target), dpm->nbp, dpm->nwp);
/* REVISIT ... and some of those breakpoints could match
* execution context IDs...
*/
return ERROR_OK;
}
/**
* Reinitializes DPM state at the beginning of a new debug session
* or after a reset which may have affected the debug module.
*/
int armv8_dpm_initialize(struct arm_dpm *dpm)
{
/* Disable all breakpoints and watchpoints at startup. */
if (dpm->bpwp_disable) {
unsigned i;
for (i = 0; i < dpm->nbp; i++) {
dpm->dbp[i].bpwp.number = i;
(void) dpm->bpwp_disable(dpm, i);
}
for (i = 0; i < dpm->nwp; i++) {
dpm->dwp[i].bpwp.number = 16 + i;
(void) dpm->bpwp_disable(dpm, 16 + i);
}
} else
LOG_WARNING("%s: can't disable breakpoints and watchpoints",
target_name(dpm->arm->target));
return ERROR_OK;
}
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