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riscv-openocd/src/target/riscv/riscv-011.c

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/*
* Support for RISC-V, debug version 0.11. This was never an officially adopted
* spec, but SiFive made some silicon that uses it.
*/
#include <assert.h>
#include <stdlib.h>
#include <time.h>
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "target/target.h"
#include "target/algorithm.h"
#include "target/target_type.h"
#include "log.h"
#include "jtag/jtag.h"
#include "target/register.h"
#include "target/breakpoints.h"
#include "helper/time_support.h"
#include "riscv.h"
#include "asm.h"
#include "gdb_regs.h"
/**
* Since almost everything can be accomplish by scanning the dbus register, all
* functions here assume dbus is already selected. The exception are functions
* called directly by OpenOCD, which can't assume anything about what's
* currently in IR. They should set IR to dbus explicitly.
*/
/**
* Code structure
*
* At the bottom of the stack are the OpenOCD JTAG functions:
* jtag_add_[id]r_scan
* jtag_execute_query
* jtag_add_runtest
*
* There are a few functions to just instantly shift a register and get its
* value:
* dtmcontrol_scan
* idcode_scan
* dbus_scan
*
* Because doing one scan and waiting for the result is slow, most functions
* batch up a bunch of dbus writes and then execute them all at once. They use
* the scans "class" for this:
* scans_new
* scans_delete
* scans_execute
* scans_add_...
* Usually you new(), call a bunch of add functions, then execute() and look
* at the results by calling scans_get...()
*
* Optimized functions will directly use the scans class above, but slightly
* lazier code will use the cache functions that in turn use the scans
* functions:
* cache_get...
* cache_set...
* cache_write
* cache_set... update a local structure, which is then synced to the target
* with cache_write(). Only Debug RAM words that are actually changed are sent
* to the target. Afterwards use cache_get... to read results.
*/
#define get_field(reg, mask) (((reg) & (mask)) / ((mask) & ~((mask) << 1)))
#define set_field(reg, mask, val) (((reg) & ~(mask)) | (((val) * ((mask) & ~((mask) << 1))) & (mask)))
#define DIM(x) (sizeof(x)/sizeof(*x))
/* Constants for legacy SiFive hardware breakpoints. */
#define CSR_BPCONTROL_X (1<<0)
#define CSR_BPCONTROL_W (1<<1)
#define CSR_BPCONTROL_R (1<<2)
#define CSR_BPCONTROL_U (1<<3)
#define CSR_BPCONTROL_S (1<<4)
#define CSR_BPCONTROL_H (1<<5)
#define CSR_BPCONTROL_M (1<<6)
#define CSR_BPCONTROL_BPMATCH (0xf<<7)
#define CSR_BPCONTROL_BPACTION (0xff<<11)
#define DEBUG_ROM_START 0x800
#define DEBUG_ROM_RESUME (DEBUG_ROM_START + 4)
#define DEBUG_ROM_EXCEPTION (DEBUG_ROM_START + 8)
#define DEBUG_RAM_START 0x400
#define SETHALTNOT 0x10c
/*** JTAG registers. ***/
#define DTMCONTROL 0x10
#define DTMCONTROL_DBUS_RESET (1<<16)
#define DTMCONTROL_IDLE (7<<10)
#define DTMCONTROL_ADDRBITS (0xf<<4)
#define DTMCONTROL_VERSION (0xf)
#define DBUS 0x11
#define DBUS_OP_START 0
#define DBUS_OP_SIZE 2
typedef enum {
DBUS_OP_NOP = 0,
DBUS_OP_READ = 1,
DBUS_OP_WRITE = 2
} dbus_op_t;
typedef enum {
DBUS_STATUS_SUCCESS = 0,
DBUS_STATUS_FAILED = 2,
DBUS_STATUS_BUSY = 3
} dbus_status_t;
#define DBUS_DATA_START 2
#define DBUS_DATA_SIZE 34
#define DBUS_ADDRESS_START 36
typedef enum {
RE_OK,
RE_FAIL,
RE_AGAIN
} riscv_error_t;
typedef enum slot {
SLOT0,
SLOT1,
SLOT_LAST,
} slot_t;
/*** Debug Bus registers. ***/
#define DMCONTROL 0x10
#define DMCONTROL_INTERRUPT (((uint64_t)1)<<33)
#define DMCONTROL_HALTNOT (((uint64_t)1)<<32)
#define DMCONTROL_BUSERROR (7<<19)
#define DMCONTROL_SERIAL (3<<16)
#define DMCONTROL_AUTOINCREMENT (1<<15)
#define DMCONTROL_ACCESS (7<<12)
#define DMCONTROL_HARTID (0x3ff<<2)
#define DMCONTROL_NDRESET (1<<1)
#define DMCONTROL_FULLRESET 1
#define DMINFO 0x11
#define DMINFO_ABUSSIZE (0x7fU<<25)
#define DMINFO_SERIALCOUNT (0xf<<21)
#define DMINFO_ACCESS128 (1<<20)
#define DMINFO_ACCESS64 (1<<19)
#define DMINFO_ACCESS32 (1<<18)
#define DMINFO_ACCESS16 (1<<17)
#define DMINFO_ACCESS8 (1<<16)
#define DMINFO_DRAMSIZE (0x3f<<10)
#define DMINFO_AUTHENTICATED (1<<5)
#define DMINFO_AUTHBUSY (1<<4)
#define DMINFO_AUTHTYPE (3<<2)
#define DMINFO_VERSION 3
/*** Info about the core being debugged. ***/
#define DBUS_ADDRESS_UNKNOWN 0xffff
#define DRAM_CACHE_SIZE 16
struct trigger {
uint64_t address;
uint32_t length;
uint64_t mask;
uint64_t value;
bool read, write, execute;
int unique_id;
};
struct memory_cache_line {
uint32_t data;
bool valid;
bool dirty;
};
typedef struct {
/* Number of address bits in the dbus register. */
uint8_t addrbits;
/* Number of words in Debug RAM. */
unsigned int dramsize;
uint64_t dcsr;
uint64_t dpc;
uint64_t tselect;
bool tselect_dirty;
/* The value that mstatus actually has on the target right now. This is not
* the value we present to the user. That one may be stored in the
* reg_cache. */
uint64_t mstatus_actual;
struct memory_cache_line dram_cache[DRAM_CACHE_SIZE];
/* Number of run-test/idle cycles the target requests we do after each dbus
* access. */
unsigned int dtmcontrol_idle;
/* This value is incremented every time a dbus access comes back as "busy".
* It's used to determine how many run-test/idle cycles to feed the target
* in between accesses. */
unsigned int dbus_busy_delay;
/* This value is incremented every time we read the debug interrupt as
* high. It's used to add extra run-test/idle cycles after setting debug
* interrupt high, so ideally we never have to perform a whole extra scan
* before the interrupt is cleared. */
unsigned int interrupt_high_delay;
bool need_strict_step;
bool never_halted;
} riscv011_info_t;
typedef struct {
bool haltnot;
bool interrupt;
} bits_t;
/*** Necessary prototypes. ***/
static int poll_target(struct target *target, bool announce);
static int riscv011_poll(struct target *target);
static riscv_reg_t get_register(struct target *target, int hartid, int regid);
/*** Utility functions. ***/
#define DEBUG_LENGTH 264
static riscv011_info_t *get_info(const struct target *target)
{
riscv_info_t *info = (riscv_info_t *) target->arch_info;
return (riscv011_info_t *) info->version_specific;
}
static unsigned int slot_offset(const struct target *target, slot_t slot)
{
riscv011_info_t *info = get_info(target);
switch (riscv_xlen(target)) {
case 32:
switch (slot) {
case SLOT0: return 4;
case SLOT1: return 5;
case SLOT_LAST: return info->dramsize-1;
}
case 64:
switch (slot) {
case SLOT0: return 4;
case SLOT1: return 6;
case SLOT_LAST: return info->dramsize-2;
}
}
LOG_ERROR("slot_offset called with xlen=%d, slot=%d",
riscv_xlen(target), slot);
assert(0);
return 0; /* Silence -Werror=return-type */
}
static uint32_t load_slot(const struct target *target, unsigned int dest,
slot_t slot)
{
unsigned int offset = DEBUG_RAM_START + 4 * slot_offset(target, slot);
return load(target, dest, ZERO, offset);
}
static uint32_t store_slot(const struct target *target, unsigned int src,
slot_t slot)
{
unsigned int offset = DEBUG_RAM_START + 4 * slot_offset(target, slot);
return store(target, src, ZERO, offset);
}
static uint16_t dram_address(unsigned int index)
{
if (index < 0x10)
return index;
else
return 0x40 + index - 0x10;
}
static uint32_t dtmcontrol_scan(struct target *target, uint32_t out)
{
struct scan_field field;
uint8_t in_value[4];
uint8_t out_value[4];
buf_set_u32(out_value, 0, 32, out);
jtag_add_ir_scan(target->tap, &select_dtmcontrol, TAP_IDLE);
field.num_bits = 32;
field.out_value = out_value;
field.in_value = in_value;
jtag_add_dr_scan(target->tap, 1, &field, TAP_IDLE);
/* Always return to dbus. */
jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
int retval = jtag_execute_queue();
if (retval != ERROR_OK) {
LOG_ERROR("failed jtag scan: %d", retval);
return retval;
}
uint32_t in = buf_get_u32(field.in_value, 0, 32);
LOG_DEBUG("DTMCONTROL: 0x%x -> 0x%x", out, in);
return in;
}
static uint32_t idcode_scan(struct target *target)
{
struct scan_field field;
uint8_t in_value[4];
jtag_add_ir_scan(target->tap, &select_idcode, TAP_IDLE);
field.num_bits = 32;
field.out_value = NULL;
field.in_value = in_value;
jtag_add_dr_scan(target->tap, 1, &field, TAP_IDLE);
int retval = jtag_execute_queue();
if (retval != ERROR_OK) {
LOG_ERROR("failed jtag scan: %d", retval);
return retval;
}
/* Always return to dbus. */
jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
uint32_t in = buf_get_u32(field.in_value, 0, 32);
LOG_DEBUG("IDCODE: 0x0 -> 0x%x", in);
return in;
}
static void increase_dbus_busy_delay(struct target *target)
{
riscv011_info_t *info = get_info(target);
info->dbus_busy_delay += info->dbus_busy_delay / 10 + 1;
LOG_INFO("dtmcontrol_idle=%d, dbus_busy_delay=%d, interrupt_high_delay=%d",
info->dtmcontrol_idle, info->dbus_busy_delay,
info->interrupt_high_delay);
dtmcontrol_scan(target, DTMCONTROL_DBUS_RESET);
}
static void increase_interrupt_high_delay(struct target *target)
{
riscv011_info_t *info = get_info(target);
info->interrupt_high_delay += info->interrupt_high_delay / 10 + 1;
LOG_INFO("dtmcontrol_idle=%d, dbus_busy_delay=%d, interrupt_high_delay=%d",
info->dtmcontrol_idle, info->dbus_busy_delay,
info->interrupt_high_delay);
}
static void add_dbus_scan(const struct target *target, struct scan_field *field,
uint8_t *out_value, uint8_t *in_value, dbus_op_t op,
uint16_t address, uint64_t data)
{
riscv011_info_t *info = get_info(target);
field->num_bits = info->addrbits + DBUS_OP_SIZE + DBUS_DATA_SIZE;
field->in_value = in_value;
field->out_value = out_value;
buf_set_u64(out_value, DBUS_OP_START, DBUS_OP_SIZE, op);
buf_set_u64(out_value, DBUS_DATA_START, DBUS_DATA_SIZE, data);
buf_set_u64(out_value, DBUS_ADDRESS_START, info->addrbits, address);
jtag_add_dr_scan(target->tap, 1, field, TAP_IDLE);
int idle_count = info->dtmcontrol_idle + info->dbus_busy_delay;
if (data & DMCONTROL_INTERRUPT)
idle_count += info->interrupt_high_delay;
if (idle_count)
jtag_add_runtest(idle_count, TAP_IDLE);
}
static void dump_field(const struct scan_field *field)
{
static const char * const op_string[] = {"nop", "r", "w", "?"};
static const char * const status_string[] = {"+", "?", "F", "b"};
if (debug_level < LOG_LVL_DEBUG)
return;
uint64_t out = buf_get_u64(field->out_value, 0, field->num_bits);
unsigned int out_op = (out >> DBUS_OP_START) & ((1 << DBUS_OP_SIZE) - 1);
char out_interrupt = ((out >> DBUS_DATA_START) & DMCONTROL_INTERRUPT) ? 'i' : '.';
char out_haltnot = ((out >> DBUS_DATA_START) & DMCONTROL_HALTNOT) ? 'h' : '.';
unsigned int out_data = out >> 2;
unsigned int out_address = out >> DBUS_ADDRESS_START;
uint64_t in = buf_get_u64(field->in_value, 0, field->num_bits);
unsigned int in_op = (in >> DBUS_OP_START) & ((1 << DBUS_OP_SIZE) - 1);
char in_interrupt = ((in >> DBUS_DATA_START) & DMCONTROL_INTERRUPT) ? 'i' : '.';
char in_haltnot = ((in >> DBUS_DATA_START) & DMCONTROL_HALTNOT) ? 'h' : '.';
unsigned int in_data = in >> 2;
unsigned int in_address = in >> DBUS_ADDRESS_START;
log_printf_lf(LOG_LVL_DEBUG,
__FILE__, __LINE__, "scan",
"%db %s %c%c:%08x @%02x -> %s %c%c:%08x @%02x",
field->num_bits,
op_string[out_op], out_interrupt, out_haltnot, out_data,
out_address,
status_string[in_op], in_interrupt, in_haltnot, in_data,
in_address);
}
static dbus_status_t dbus_scan(struct target *target, uint16_t *address_in,
uint64_t *data_in, dbus_op_t op, uint16_t address_out, uint64_t data_out)
{
riscv011_info_t *info = get_info(target);
uint8_t in[8] = {0};
uint8_t out[8];
struct scan_field field = {
.num_bits = info->addrbits + DBUS_OP_SIZE + DBUS_DATA_SIZE,
.out_value = out,
.in_value = in
};
assert(info->addrbits != 0);
buf_set_u64(out, DBUS_OP_START, DBUS_OP_SIZE, op);
buf_set_u64(out, DBUS_DATA_START, DBUS_DATA_SIZE, data_out);
buf_set_u64(out, DBUS_ADDRESS_START, info->addrbits, address_out);
/* Assume dbus is already selected. */
jtag_add_dr_scan(target->tap, 1, &field, TAP_IDLE);
int idle_count = info->dtmcontrol_idle + info->dbus_busy_delay;
if (idle_count)
jtag_add_runtest(idle_count, TAP_IDLE);
int retval = jtag_execute_queue();
if (retval != ERROR_OK) {
LOG_ERROR("dbus_scan failed jtag scan");
return retval;
}
if (data_in)
*data_in = buf_get_u64(in, DBUS_DATA_START, DBUS_DATA_SIZE);
if (address_in)
*address_in = buf_get_u32(in, DBUS_ADDRESS_START, info->addrbits);
dump_field(&field);
return buf_get_u32(in, DBUS_OP_START, DBUS_OP_SIZE);
}
static uint64_t dbus_read(struct target *target, uint16_t address)
{
uint64_t value;
dbus_status_t status;
uint16_t address_in;
unsigned i = 0;
do {
status = dbus_scan(target, &address_in, &value, DBUS_OP_READ, address, 0);
if (status == DBUS_STATUS_BUSY)
increase_dbus_busy_delay(target);
} while (((status == DBUS_STATUS_BUSY) || (address_in != address)) &&
i++ < 256);
if (status != DBUS_STATUS_SUCCESS)
LOG_ERROR("failed read from 0x%x; value=0x%" PRIx64 ", status=%d\n", address, value, status);
return value;
}
static void dbus_write(struct target *target, uint16_t address, uint64_t value)
{
dbus_status_t status = DBUS_STATUS_BUSY;
unsigned i = 0;
while (status == DBUS_STATUS_BUSY && i++ < 256) {
status = dbus_scan(target, NULL, NULL, DBUS_OP_WRITE, address, value);
if (status == DBUS_STATUS_BUSY)
increase_dbus_busy_delay(target);
}
if (status != DBUS_STATUS_SUCCESS)
LOG_ERROR("failed to write 0x%" PRIx64 " to 0x%x; status=%d\n", value, address, status);
}
/*** scans "class" ***/
typedef struct {
/* Number of scans that space is reserved for. */
unsigned int scan_count;
/* Size reserved in memory for each scan, in bytes. */
unsigned int scan_size;
unsigned int next_scan;
uint8_t *in;
uint8_t *out;
struct scan_field *field;
const struct target *target;
} scans_t;
static scans_t *scans_new(struct target *target, unsigned int scan_count)
{
scans_t *scans = malloc(sizeof(scans_t));
scans->scan_count = scan_count;
/* This code also gets called before xlen is detected. */
if (riscv_xlen(target))
scans->scan_size = 2 + riscv_xlen(target) / 8;
else
scans->scan_size = 2 + 128 / 8;
scans->next_scan = 0;
scans->in = calloc(scans->scan_size, scans->scan_count);
scans->out = calloc(scans->scan_size, scans->scan_count);
scans->field = calloc(scans->scan_count, sizeof(struct scan_field));
scans->target = target;
return scans;
}
static scans_t *scans_delete(scans_t *scans)
{
assert(scans);
free(scans->field);
free(scans->out);
free(scans->in);
free(scans);
return NULL;
}
static void scans_reset(scans_t *scans)
{
scans->next_scan = 0;
}
static void scans_dump(scans_t *scans)
{
for (unsigned int i = 0; i < scans->next_scan; i++)
dump_field(&scans->field[i]);
}
static int scans_execute(scans_t *scans)
{
int retval = jtag_execute_queue();
if (retval != ERROR_OK) {
LOG_ERROR("failed jtag scan: %d", retval);
return retval;
}
scans_dump(scans);
return ERROR_OK;
}
/** Add a 32-bit dbus write to the scans structure. */
static void scans_add_write32(scans_t *scans, uint16_t address, uint32_t data,
bool set_interrupt)
{
const unsigned int i = scans->next_scan;
int data_offset = scans->scan_size * i;
add_dbus_scan(scans->target, &scans->field[i], scans->out + data_offset,
scans->in + data_offset, DBUS_OP_WRITE, address,
(set_interrupt ? DMCONTROL_INTERRUPT : 0) | DMCONTROL_HALTNOT | data);
scans->next_scan++;
assert(scans->next_scan <= scans->scan_count);
}
/** Add a 32-bit dbus write for an instruction that jumps to the beginning of
* debug RAM. */
static void scans_add_write_jump(scans_t *scans, uint16_t address,
bool set_interrupt)
{
scans_add_write32(scans, address,
jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*address))),
set_interrupt);
}
/** Add a 32-bit dbus write for an instruction that loads from the indicated
* slot. */
static void scans_add_write_load(scans_t *scans, uint16_t address,
unsigned int reg, slot_t slot, bool set_interrupt)
{
scans_add_write32(scans, address, load_slot(scans->target, reg, slot),
set_interrupt);
}
/** Add a 32-bit dbus write for an instruction that stores to the indicated
* slot. */
static void scans_add_write_store(scans_t *scans, uint16_t address,
unsigned int reg, slot_t slot, bool set_interrupt)
{
scans_add_write32(scans, address, store_slot(scans->target, reg, slot),
set_interrupt);
}
/** Add a 32-bit dbus read. */
static void scans_add_read32(scans_t *scans, uint16_t address, bool set_interrupt)
{
assert(scans->next_scan < scans->scan_count);
const unsigned int i = scans->next_scan;
int data_offset = scans->scan_size * i;
add_dbus_scan(scans->target, &scans->field[i], scans->out + data_offset,
scans->in + data_offset, DBUS_OP_READ, address,
(set_interrupt ? DMCONTROL_INTERRUPT : 0) | DMCONTROL_HALTNOT);
scans->next_scan++;
}
/** Add one or more scans to read the indicated slot. */
static void scans_add_read(scans_t *scans, slot_t slot, bool set_interrupt)
{
const struct target *target = scans->target;
switch (riscv_xlen(target)) {
case 32:
scans_add_read32(scans, slot_offset(target, slot), set_interrupt);
break;
case 64:
scans_add_read32(scans, slot_offset(target, slot), false);
scans_add_read32(scans, slot_offset(target, slot) + 1, set_interrupt);
break;
}
}
static uint32_t scans_get_u32(scans_t *scans, unsigned int index,
unsigned first, unsigned num)
{
return buf_get_u32(scans->in + scans->scan_size * index, first, num);
}
static uint64_t scans_get_u64(scans_t *scans, unsigned int index,
unsigned first, unsigned num)
{
return buf_get_u64(scans->in + scans->scan_size * index, first, num);
}
/*** end of scans class ***/
static uint32_t dram_read32(struct target *target, unsigned int index)
{
uint16_t address = dram_address(index);
uint32_t value = dbus_read(target, address);
return value;
}
static void dram_write32(struct target *target, unsigned int index, uint32_t value,
bool set_interrupt)
{
uint64_t dbus_value = DMCONTROL_HALTNOT | value;
if (set_interrupt)
dbus_value |= DMCONTROL_INTERRUPT;
dbus_write(target, dram_address(index), dbus_value);
}
/** Read the haltnot and interrupt bits. */
static bits_t read_bits(struct target *target)
{
uint64_t value;
dbus_status_t status;
uint16_t address_in;
riscv011_info_t *info = get_info(target);
bits_t err_result = {
.haltnot = 0,
.interrupt = 0
};
do {
unsigned i = 0;
do {
status = dbus_scan(target, &address_in, &value, DBUS_OP_READ, 0, 0);
if (status == DBUS_STATUS_BUSY) {
if (address_in == (1<<info->addrbits) - 1 &&
value == (1ULL<<DBUS_DATA_SIZE) - 1) {
LOG_ERROR("TDO seems to be stuck high.");
return err_result;
}
increase_dbus_busy_delay(target);
}
} while (status == DBUS_STATUS_BUSY && i++ < 256);
if (i >= 256) {
LOG_ERROR("Failed to read from 0x%x; status=%d", address_in, status);
return err_result;
}
} while (address_in > 0x10 && address_in != DMCONTROL);
bits_t result = {
.haltnot = get_field(value, DMCONTROL_HALTNOT),
.interrupt = get_field(value, DMCONTROL_INTERRUPT)
};
return result;
}
static int wait_for_debugint_clear(struct target *target, bool ignore_first)
{
time_t start = time(NULL);
if (ignore_first) {
/* Throw away the results of the first read, since they'll contain the
* result of the read that happened just before debugint was set.
* (Assuming the last scan before calling this function was one that
* sets debugint.) */
read_bits(target);
}
while (1) {
bits_t bits = read_bits(target);
if (!bits.interrupt)
return ERROR_OK;
if (time(NULL) - start > riscv_command_timeout_sec) {
LOG_ERROR("Timed out waiting for debug int to clear."
"Increase timeout with riscv set_command_timeout_sec.");
return ERROR_FAIL;
}
}
}
static int dram_check32(struct target *target, unsigned int index,
uint32_t expected)
{
uint16_t address = dram_address(index);
uint32_t actual = dbus_read(target, address);
if (expected != actual) {
LOG_ERROR("Wrote 0x%x to Debug RAM at %d, but read back 0x%x",
expected, index, actual);
return ERROR_FAIL;
}
return ERROR_OK;
}
static void cache_set32(struct target *target, unsigned int index, uint32_t data)
{
riscv011_info_t *info = get_info(target);
if (info->dram_cache[index].valid &&
info->dram_cache[index].data == data) {
/* This is already preset on the target. */
LOG_DEBUG("cache[0x%x] = 0x%08x: DASM(0x%x) (hit)", index, data, data);
return;
}
LOG_DEBUG("cache[0x%x] = 0x%08x: DASM(0x%x)", index, data, data);
info->dram_cache[index].data = data;
info->dram_cache[index].valid = true;
info->dram_cache[index].dirty = true;
}
static void cache_set(struct target *target, slot_t slot, uint64_t data)
{
unsigned int offset = slot_offset(target, slot);
cache_set32(target, offset, data);
if (riscv_xlen(target) > 32)
cache_set32(target, offset + 1, data >> 32);
}
static void cache_set_jump(struct target *target, unsigned int index)
{
cache_set32(target, index,
jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*index))));
}
static void cache_set_load(struct target *target, unsigned int index,
unsigned int reg, slot_t slot)
{
uint16_t offset = DEBUG_RAM_START + 4 * slot_offset(target, slot);
cache_set32(target, index, load(target, reg, ZERO, offset));
}
static void cache_set_store(struct target *target, unsigned int index,
unsigned int reg, slot_t slot)
{
uint16_t offset = DEBUG_RAM_START + 4 * slot_offset(target, slot);
cache_set32(target, index, store(target, reg, ZERO, offset));
}
static void dump_debug_ram(struct target *target)
{
for (unsigned int i = 0; i < DRAM_CACHE_SIZE; i++) {
uint32_t value = dram_read32(target, i);
LOG_ERROR("Debug RAM 0x%x: 0x%08x", i, value);
}
}
/* Call this if the code you just ran writes to debug RAM entries 0 through 3. */
static void cache_invalidate(struct target *target)
{
riscv011_info_t *info = get_info(target);
for (unsigned int i = 0; i < info->dramsize; i++) {
info->dram_cache[i].valid = false;
info->dram_cache[i].dirty = false;
}
}
/* Called by cache_write() after the program has run. Also call this if you're
* running programs without calling cache_write(). */
static void cache_clean(struct target *target)
{
riscv011_info_t *info = get_info(target);
for (unsigned int i = 0; i < info->dramsize; i++) {
if (i >= 4)
info->dram_cache[i].valid = false;
info->dram_cache[i].dirty = false;
}
}
static int cache_check(struct target *target)
{
riscv011_info_t *info = get_info(target);
int error = 0;
for (unsigned int i = 0; i < info->dramsize; i++) {
if (info->dram_cache[i].valid && !info->dram_cache[i].dirty) {
if (dram_check32(target, i, info->dram_cache[i].data) != ERROR_OK)
error++;
}
}
if (error) {
dump_debug_ram(target);
return ERROR_FAIL;
}
return ERROR_OK;
}
/** Write cache to the target, and optionally run the program.
* Then read the value at address into the cache, assuming address < 128. */
#define CACHE_NO_READ 128
static int cache_write(struct target *target, unsigned int address, bool run)
{
LOG_DEBUG("enter");
riscv011_info_t *info = get_info(target);
scans_t *scans = scans_new(target, info->dramsize + 2);
unsigned int last = info->dramsize;
for (unsigned int i = 0; i < info->dramsize; i++) {
if (info->dram_cache[i].dirty)
last = i;
}
if (last == info->dramsize) {
/* Nothing needs to be written to RAM. */
dbus_write(target, DMCONTROL, DMCONTROL_HALTNOT | (run ? DMCONTROL_INTERRUPT : 0));
} else {
for (unsigned int i = 0; i < info->dramsize; i++) {
if (info->dram_cache[i].dirty) {
bool set_interrupt = (i == last && run);
scans_add_write32(scans, i, info->dram_cache[i].data,
set_interrupt);
}
}
}
if (run || address < CACHE_NO_READ) {
/* Throw away the results of the first read, since it'll contain the
* result of the read that happened just before debugint was set. */
scans_add_read32(scans, address, false);
/* This scan contains the results of the read the caller requested, as
* well as an interrupt bit worth looking at. */
scans_add_read32(scans, address, false);
}
int retval = scans_execute(scans);
if (retval != ERROR_OK) {
LOG_ERROR("JTAG execute failed.");
return retval;
}
int errors = 0;
for (unsigned int i = 0; i < scans->next_scan; i++) {
dbus_status_t status = scans_get_u32(scans, i, DBUS_OP_START,
DBUS_OP_SIZE);
switch (status) {
case DBUS_STATUS_SUCCESS:
break;
case DBUS_STATUS_FAILED:
LOG_ERROR("Debug RAM write failed. Hardware error?");
return ERROR_FAIL;
case DBUS_STATUS_BUSY:
errors++;
break;
default:
LOG_ERROR("Got invalid bus access status: %d", status);
return ERROR_FAIL;
}
}
if (errors) {
increase_dbus_busy_delay(target);
/* Try again, using the slow careful code.
* Write all RAM, just to be extra cautious. */
for (unsigned int i = 0; i < info->dramsize; i++) {
if (i == last && run)
dram_write32(target, last, info->dram_cache[last].data, true);
else
dram_write32(target, i, info->dram_cache[i].data, false);
info->dram_cache[i].dirty = false;
}
if (run)
cache_clean(target);
if (wait_for_debugint_clear(target, true) != ERROR_OK) {
LOG_ERROR("Debug interrupt didn't clear.");
dump_debug_ram(target);
return ERROR_FAIL;
}
} else {
if (run) {
cache_clean(target);
} else {
for (unsigned int i = 0; i < info->dramsize; i++)
info->dram_cache[i].dirty = false;
}
if (run || address < CACHE_NO_READ) {
int interrupt = scans_get_u32(scans, scans->next_scan-1,
DBUS_DATA_START + 33, 1);
if (interrupt) {
increase_interrupt_high_delay(target);
/* Slow path wait for it to clear. */
if (wait_for_debugint_clear(target, false) != ERROR_OK) {
LOG_ERROR("Debug interrupt didn't clear.");
dump_debug_ram(target);
return ERROR_FAIL;
}
} else {
/* We read a useful value in that last scan. */
unsigned int read_addr = scans_get_u32(scans, scans->next_scan-1,
DBUS_ADDRESS_START, info->addrbits);
if (read_addr != address) {
LOG_INFO("Got data from 0x%x but expected it from 0x%x",
read_addr, address);
}
info->dram_cache[read_addr].data =
scans_get_u32(scans, scans->next_scan-1, DBUS_DATA_START, 32);
info->dram_cache[read_addr].valid = true;
}
}
}
scans_delete(scans);
LOG_DEBUG("exit");
return ERROR_OK;
}
static uint32_t cache_get32(struct target *target, unsigned int address)
{
riscv011_info_t *info = get_info(target);
if (!info->dram_cache[address].valid) {
info->dram_cache[address].data = dram_read32(target, address);
info->dram_cache[address].valid = true;
}
return info->dram_cache[address].data;
}
static uint64_t cache_get(struct target *target, slot_t slot)
{
unsigned int offset = slot_offset(target, slot);
uint64_t value = cache_get32(target, offset);
if (riscv_xlen(target) > 32)
value |= ((uint64_t) cache_get32(target, offset + 1)) << 32;
return value;
}
/* Write instruction that jumps from the specified word in Debug RAM to resume
* in Debug ROM. */
static void dram_write_jump(struct target *target, unsigned int index,
bool set_interrupt)
{
dram_write32(target, index,
jal(0, (uint32_t) (DEBUG_ROM_RESUME - (DEBUG_RAM_START + 4*index))),
set_interrupt);
}
static int wait_for_state(struct target *target, enum target_state state)
{
time_t start = time(NULL);
while (1) {
int result = riscv011_poll(target);
if (result != ERROR_OK)
return result;
if (target->state == state)
return ERROR_OK;
if (time(NULL) - start > riscv_command_timeout_sec) {
LOG_ERROR("Timed out waiting for state %d. "
"Increase timeout with riscv set_command_timeout_sec.", state);
return ERROR_FAIL;
}
}
}
static int read_csr(struct target *target, uint64_t *value, uint32_t csr)
{
riscv011_info_t *info = get_info(target);
cache_set32(target, 0, csrr(S0, csr));
cache_set_store(target, 1, S0, SLOT0);
cache_set_jump(target, 2);
if (cache_write(target, 4, true) != ERROR_OK)
return ERROR_FAIL;
*value = cache_get(target, SLOT0);
LOG_DEBUG("csr 0x%x = 0x%" PRIx64, csr, *value);
uint32_t exception = cache_get32(target, info->dramsize-1);
if (exception) {
LOG_WARNING("Got exception 0x%x when reading CSR 0x%x", exception, csr);
*value = ~0;
return ERROR_FAIL;
}
return ERROR_OK;
}
static int write_csr(struct target *target, uint32_t csr, uint64_t value)
{
LOG_DEBUG("csr 0x%x <- 0x%" PRIx64, csr, value);
cache_set_load(target, 0, S0, SLOT0);
cache_set32(target, 1, csrw(S0, csr));
cache_set_jump(target, 2);
cache_set(target, SLOT0, value);
if (cache_write(target, 4, true) != ERROR_OK)
return ERROR_FAIL;
return ERROR_OK;
}
static int write_gpr(struct target *target, unsigned int gpr, uint64_t value)
{
cache_set_load(target, 0, gpr, SLOT0);
cache_set_jump(target, 1);
cache_set(target, SLOT0, value);
if (cache_write(target, 4, true) != ERROR_OK)
return ERROR_FAIL;
return ERROR_OK;
}
static int maybe_read_tselect(struct target *target)
{
riscv011_info_t *info = get_info(target);
if (info->tselect_dirty) {
int result = read_csr(target, &info->tselect, CSR_TSELECT);
if (result != ERROR_OK)
return result;
info->tselect_dirty = false;
}
return ERROR_OK;
}
static int maybe_write_tselect(struct target *target)
{
riscv011_info_t *info = get_info(target);
if (!info->tselect_dirty) {
int result = write_csr(target, CSR_TSELECT, info->tselect);
if (result != ERROR_OK)
return result;
info->tselect_dirty = true;
}
return ERROR_OK;
}
static int execute_resume(struct target *target, bool step)
{
riscv011_info_t *info = get_info(target);
LOG_DEBUG("step=%d", step);
maybe_write_tselect(target);
/* TODO: check if dpc is dirty (which also is true if an exception was hit
* at any time) */
cache_set_load(target, 0, S0, SLOT0);
cache_set32(target, 1, csrw(S0, CSR_DPC));
cache_set_jump(target, 2);
cache_set(target, SLOT0, info->dpc);
if (cache_write(target, 4, true) != ERROR_OK)
return ERROR_FAIL;
struct reg *mstatus_reg = &target->reg_cache->reg_list[GDB_REGNO_MSTATUS];
if (mstatus_reg->valid) {
uint64_t mstatus_user = buf_get_u64(mstatus_reg->value, 0, riscv_xlen(target));
if (mstatus_user != info->mstatus_actual) {
cache_set_load(target, 0, S0, SLOT0);
cache_set32(target, 1, csrw(S0, CSR_MSTATUS));
cache_set_jump(target, 2);
cache_set(target, SLOT0, mstatus_user);
if (cache_write(target, 4, true) != ERROR_OK)
return ERROR_FAIL;
}
}
info->dcsr |= DCSR_EBREAKM | DCSR_EBREAKH | DCSR_EBREAKS | DCSR_EBREAKU;
info->dcsr &= ~DCSR_HALT;
if (step)
info->dcsr |= DCSR_STEP;
else
info->dcsr &= ~DCSR_STEP;
dram_write32(target, 0, lw(S0, ZERO, DEBUG_RAM_START + 16), false);
dram_write32(target, 1, csrw(S0, CSR_DCSR), false);
dram_write32(target, 2, fence_i(), false);
dram_write_jump(target, 3, false);
/* Write DCSR value, set interrupt and clear haltnot. */
uint64_t dbus_value = DMCONTROL_INTERRUPT | info->dcsr;
dbus_write(target, dram_address(4), dbus_value);
cache_invalidate(target);
if (wait_for_debugint_clear(target, true) != ERROR_OK) {
LOG_ERROR("Debug interrupt didn't clear.");
return ERROR_FAIL;
}
target->state = TARGET_RUNNING;
register_cache_invalidate(target->reg_cache);
return ERROR_OK;
}
/* Execute a step, and wait for reentry into Debug Mode. */
static int full_step(struct target *target, bool announce)
{
int result = execute_resume(target, true);
if (result != ERROR_OK)
return result;
time_t start = time(NULL);
while (1) {
result = poll_target(target, announce);
if (result != ERROR_OK)
return result;
if (target->state != TARGET_DEBUG_RUNNING)
break;
if (time(NULL) - start > riscv_command_timeout_sec) {
LOG_ERROR("Timed out waiting for step to complete."
"Increase timeout with riscv set_command_timeout_sec");
return ERROR_FAIL;
}
}
return ERROR_OK;
}
static int resume(struct target *target, int debug_execution, bool step)
{
if (debug_execution) {
LOG_ERROR("TODO: debug_execution is true");
return ERROR_FAIL;
}
return execute_resume(target, step);
}
static uint64_t reg_cache_get(struct target *target, unsigned int number)
{
struct reg *r = &target->reg_cache->reg_list[number];
if (!r->valid) {
LOG_ERROR("Register cache entry for %d is invalid!", number);
assert(r->valid);
}
uint64_t value = buf_get_u64(r->value, 0, r->size);
LOG_DEBUG("%s = 0x%" PRIx64, r->name, value);
return value;
}
static void reg_cache_set(struct target *target, unsigned int number,
uint64_t value)
{
struct reg *r = &target->reg_cache->reg_list[number];
LOG_DEBUG("%s <= 0x%" PRIx64, r->name, value);
r->valid = true;
buf_set_u64(r->value, 0, r->size, value);
}
static int update_mstatus_actual(struct target *target)
{
struct reg *mstatus_reg = &target->reg_cache->reg_list[GDB_REGNO_MSTATUS];
if (mstatus_reg->valid) {
/* We previously made it valid. */
return ERROR_OK;
}
/* Force reading the register. In that process mstatus_actual will be
* updated. */
get_register(target, 0, GDB_REGNO_MSTATUS);
return ERROR_OK;
}
/*** OpenOCD target functions. ***/
static int register_read(struct target *target, riscv_reg_t *value, int regnum)
{
riscv011_info_t *info = get_info(target);
if (regnum >= GDB_REGNO_CSR0 && regnum <= GDB_REGNO_CSR4095) {
cache_set32(target, 0, csrr(S0, regnum - GDB_REGNO_CSR0));
cache_set_store(target, 1, S0, SLOT0);
cache_set_jump(target, 2);
} else {
LOG_ERROR("Don't know how to read register %d", regnum);
return ERROR_FAIL;
}
if (cache_write(target, 4, true) != ERROR_OK)
return ERROR_FAIL;
uint32_t exception = cache_get32(target, info->dramsize-1);
if (exception) {
LOG_WARNING("Got exception 0x%x when reading register %d", exception,
regnum);
*value = ~0;
return ERROR_FAIL;
}
*value = cache_get(target, SLOT0);
LOG_DEBUG("reg[%d]=0x%" PRIx64, regnum, *value);
if (regnum == GDB_REGNO_MSTATUS)
info->mstatus_actual = *value;
return ERROR_OK;
}
/* Write the register. No caching or games. */
static int register_write(struct target *target, unsigned int number,
uint64_t value)
{
riscv011_info_t *info = get_info(target);
maybe_write_tselect(target);
if (number == S0) {
cache_set_load(target, 0, S0, SLOT0);
cache_set32(target, 1, csrw(S0, CSR_DSCRATCH));
cache_set_jump(target, 2);
} else if (number == S1) {
cache_set_load(target, 0, S0, SLOT0);
cache_set_store(target, 1, S0, SLOT_LAST);
cache_set_jump(target, 2);
} else if (number <= GDB_REGNO_XPR31) {
cache_set_load(target, 0, number - GDB_REGNO_ZERO, SLOT0);
cache_set_jump(target, 1);
} else if (number == GDB_REGNO_PC) {
info->dpc = value;
return ERROR_OK;
} else if (number >= GDB_REGNO_FPR0 && number <= GDB_REGNO_FPR31) {
int result = update_mstatus_actual(target);
if (result != ERROR_OK)
return result;
unsigned i = 0;
if ((info->mstatus_actual & MSTATUS_FS) == 0) {
info->mstatus_actual = set_field(info->mstatus_actual, MSTATUS_FS, 1);
cache_set_load(target, i++, S0, SLOT1);
cache_set32(target, i++, csrw(S0, CSR_MSTATUS));
cache_set(target, SLOT1, info->mstatus_actual);
}
if (riscv_xlen(target) == 32)
cache_set32(target, i++, flw(number - GDB_REGNO_FPR0, 0, DEBUG_RAM_START + 16));
else
cache_set32(target, i++, fld(number - GDB_REGNO_FPR0, 0, DEBUG_RAM_START + 16));
cache_set_jump(target, i++);
} else if (number >= GDB_REGNO_CSR0 && number <= GDB_REGNO_CSR4095) {
cache_set_load(target, 0, S0, SLOT0);
cache_set32(target, 1, csrw(S0, number - GDB_REGNO_CSR0));
cache_set_jump(target, 2);
if (number == GDB_REGNO_MSTATUS)
info->mstatus_actual = value;
} else if (number == GDB_REGNO_PRIV) {
info->dcsr = set_field(info->dcsr, DCSR_PRV, value);
return ERROR_OK;
} else {
LOG_ERROR("Don't know how to write register %d", number);
return ERROR_FAIL;
}
cache_set(target, SLOT0, value);
if (cache_write(target, info->dramsize - 1, true) != ERROR_OK)
return ERROR_FAIL;
uint32_t exception = cache_get32(target, info->dramsize-1);
if (exception) {
LOG_WARNING("Got exception 0x%x when writing register %d", exception,
number);
return ERROR_FAIL;
}
return ERROR_OK;
}
static riscv_reg_t get_register(struct target *target, int hartid, int regid)
{
assert(hartid == 0);
riscv011_info_t *info = get_info(target);
maybe_write_tselect(target);
riscv_reg_t value = ~0;
if (regid <= GDB_REGNO_XPR31) {
value = reg_cache_get(target, regid);
} else if (regid == GDB_REGNO_PC) {
value = info->dpc;
} else if (regid >= GDB_REGNO_FPR0 && regid <= GDB_REGNO_FPR31) {
int result = update_mstatus_actual(target);
if (result != ERROR_OK)
return ~0;
unsigned i = 0;
if ((info->mstatus_actual & MSTATUS_FS) == 0) {
info->mstatus_actual = set_field(info->mstatus_actual, MSTATUS_FS, 1);
cache_set_load(target, i++, S0, SLOT1);
cache_set32(target, i++, csrw(S0, CSR_MSTATUS));
cache_set(target, SLOT1, info->mstatus_actual);
}
if (riscv_xlen(target) == 32)
cache_set32(target, i++, fsw(regid - GDB_REGNO_FPR0, 0, DEBUG_RAM_START + 16));
else
cache_set32(target, i++, fsd(regid - GDB_REGNO_FPR0, 0, DEBUG_RAM_START + 16));
cache_set_jump(target, i++);
if (cache_write(target, 4, true) != ERROR_OK)
return ~0;
} else if (regid == GDB_REGNO_PRIV) {
value = get_field(info->dcsr, DCSR_PRV);
} else if (register_read(target, &value, regid) != ERROR_OK) {
value = ~0;
}
if (regid == GDB_REGNO_MSTATUS)
target->reg_cache->reg_list[regid].valid = true;
return value;
}
static void set_register(struct target *target, int hartid, int regid,
uint64_t value)
{
assert(hartid == 0);
/* TODO: propagate errors */
register_write(target, regid, value);
}
static int halt(struct target *target)
{
LOG_DEBUG("riscv_halt()");
jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
cache_set32(target, 0, csrsi(CSR_DCSR, DCSR_HALT));
cache_set32(target, 1, csrr(S0, CSR_MHARTID));
cache_set32(target, 2, sw(S0, ZERO, SETHALTNOT));
cache_set_jump(target, 3);
if (cache_write(target, 4, true) != ERROR_OK) {
LOG_ERROR("cache_write() failed.");
return ERROR_FAIL;
}
return ERROR_OK;
}
static int init_target(struct command_context *cmd_ctx,
struct target *target)
{
LOG_DEBUG("init");
riscv_info_t *generic_info = (riscv_info_t *) target->arch_info;
generic_info->get_register = get_register;
generic_info->set_register = set_register;
generic_info->version_specific = calloc(1, sizeof(riscv011_info_t));
if (!generic_info->version_specific)
return ERROR_FAIL;
/* Assume 32-bit until we discover the real value in examine(). */
generic_info->xlen[0] = 32;
riscv_init_registers(target);
return ERROR_OK;
}
static void deinit_target(struct target *target)
{
LOG_DEBUG("riscv_deinit_target()");
riscv_info_t *info = (riscv_info_t *) target->arch_info;
free(info->version_specific);
info->version_specific = NULL;
}
static int strict_step(struct target *target, bool announce)
{
riscv011_info_t *info = get_info(target);
LOG_DEBUG("enter");
struct breakpoint *breakpoint = target->breakpoints;
while (breakpoint) {
riscv_remove_breakpoint(target, breakpoint);
breakpoint = breakpoint->next;
}
struct watchpoint *watchpoint = target->watchpoints;
while (watchpoint) {
riscv_remove_watchpoint(target, watchpoint);
watchpoint = watchpoint->next;
}
int result = full_step(target, announce);
if (result != ERROR_OK)
return result;
breakpoint = target->breakpoints;
while (breakpoint) {
riscv_add_breakpoint(target, breakpoint);
breakpoint = breakpoint->next;
}
watchpoint = target->watchpoints;
while (watchpoint) {
riscv_add_watchpoint(target, watchpoint);
watchpoint = watchpoint->next;
}
info->need_strict_step = false;
return ERROR_OK;
}
static int step(struct target *target, int current, target_addr_t address,
int handle_breakpoints)
{
riscv011_info_t *info = get_info(target);
jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
if (!current) {
if (riscv_xlen(target) > 32) {
LOG_WARNING("Asked to resume at 32-bit PC on %d-bit target.",
riscv_xlen(target));
}
int result = register_write(target, GDB_REGNO_PC, address);
if (result != ERROR_OK)
return result;
}
if (info->need_strict_step || handle_breakpoints) {
int result = strict_step(target, true);
if (result != ERROR_OK)
return result;
} else {
return resume(target, 0, true);
}
return ERROR_OK;
}
static int examine(struct target *target)
{
/* Don't need to select dbus, since the first thing we do is read dtmcontrol. */
uint32_t dtmcontrol = dtmcontrol_scan(target, 0);
LOG_DEBUG("dtmcontrol=0x%x", dtmcontrol);
LOG_DEBUG(" addrbits=%d", get_field(dtmcontrol, DTMCONTROL_ADDRBITS));
LOG_DEBUG(" version=%d", get_field(dtmcontrol, DTMCONTROL_VERSION));
LOG_DEBUG(" idle=%d", get_field(dtmcontrol, DTMCONTROL_IDLE));
if (dtmcontrol == 0) {
LOG_ERROR("dtmcontrol is 0. Check JTAG connectivity/board power.");
return ERROR_FAIL;
}
if (get_field(dtmcontrol, DTMCONTROL_VERSION) != 0) {
LOG_ERROR("Unsupported DTM version %d. (dtmcontrol=0x%x)",
get_field(dtmcontrol, DTMCONTROL_VERSION), dtmcontrol);
return ERROR_FAIL;
}
RISCV_INFO(r);
r->hart_count = 1;
riscv011_info_t *info = get_info(target);
info->addrbits = get_field(dtmcontrol, DTMCONTROL_ADDRBITS);
info->dtmcontrol_idle = get_field(dtmcontrol, DTMCONTROL_IDLE);
if (info->dtmcontrol_idle == 0) {
/* Some old SiFive cores don't set idle but need it to be 1. */
uint32_t idcode = idcode_scan(target);
if (idcode == 0x10e31913)
info->dtmcontrol_idle = 1;
}
uint32_t dminfo = dbus_read(target, DMINFO);
LOG_DEBUG("dminfo: 0x%08x", dminfo);
LOG_DEBUG(" abussize=0x%x", get_field(dminfo, DMINFO_ABUSSIZE));
LOG_DEBUG(" serialcount=0x%x", get_field(dminfo, DMINFO_SERIALCOUNT));
LOG_DEBUG(" access128=%d", get_field(dminfo, DMINFO_ACCESS128));
LOG_DEBUG(" access64=%d", get_field(dminfo, DMINFO_ACCESS64));
LOG_DEBUG(" access32=%d", get_field(dminfo, DMINFO_ACCESS32));
LOG_DEBUG(" access16=%d", get_field(dminfo, DMINFO_ACCESS16));
LOG_DEBUG(" access8=%d", get_field(dminfo, DMINFO_ACCESS8));
LOG_DEBUG(" dramsize=0x%x", get_field(dminfo, DMINFO_DRAMSIZE));
LOG_DEBUG(" authenticated=0x%x", get_field(dminfo, DMINFO_AUTHENTICATED));
LOG_DEBUG(" authbusy=0x%x", get_field(dminfo, DMINFO_AUTHBUSY));
LOG_DEBUG(" authtype=0x%x", get_field(dminfo, DMINFO_AUTHTYPE));
LOG_DEBUG(" version=0x%x", get_field(dminfo, DMINFO_VERSION));
if (get_field(dminfo, DMINFO_VERSION) != 1) {
LOG_ERROR("OpenOCD only supports Debug Module version 1, not %d "
"(dminfo=0x%x)", get_field(dminfo, DMINFO_VERSION), dminfo);
return ERROR_FAIL;
}
info->dramsize = get_field(dminfo, DMINFO_DRAMSIZE) + 1;
if (get_field(dminfo, DMINFO_AUTHTYPE) != 0) {
LOG_ERROR("Authentication required by RISC-V core but not "
"supported by OpenOCD. dminfo=0x%x", dminfo);
return ERROR_FAIL;
}
/* Pretend this is a 32-bit system until we have found out the true value. */
r->xlen[0] = 32;
/* Figure out XLEN, and test writing all of Debug RAM while we're at it. */
cache_set32(target, 0, xori(S1, ZERO, -1));
/* 0xffffffff 0xffffffff:ffffffff 0xffffffff:ffffffff:ffffffff:ffffffff */
cache_set32(target, 1, srli(S1, S1, 31));
/* 0x00000001 0x00000001:ffffffff 0x00000001:ffffffff:ffffffff:ffffffff */
cache_set32(target, 2, sw(S1, ZERO, DEBUG_RAM_START));
cache_set32(target, 3, srli(S1, S1, 31));
/* 0x00000000 0x00000000:00000003 0x00000000:00000003:ffffffff:ffffffff */
cache_set32(target, 4, sw(S1, ZERO, DEBUG_RAM_START + 4));
cache_set_jump(target, 5);
for (unsigned i = 6; i < info->dramsize; i++)
cache_set32(target, i, i * 0x01020304);
cache_write(target, 0, false);
/* Check that we can actually read/write dram. */
if (cache_check(target) != ERROR_OK)
return ERROR_FAIL;
cache_write(target, 0, true);
cache_invalidate(target);
uint32_t word0 = cache_get32(target, 0);
uint32_t word1 = cache_get32(target, 1);
riscv_info_t *generic_info = (riscv_info_t *) target->arch_info;
if (word0 == 1 && word1 == 0) {
generic_info->xlen[0] = 32;
} else if (word0 == 0xffffffff && word1 == 3) {
generic_info->xlen[0] = 64;
} else if (word0 == 0xffffffff && word1 == 0xffffffff) {
generic_info->xlen[0] = 128;
} else {
uint32_t exception = cache_get32(target, info->dramsize-1);
LOG_ERROR("Failed to discover xlen; word0=0x%x, word1=0x%x, exception=0x%x",
word0, word1, exception);
dump_debug_ram(target);
return ERROR_FAIL;
}
LOG_DEBUG("Discovered XLEN is %d", riscv_xlen(target));
if (read_csr(target, &r->misa, CSR_MISA) != ERROR_OK) {
const unsigned old_csr_misa = 0xf10;
LOG_WARNING("Failed to read misa at 0x%x; trying 0x%x.", CSR_MISA,
old_csr_misa);
if (read_csr(target, &r->misa, old_csr_misa) != ERROR_OK) {
/* Maybe this is an old core that still has $misa at the old
* address. */
LOG_ERROR("Failed to read misa at 0x%x.", old_csr_misa);
return ERROR_FAIL;
}
}
/* Update register list to match discovered XLEN/supported extensions. */
riscv_init_registers(target);
info->never_halted = true;
int result = riscv011_poll(target);
if (result != ERROR_OK)
return result;
target_set_examined(target);
riscv_set_current_hartid(target, 0);
for (size_t i = 0; i < 32; ++i)
reg_cache_set(target, i, -1);
LOG_INFO("Examined RISCV core; XLEN=%d, misa=0x%" PRIx64,
riscv_xlen(target), r->misa);
return ERROR_OK;
}
static riscv_error_t handle_halt_routine(struct target *target)
{
riscv011_info_t *info = get_info(target);
scans_t *scans = scans_new(target, 256);
/* Read all GPRs as fast as we can, because gdb is going to ask for them
* anyway. Reading them one at a time is much slower. */
/* Write the jump back to address 1. */
scans_add_write_jump(scans, 1, false);
for (int reg = 1; reg < 32; reg++) {
if (reg == S0 || reg == S1)
continue;
/* Write store instruction. */
scans_add_write_store(scans, 0, reg, SLOT0, true);
/* Read value. */
scans_add_read(scans, SLOT0, false);
}
/* Write store of s0 at index 1. */
scans_add_write_store(scans, 1, S0, SLOT0, false);
/* Write jump at index 2. */
scans_add_write_jump(scans, 2, false);
/* Read S1 from debug RAM */
scans_add_write_load(scans, 0, S0, SLOT_LAST, true);
/* Read value. */
scans_add_read(scans, SLOT0, false);
/* Read S0 from dscratch */
unsigned int csr[] = {CSR_DSCRATCH, CSR_DPC, CSR_DCSR};
for (unsigned int i = 0; i < DIM(csr); i++) {
scans_add_write32(scans, 0, csrr(S0, csr[i]), true);
scans_add_read(scans, SLOT0, false);
}
/* Final read to get the last value out. */
scans_add_read32(scans, 4, false);
int retval = scans_execute(scans);
if (retval != ERROR_OK) {
LOG_ERROR("JTAG execute failed: %d", retval);
goto error;
}
unsigned int dbus_busy = 0;
unsigned int interrupt_set = 0;
unsigned result = 0;
uint64_t value = 0;
reg_cache_set(target, 0, 0);
/* The first scan result is the result from something old we don't care
* about. */
for (unsigned int i = 1; i < scans->next_scan && dbus_busy == 0; i++) {
dbus_status_t status = scans_get_u32(scans, i, DBUS_OP_START,
DBUS_OP_SIZE);
uint64_t data = scans_get_u64(scans, i, DBUS_DATA_START, DBUS_DATA_SIZE);
uint32_t address = scans_get_u32(scans, i, DBUS_ADDRESS_START,
info->addrbits);
switch (status) {
case DBUS_STATUS_SUCCESS:
break;
case DBUS_STATUS_FAILED:
LOG_ERROR("Debug access failed. Hardware error?");
goto error;
case DBUS_STATUS_BUSY:
dbus_busy++;
break;
default:
LOG_ERROR("Got invalid bus access status: %d", status);
return ERROR_FAIL;
}
if (data & DMCONTROL_INTERRUPT) {
interrupt_set++;
break;
}
if (address == 4 || address == 5) {
unsigned int reg;
switch (result) {
case 0:
reg = 1;
break;
case 1:
reg = 2;
break;
case 2:
reg = 3;
break;
case 3:
reg = 4;
break;
case 4:
reg = 5;
break;
case 5:
reg = 6;
break;
case 6:
reg = 7;
break;
/* S0 */
/* S1 */
case 7:
reg = 10;
break;
case 8:
reg = 11;
break;
case 9:
reg = 12;
break;
case 10:
reg = 13;
break;
case 11:
reg = 14;
break;
case 12:
reg = 15;
break;
case 13:
reg = 16;
break;
case 14:
reg = 17;
break;
case 15:
reg = 18;
break;
case 16:
reg = 19;
break;
case 17:
reg = 20;
break;
case 18:
reg = 21;
break;
case 19:
reg = 22;
break;
case 20:
reg = 23;
break;
case 21:
reg = 24;
break;
case 22:
reg = 25;
break;
case 23:
reg = 26;
break;
case 24:
reg = 27;
break;
case 25:
reg = 28;
break;
case 26:
reg = 29;
break;
case 27:
reg = 30;
break;
case 28:
reg = 31;
break;
case 29:
reg = S1;
break;
case 30:
reg = S0;
break;
case 31:
reg = CSR_DPC;
break;
case 32:
reg = CSR_DCSR;
break;
default:
assert(0);
}
if (riscv_xlen(target) == 32) {
reg_cache_set(target, reg, data & 0xffffffff);
result++;
} else if (riscv_xlen(target) == 64) {
if (address == 4) {
value = data & 0xffffffff;
} else if (address == 5) {
reg_cache_set(target, reg, ((data & 0xffffffff) << 32) | value);
value = 0;
result++;
}
}
}
}
if (dbus_busy) {
increase_dbus_busy_delay(target);
return RE_AGAIN;
}
if (interrupt_set) {
increase_interrupt_high_delay(target);
return RE_AGAIN;
}
/* TODO: get rid of those 2 variables and talk to the cache directly. */
info->dpc = reg_cache_get(target, CSR_DPC);
info->dcsr = reg_cache_get(target, CSR_DCSR);
scans = scans_delete(scans);
cache_invalidate(target);
return RE_OK;
error:
scans = scans_delete(scans);
return RE_FAIL;
}
static int handle_halt(struct target *target, bool announce)
{
riscv011_info_t *info = get_info(target);
target->state = TARGET_HALTED;
riscv_error_t re;
do {
re = handle_halt_routine(target);
} while (re == RE_AGAIN);
if (re != RE_OK) {
LOG_ERROR("handle_halt_routine failed");
return ERROR_FAIL;
}
int cause = get_field(info->dcsr, DCSR_CAUSE);
switch (cause) {
case DCSR_CAUSE_SWBP:
target->debug_reason = DBG_REASON_BREAKPOINT;
break;
case DCSR_CAUSE_HWBP:
target->debug_reason = DBG_REASON_WPTANDBKPT;
/* If we halted because of a data trigger, gdb doesn't know to do
* the disable-breakpoints-step-enable-breakpoints dance. */
info->need_strict_step = true;
break;
case DCSR_CAUSE_DEBUGINT:
target->debug_reason = DBG_REASON_DBGRQ;
break;
case DCSR_CAUSE_STEP:
target->debug_reason = DBG_REASON_SINGLESTEP;
break;
case DCSR_CAUSE_HALT:
default:
LOG_ERROR("Invalid halt cause %d in DCSR (0x%" PRIx64 ")",
cause, info->dcsr);
}
if (info->never_halted) {
info->never_halted = false;
int result = maybe_read_tselect(target);
if (result != ERROR_OK)
return result;
riscv_enumerate_triggers(target);
}
if (announce)
target_call_event_callbacks(target, TARGET_EVENT_HALTED);
const char *cause_string[] = {
"none",
"software breakpoint",
"hardware trigger",
"debug interrupt",
"step",
"halt"
};
/* This is logged to the user so that gdb will show it when a user types
* 'monitor reset init'. At that time gdb appears to have the pc cached
* still so if a user manually inspects the pc it will still have the old
* value. */
LOG_USER("halted at 0x%" PRIx64 " due to %s", info->dpc, cause_string[cause]);
return ERROR_OK;
}
static int poll_target(struct target *target, bool announce)
{
jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
/* Inhibit debug logging during poll(), which isn't usually interesting and
* just fills up the screen/logs with clutter. */
int old_debug_level = debug_level;
if (debug_level >= LOG_LVL_DEBUG)
debug_level = LOG_LVL_INFO;
bits_t bits = read_bits(target);
debug_level = old_debug_level;
if (bits.haltnot && bits.interrupt) {
target->state = TARGET_DEBUG_RUNNING;
LOG_DEBUG("debug running");
} else if (bits.haltnot && !bits.interrupt) {
if (target->state != TARGET_HALTED)
return handle_halt(target, announce);
} else if (!bits.haltnot && bits.interrupt) {
/* Target is halting. There is no state for that, so don't change anything. */
LOG_DEBUG("halting");
} else if (!bits.haltnot && !bits.interrupt) {
target->state = TARGET_RUNNING;
}
return ERROR_OK;
}
static int riscv011_poll(struct target *target)
{
return poll_target(target, true);
}
static int riscv011_resume(struct target *target, int current,
target_addr_t address, int handle_breakpoints, int debug_execution)
{
riscv011_info_t *info = get_info(target);
jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
if (!current) {
if (riscv_xlen(target) > 32) {
LOG_WARNING("Asked to resume at 32-bit PC on %d-bit target.",
riscv_xlen(target));
}
int result = register_write(target, GDB_REGNO_PC, address);
if (result != ERROR_OK)
return result;
}
if (info->need_strict_step || handle_breakpoints) {
int result = strict_step(target, false);
if (result != ERROR_OK)
return result;
}
return resume(target, debug_execution, false);
}
static int assert_reset(struct target *target)
{
riscv011_info_t *info = get_info(target);
/* TODO: Maybe what I implemented here is more like soft_reset_halt()? */
jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
/* The only assumption we can make is that the TAP was reset. */
if (wait_for_debugint_clear(target, true) != ERROR_OK) {
LOG_ERROR("Debug interrupt didn't clear.");
return ERROR_FAIL;
}
/* Not sure what we should do when there are multiple cores.
* Here just reset the single hart we're talking to. */
info->dcsr |= DCSR_EBREAKM | DCSR_EBREAKH | DCSR_EBREAKS |
DCSR_EBREAKU | DCSR_HALT;
if (target->reset_halt)
info->dcsr |= DCSR_NDRESET;
else
info->dcsr |= DCSR_FULLRESET;
dram_write32(target, 0, lw(S0, ZERO, DEBUG_RAM_START + 16), false);
dram_write32(target, 1, csrw(S0, CSR_DCSR), false);
/* We shouldn't actually need the jump because a reset should happen. */
dram_write_jump(target, 2, false);
dram_write32(target, 4, info->dcsr, true);
cache_invalidate(target);
target->state = TARGET_RESET;
return ERROR_OK;
}
static int deassert_reset(struct target *target)
{
jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
if (target->reset_halt)
return wait_for_state(target, TARGET_HALTED);
else
return wait_for_state(target, TARGET_RUNNING);
}
static int read_memory(struct target *target, target_addr_t address,
uint32_t size, uint32_t count, uint8_t *buffer)
{
jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
cache_set32(target, 0, lw(S0, ZERO, DEBUG_RAM_START + 16));
switch (size) {
case 1:
cache_set32(target, 1, lb(S1, S0, 0));
cache_set32(target, 2, sw(S1, ZERO, DEBUG_RAM_START + 16));
break;
case 2:
cache_set32(target, 1, lh(S1, S0, 0));
cache_set32(target, 2, sw(S1, ZERO, DEBUG_RAM_START + 16));
break;
case 4:
cache_set32(target, 1, lw(S1, S0, 0));
cache_set32(target, 2, sw(S1, ZERO, DEBUG_RAM_START + 16));
break;
default:
LOG_ERROR("Unsupported size: %d", size);
return ERROR_FAIL;
}
cache_set_jump(target, 3);
cache_write(target, CACHE_NO_READ, false);
riscv011_info_t *info = get_info(target);
const unsigned max_batch_size = 256;
scans_t *scans = scans_new(target, max_batch_size);
uint32_t result_value = 0x777;
uint32_t i = 0;
while (i < count + 3) {
unsigned int batch_size = MIN(count + 3 - i, max_batch_size);
scans_reset(scans);
for (unsigned int j = 0; j < batch_size; j++) {
if (i + j == count) {
/* Just insert a read so we can scan out the last value. */
scans_add_read32(scans, 4, false);
} else if (i + j >= count + 1) {
/* And check for errors. */
scans_add_read32(scans, info->dramsize-1, false);
} else {
/* Write the next address and set interrupt. */
uint32_t offset = size * (i + j);
scans_add_write32(scans, 4, address + offset, true);
}
}
int retval = scans_execute(scans);
if (retval != ERROR_OK) {
LOG_ERROR("JTAG execute failed: %d", retval);
goto error;
}
int dbus_busy = 0;
int execute_busy = 0;
for (unsigned int j = 0; j < batch_size; j++) {
dbus_status_t status = scans_get_u32(scans, j, DBUS_OP_START,
DBUS_OP_SIZE);
switch (status) {
case DBUS_STATUS_SUCCESS:
break;
case DBUS_STATUS_FAILED:
LOG_ERROR("Debug RAM write failed. Hardware error?");
goto error;
case DBUS_STATUS_BUSY:
dbus_busy++;
break;
default:
LOG_ERROR("Got invalid bus access status: %d", status);
return ERROR_FAIL;
}
uint64_t data = scans_get_u64(scans, j, DBUS_DATA_START,
DBUS_DATA_SIZE);
if (data & DMCONTROL_INTERRUPT)
execute_busy++;
if (i + j == count + 2) {
result_value = data;
} else if (i + j > 1) {
uint32_t offset = size * (i + j - 2);
switch (size) {
case 1:
buffer[offset] = data;
break;
case 2:
buffer[offset] = data;
buffer[offset+1] = data >> 8;
break;
case 4:
buffer[offset] = data;
buffer[offset+1] = data >> 8;
buffer[offset+2] = data >> 16;
buffer[offset+3] = data >> 24;
break;
}
}
LOG_DEBUG("j=%d status=%d data=%09" PRIx64, j, status, data);
}
if (dbus_busy)
increase_dbus_busy_delay(target);
if (execute_busy)
increase_interrupt_high_delay(target);
if (dbus_busy || execute_busy) {
wait_for_debugint_clear(target, false);
/* Retry. */
LOG_INFO("Retrying memory read starting from 0x%" TARGET_PRIxADDR
" with more delays", address + size * i);
} else {
i += batch_size;
}
}
if (result_value != 0) {
LOG_USER("Core got an exception (0x%x) while reading from 0x%"
TARGET_PRIxADDR, result_value, address + size * (count-1));
if (count > 1) {
LOG_USER("(It may have failed between 0x%" TARGET_PRIxADDR
" and 0x%" TARGET_PRIxADDR " as well, but we "
"didn't check then.)",
address, address + size * (count-2) + size - 1);
}
goto error;
}
scans_delete(scans);
cache_clean(target);
return ERROR_OK;
error:
scans_delete(scans);
cache_clean(target);
return ERROR_FAIL;
}
static int setup_write_memory(struct target *target, uint32_t size)
{
switch (size) {
case 1:
cache_set32(target, 0, lb(S0, ZERO, DEBUG_RAM_START + 16));
cache_set32(target, 1, sb(S0, T0, 0));
break;
case 2:
cache_set32(target, 0, lh(S0, ZERO, DEBUG_RAM_START + 16));
cache_set32(target, 1, sh(S0, T0, 0));
break;
case 4:
cache_set32(target, 0, lw(S0, ZERO, DEBUG_RAM_START + 16));
cache_set32(target, 1, sw(S0, T0, 0));
break;
default:
LOG_ERROR("Unsupported size: %d", size);
return ERROR_FAIL;
}
cache_set32(target, 2, addi(T0, T0, size));
cache_set_jump(target, 3);
cache_write(target, 4, false);
return ERROR_OK;
}
static int write_memory(struct target *target, target_addr_t address,
uint32_t size, uint32_t count, const uint8_t *buffer)
{
riscv011_info_t *info = get_info(target);
jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
/* Set up the address. */
cache_set_store(target, 0, T0, SLOT1);
cache_set_load(target, 1, T0, SLOT0);
cache_set_jump(target, 2);
cache_set(target, SLOT0, address);
if (cache_write(target, 5, true) != ERROR_OK)
return ERROR_FAIL;
uint64_t t0 = cache_get(target, SLOT1);
LOG_DEBUG("t0 is 0x%" PRIx64, t0);
if (setup_write_memory(target, size) != ERROR_OK)
return ERROR_FAIL;
const unsigned max_batch_size = 256;
scans_t *scans = scans_new(target, max_batch_size);
uint32_t result_value = 0x777;
uint32_t i = 0;
while (i < count + 2) {
unsigned int batch_size = MIN(count + 2 - i, max_batch_size);
scans_reset(scans);
for (unsigned int j = 0; j < batch_size; j++) {
if (i + j >= count) {
/* Check for an exception. */
scans_add_read32(scans, info->dramsize-1, false);
} else {
/* Write the next value and set interrupt. */
uint32_t value;
uint32_t offset = size * (i + j);
switch (size) {
case 1:
value = buffer[offset];
break;
case 2:
value = buffer[offset] |
(buffer[offset+1] << 8);
break;
case 4:
value = buffer[offset] |
((uint32_t) buffer[offset+1] << 8) |
((uint32_t) buffer[offset+2] << 16) |
((uint32_t) buffer[offset+3] << 24);
break;
default:
goto error;
}
scans_add_write32(scans, 4, value, true);
}
}
int retval = scans_execute(scans);
if (retval != ERROR_OK) {
LOG_ERROR("JTAG execute failed: %d", retval);
goto error;
}
int dbus_busy = 0;
int execute_busy = 0;
for (unsigned int j = 0; j < batch_size; j++) {
dbus_status_t status = scans_get_u32(scans, j, DBUS_OP_START,
DBUS_OP_SIZE);
switch (status) {
case DBUS_STATUS_SUCCESS:
break;
case DBUS_STATUS_FAILED:
LOG_ERROR("Debug RAM write failed. Hardware error?");
goto error;
case DBUS_STATUS_BUSY:
dbus_busy++;
break;
default:
LOG_ERROR("Got invalid bus access status: %d", status);
return ERROR_FAIL;
}
int interrupt = scans_get_u32(scans, j, DBUS_DATA_START + 33, 1);
if (interrupt)
execute_busy++;
if (i + j == count + 1)
result_value = scans_get_u32(scans, j, DBUS_DATA_START, 32);
}
if (dbus_busy)
increase_dbus_busy_delay(target);
if (execute_busy)
increase_interrupt_high_delay(target);
if (dbus_busy || execute_busy) {
wait_for_debugint_clear(target, false);
/* Retry.
* Set t0 back to what it should have been at the beginning of this
* batch. */
LOG_INFO("Retrying memory write starting from 0x%" TARGET_PRIxADDR
" with more delays", address + size * i);
cache_clean(target);
if (write_gpr(target, T0, address + size * i) != ERROR_OK)
goto error;
if (setup_write_memory(target, size) != ERROR_OK)
goto error;
} else {
i += batch_size;
}
}
if (result_value != 0) {
LOG_ERROR("Core got an exception (0x%x) while writing to 0x%"
TARGET_PRIxADDR, result_value, address + size * (count-1));
if (count > 1) {
LOG_ERROR("(It may have failed between 0x%" TARGET_PRIxADDR
" and 0x%" TARGET_PRIxADDR " as well, but we "
"didn't check then.)",
address, address + size * (count-2) + size - 1);
}
goto error;
}
cache_clean(target);
return register_write(target, T0, t0);
error:
scans_delete(scans);
cache_clean(target);
return ERROR_FAIL;
}
static int arch_state(struct target *target)
{
return ERROR_OK;
}
struct target_type riscv011_target = {
.name = "riscv",
.init_target = init_target,
.deinit_target = deinit_target,
.examine = examine,
/* poll current target status */
.poll = riscv011_poll,
.halt = halt,
.resume = riscv011_resume,
.step = step,
.assert_reset = assert_reset,
.deassert_reset = deassert_reset,
.read_memory = read_memory,
.write_memory = write_memory,
.arch_state = arch_state,
};
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