mspdebug/bsl.c

365 lines
7.8 KiB
C

/* MSPDebug - debugging tool for the eZ430
* Copyright (C) 2009, 2010 Daniel Beer
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <stdint.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <unistd.h>
#include "bsl.h"
#include "util.h"
#include "fet_error.h"
struct bsl_device {
struct device base;
int serial_fd;
uint8_t reply_buf[256];
int reply_len;
};
#define DATA_HDR 0x80
#define DATA_ACK 0x90
#define DATA_NAK 0xA0
static int bsl_ack(struct bsl_device *dev)
{
uint8_t reply;
if (read_with_timeout(dev->serial_fd, &reply, 1) < 0) {
fprintf(stderr, "bsl: failed to receive reply\n");
return -1;
}
if (reply == DATA_NAK) {
fprintf(stderr, "bsl: received NAK\n");
return -1;
}
if (reply != DATA_ACK) {
fprintf(stderr, "bsl: bad ack character: %x\n", reply);
return -1;
}
return 0;
}
static int bsl_sync(struct bsl_device *dev)
{
static const uint8_t c = DATA_HDR;
int tries = 2;
if (tcflush(dev->serial_fd, TCIFLUSH) < 0) {
perror("bsl: tcflush");
return -1;
}
while (tries--)
if (!(write_all(dev->serial_fd, &c, 1) || bsl_ack(dev)))
return 0;
fprintf(stderr, "bsl: sync failed\n");
return -1;
}
static int send_command(struct bsl_device *dev,
int code, uint16_t addr,
const uint8_t *data, int len)
{
uint8_t pktbuf[256];
uint8_t cklow = 0xff;
uint8_t ckhigh = 0xff;
int pktlen = data ? len + 4 : 4;
int i;
if (pktlen + 6 > sizeof(pktbuf)) {
fprintf(stderr, "bsl: payload too large: %d\n", len);
return -1;
}
pktbuf[0] = DATA_HDR;
pktbuf[1] = code;
pktbuf[2] = pktlen;
pktbuf[3] = pktlen;
pktbuf[4] = addr & 0xff;
pktbuf[5] = addr >> 8;
pktbuf[6] = len & 0xff;
pktbuf[7] = len >> 8;
if (data)
memcpy(pktbuf + 8, data, len);
for (i = 0; i < pktlen + 4; i += 2)
cklow ^= pktbuf[i];
for (i = 1; i < pktlen + 4; i += 2)
ckhigh ^= pktbuf[i];
pktbuf[pktlen + 4] = cklow;
pktbuf[pktlen + 5] = ckhigh;
return write_all(dev->serial_fd, pktbuf, pktlen + 6);
}
static int verify_checksum(struct bsl_device *dev)
{
uint8_t cklow = 0xff;
uint8_t ckhigh = 0xff;
int i;
for (i = 0; i < dev->reply_len; i += 2)
cklow ^= dev->reply_buf[i];
for (i = 1; i < dev->reply_len; i += 2)
ckhigh ^= dev->reply_buf[i];
if (cklow || ckhigh) {
fprintf(stderr, "bsl: checksum invalid (%02x %02x)\n",
cklow, ckhigh);
return -1;
}
return 0;
}
static int fetch_reply(struct bsl_device *dev)
{
dev->reply_len = 0;
for (;;) {
int r = read_with_timeout(dev->serial_fd,
dev->reply_buf + dev->reply_len,
sizeof(dev->reply_buf) -
dev->reply_len);
if (r < 0)
return -1;
dev->reply_len += r;
if (dev->reply_buf[0] == DATA_ACK) {
return 0;
} else if (dev->reply_buf[0] == DATA_HDR) {
if (dev->reply_len >= 6 &&
dev->reply_len == dev->reply_buf[2] + 6)
return verify_checksum(dev);
} else if (dev->reply_buf[0] == DATA_NAK) {
fprintf(stderr, "bsl: received NAK\n");
return -1;
} else {
fprintf(stderr, "bsl: unknown reply type: %02x\n",
dev->reply_buf[0]);
return -1;
}
if (dev->reply_len >= sizeof(dev->reply_buf)) {
fprintf(stderr, "bsl: reply buffer overflow\n");
return -1;
}
}
}
static int bsl_xfer(struct bsl_device *dev,
int command_code, uint16_t addr, const uint8_t *txdata,
int len)
{
if (bsl_sync(dev) < 0 ||
send_command(dev, command_code, addr, txdata, len) < 0 ||
fetch_reply(dev) < 0) {
fprintf(stderr, "bsl: failed on command 0x%02x "
"(addr = 0x%04x, len = 0x%04x)\n",
command_code, addr, len);
return -1;
}
return 0;
}
#define CMD_TX_DATA 0x38
#define CMD_ERASE 0x39
#define CMD_RX_DATA 0x3a
#define CMD_RESET 0x3b
static void bsl_destroy(device_t dev_base)
{
struct bsl_device *dev = (struct bsl_device *)dev_base;
bsl_xfer(dev, CMD_RESET, 0, NULL, 0);
close(dev->serial_fd);
free(dev);
}
static int bsl_ctl(device_t dev_base, device_ctl_t type)
{
fprintf(stderr, "bsl: CPU control is not implemented\n");
return -1;
}
static device_status_t bsl_poll(device_t dev_base)
{
return DEVICE_STATUS_HALTED;
}
static int bsl_breakpoint(device_t dev_base, int enabled, uint16_t addr)
{
fprintf(stderr, "bsl: breakpoints are not implemented\n");
return -1;
}
static int bsl_getregs(device_t dev_base, uint16_t *regs)
{
fprintf(stderr, "bsl: register fetch is not implemented\n");
return -1;
}
static int bsl_setregs(device_t dev_base, const uint16_t *regs)
{
fprintf(stderr, "bsl: register store is not implemented\n");
return -1;
}
static int bsl_writemem(device_t dev_base,
uint16_t addr, const uint8_t *mem, int len)
{
fprintf(stderr, "bsl: memory write is not implemented\n");
return -1;
}
static int bsl_readmem(device_t dev_base,
uint16_t addr, uint8_t *mem, int len)
{
struct bsl_device *dev = (struct bsl_device *)dev_base;
while (len) {
int count = len;
if (count > 128)
count = 128;
if (bsl_xfer(dev, CMD_TX_DATA, addr, NULL, count) < 0) {
fprintf(stderr, "bsl: failed to read memory\n");
return -1;
}
if (count > dev->reply_buf[2])
count = dev->reply_buf[2];
memcpy(mem, dev->reply_buf + 4, count);
mem += count;
len -= count;
}
return 0;
}
static int enter_via_fet(struct bsl_device *dev)
{
uint8_t buf[16];
uint8_t *data = buf;
int len = 8;
/* Enter bootloader command */
if (write_all(dev->serial_fd,
(uint8_t *)"\x7e\x24\x01\x9d\x5a\x7e", 6)) {
fprintf(stderr, "bsl: couldn't write bootloader transition "
"command\n");
return -1;
}
/* Wait for reply */
while (len) {
int r = read_with_timeout(dev->serial_fd, data, len);
if (r < 0) {
fprintf(stderr, "bsl: couldn't read bootloader "
"transition acknowledgement\n");
return -1;
}
data += r;
len -= r;
}
/* Check that it's what we expect */
if (memcmp(buf, "\x06\x00\x24\x00\x00\x00\x61\x01", 8)) {
fprintf(stderr, "bsl: bootloader start returned error "
"%d (%s)\n", buf[5], fet_error(buf[5]));
return -1;
}
return 0;
}
device_t bsl_open(const char *device)
{
struct bsl_device *dev = malloc(sizeof(*dev));
if (!dev) {
perror("bsl: can't allocate memory");
return NULL;
}
dev->base.destroy = bsl_destroy;
dev->base.readmem = bsl_readmem;
dev->base.writemem = bsl_writemem;
dev->base.getregs = bsl_getregs;
dev->base.setregs = bsl_setregs;
dev->base.breakpoint = bsl_breakpoint;
dev->base.ctl = bsl_ctl;
dev->base.poll = bsl_poll;
dev->serial_fd = open_serial(device, B460800);
if (dev->serial_fd < 0) {
fprintf(stderr, "bsl: can't open %s: %s\n",
device, strerror(errno));
free(dev);
return NULL;
}
if (enter_via_fet(dev) < 0)
return NULL;
usleep(500000);
/* Show chip info */
if (bsl_xfer(dev, CMD_TX_DATA, 0xff0, NULL, 0x10) < 0) {
fprintf(stderr, "bsl: failed to read chip info\n");
goto fail;
}
if (dev->reply_len < 0x16) {
fprintf(stderr, "bsl: missing chip info\n");
goto fail;
}
printf("Device ID: 0x%02x%02x\n",
dev->reply_buf[4], dev->reply_buf[5]);
printf("BSL version is %x.%02x\n", dev->reply_buf[14],
dev->reply_buf[15]);
return (device_t)dev;
fail:
close(dev->serial_fd);
free(dev);
return NULL;
}