#include <fcntl.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <libgen.h>
#include <unistd.h>
#include <getopt.h>
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#define EC_SPACE_SIZE 256
#define SYSFS_PATH "/sys/kernel/debug/ec/ec0/io"
static int read_mode = -1;
static int sleep_time;
static int write_byte_offset = -1;
static int read_byte_offset = -1;
static uint8_t write_value = -1;
void usage(char progname[], int exit_status)
{
printf("Usage:\n");
printf("1) %s -r [-s sleep]\n", basename(progname));
printf("2) %s -b byte_offset\n", basename(progname));
printf("3) %s -w byte_offset -v value\n\n", basename(progname));
puts("\t-r [-s sleep] : Dump EC registers");
puts("\t If sleep is given, sleep x seconds,");
puts("\t re-read EC registers and show changes");
puts("\t-b offset : Read value at byte_offset (in hex)");
puts("\t-w offset -v value : Write value at byte_offset");
puts("\t-h : Print this help\n\n");
puts("Offsets and values are in hexadecimal number system.");
puts("The offset and value must be between 0 and 0xff.");
exit(exit_status);
}
void parse_opts(int argc, char *argv[])
{
int c;
while ((c = getopt(argc, argv, "rs:b:w:v:h")) != -1) {
switch (c) {
case 'r':
if (read_mode != -1)
usage(argv[0], EXIT_FAILURE);
read_mode = 1;
break;
case 's':
if (read_mode != -1 && read_mode != 1)
usage(argv[0], EXIT_FAILURE);
sleep_time = atoi(optarg);
if (sleep_time <= 0) {
sleep_time = 0;
usage(argv[0], EXIT_FAILURE);
printf("Bad sleep time: %s\n", optarg);
}
break;
case 'b':
if (read_mode != -1)
usage(argv[0], EXIT_FAILURE);
read_mode = 1;
read_byte_offset = strtoul(optarg, NULL, 16);
break;
case 'w':
if (read_mode != -1)
usage(argv[0], EXIT_FAILURE);
read_mode = 0;
write_byte_offset = strtoul(optarg, NULL, 16);
break;
case 'v':
write_value = strtoul(optarg, NULL, 16);
break;
case 'h':
usage(argv[0], EXIT_SUCCESS);
default:
fprintf(stderr, "Unknown option!\n");
usage(argv[0], EXIT_FAILURE);
}
}
if (read_mode == 0) {
if (write_byte_offset < 0 ||
write_byte_offset >= EC_SPACE_SIZE) {
fprintf(stderr, "Wrong byte offset 0x%.2x, valid: "
"[0-0x%.2x]\n",
write_byte_offset, EC_SPACE_SIZE - 1);
usage(argv[0], EXIT_FAILURE);
}
if (write_value < 0 ||
write_value >= 255) {
fprintf(stderr, "Wrong byte offset 0x%.2x, valid:"
"[0-0xff]\n", write_byte_offset);
usage(argv[0], EXIT_FAILURE);
}
}
if (read_mode == 1 && read_byte_offset != -1) {
if (read_byte_offset < -1 ||
read_byte_offset >= EC_SPACE_SIZE) {
fprintf(stderr, "Wrong byte offset 0x%.2x, valid: "
"[0-0x%.2x]\n",
read_byte_offset, EC_SPACE_SIZE - 1);
usage(argv[0], EXIT_FAILURE);
}
}
}
void dump_ec(int fd)
{
char buf[EC_SPACE_SIZE];
char buf2[EC_SPACE_SIZE];
int byte_off, bytes_read;
bytes_read = read(fd, buf, EC_SPACE_SIZE);
if (bytes_read == -1)
err(EXIT_FAILURE, "Could not read from %s\n", SYSFS_PATH);
if (bytes_read != EC_SPACE_SIZE)
fprintf(stderr, "Could only read %d bytes\n", bytes_read);
printf(" 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F");
for (byte_off = 0; byte_off < bytes_read; byte_off++) {
if ((byte_off % 16) == 0)
printf("\n%.2X: ", byte_off);
printf(" %.2x ", (uint8_t)buf[byte_off]);
}
printf("\n");
if (!sleep_time)
return;
printf("\n");
lseek(fd, 0, SEEK_SET);
sleep(sleep_time);
bytes_read = read(fd, buf2, EC_SPACE_SIZE);
if (bytes_read == -1)
err(EXIT_FAILURE, "Could not read from %s\n", SYSFS_PATH);
if (bytes_read != EC_SPACE_SIZE)
fprintf(stderr, "Could only read %d bytes\n", bytes_read);
printf(" 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F");
for (byte_off = 0; byte_off < bytes_read; byte_off++) {
if ((byte_off % 16) == 0)
printf("\n%.2X: ", byte_off);
if (buf[byte_off] == buf2[byte_off])
printf(" %.2x ", (uint8_t)buf2[byte_off]);
else
printf("*%.2x ", (uint8_t)buf2[byte_off]);
}
printf("\n");
}
void read_ec_val(int fd, int byte_offset)
{
uint8_t buf;
int error;
error = lseek(fd, byte_offset, SEEK_SET);
if (error != byte_offset)
err(EXIT_FAILURE, "Cannot set offset to 0x%.2x", byte_offset);
error = read(fd, &buf, 1);
if (error != 1)
err(EXIT_FAILURE, "Could not read byte 0x%.2x from %s\n",
byte_offset, SYSFS_PATH);
printf("0x%.2x\n", buf);
return;
}
void write_ec_val(int fd, int byte_offset, uint8_t value)
{
int error;
error = lseek(fd, byte_offset, SEEK_SET);
if (error != byte_offset)
err(EXIT_FAILURE, "Cannot set offset to 0x%.2x", byte_offset);
error = write(fd, &value, 1);
if (error != 1)
err(EXIT_FAILURE, "Cannot write value 0x%.2x to offset 0x%.2x",
value, byte_offset);
}
int main(int argc, char *argv[])
{
int file_mode = O_RDONLY;
int fd;
parse_opts(argc, argv);
if (read_mode == 0)
file_mode = O_WRONLY;
else if (read_mode == 1)
file_mode = O_RDONLY;
else
usage(argv[0], EXIT_FAILURE);
fd = open(SYSFS_PATH, file_mode);
if (fd == -1)
err(EXIT_FAILURE, "%s", SYSFS_PATH);
if (read_mode)
if (read_byte_offset == -1)
dump_ec(fd);
else if (read_byte_offset < 0 ||
read_byte_offset >= EC_SPACE_SIZE)
usage(argv[0], EXIT_FAILURE);
else
read_ec_val(fd, read_byte_offset);
else
write_ec_val(fd, write_byte_offset, write_value);
close(fd);
exit(EXIT_SUCCESS);
}
