/**
* @brief Return the device size by using the sysfs
* @param sysfspath
* @return
*/
static off_t mmc_device_size_sysfs(const char *sysfspath)
{
char sizestr[16];
int rc = readsysfs(sysfspath, sizestr, sizeof(sizestr));
if (rc <= 0)
return 0;
return strtoll(sizestr, NULL, 0) * FWUP_BLOCK_SIZE;
}
int mmc_is_path_at_device_offset(const char *file_path, off_t block_offset)
{
struct stat file_st;
if (stat(file_path, &file_st) < 0)
return -1;
// Now check that the offset is in the right place by reading the sysfs file.
char start_path[64];
snprintf(start_path, sizeof(start_path), "/sys/dev/block/%d:%d/start", major(file_st.st_dev), minor(file_st.st_dev));
char start[16];
if (readsysfs(start_path, start, sizeof(start)) <= 0)
return -1;
off_t start_offset = strtoull(start, NULL, 0);
return start_offset == block_offset ? 1 : 0;
}
int
setsysfs(char *dir, char *entry, char *value)
{
char filename[PATH_MAX];
char *oldvalue;
int fd, ret = 0;
if (dir == NULL)
snprintf(filename, PATH_MAX, "%s/%s", MICSYSFSDIR, entry);
else
snprintf(filename, PATH_MAX, "%s/%s/%s",
MICSYSFSDIR, dir, entry);
oldvalue = readsysfs(dir, entry);
fd = open(filename, O_RDWR);
if (fd < 0) {
ret = errno;
mpsslog("Failed to open sysfs entry '%s': %s\n",
filename, strerror(errno));
goto done;
}
if (!oldvalue || strcmp(value, oldvalue)) {
if (write(fd, value, strlen(value)) < 0) {
ret = errno;
mpsslog("Failed to write new sysfs entry '%s': %s\n",
filename, strerror(errno));
}
}
close(fd);
done:
if (oldvalue)
free(oldvalue);
return ret;
}