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Diffstat (limited to 'misc-utils/flash_otp_write.c')
-rw-r--r--misc-utils/flash_otp_write.c122
1 files changed, 122 insertions, 0 deletions
diff --git a/misc-utils/flash_otp_write.c b/misc-utils/flash_otp_write.c
new file mode 100644
index 0000000..111318d
--- /dev/null
+++ b/misc-utils/flash_otp_write.c
@@ -0,0 +1,122 @@
+/*
+ * flash_otp_write.c -- write One-Time-Program data
+ */
+
+#define PROGRAM_NAME "flash_otp_write"
+
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+
+#include <common.h>
+#include <mtd/mtd-user.h>
+
+ssize_t xread(int fd, void *buf, size_t count)
+{
+ ssize_t ret, done = 0;
+
+retry:
+ ret = read(fd, buf + done, count - done);
+ if (ret < 0)
+ return ret;
+
+ done += ret;
+
+ if (ret == 0 /* EOF */ || done == count)
+ return done;
+ else
+ goto retry;
+}
+
+int main(int argc,char *argv[])
+{
+ int fd, val, ret, size, wrote, len;
+ mtd_info_t mtdInfo;
+ off_t offset;
+ char *p, buf[2048];
+
+ if (argc != 4 || strcmp(argv[1], "-u")) {
+ fprintf(stderr, "Usage: %s -u <device> <offset>\n", PROGRAM_NAME);
+ fprintf(stderr, "the raw data to write should be provided on stdin\n");
+ fprintf(stderr, "CAUTION! ONCE SET TO 0, OTP DATA BITS CAN'T BE ERASED!\n");
+ return EINVAL;
+ }
+
+ fd = open(argv[2], O_WRONLY);
+ if (fd < 0) {
+ perror(argv[2]);
+ return errno;
+ }
+
+ val = MTD_OTP_USER;
+ ret = ioctl(fd, OTPSELECT, &val);
+ if (ret < 0) {
+ perror("OTPSELECT");
+ return errno;
+ }
+
+ if (ioctl(fd, MEMGETINFO, &mtdInfo)) {
+ perror("MEMGETINFO");
+ return errno;
+ }
+
+ offset = (off_t)strtoull(argv[3], &p, 0);
+ if (argv[3][0] == 0 || *p != 0) {
+ fprintf(stderr, "%s: bad offset value\n", PROGRAM_NAME);
+ return ERANGE;
+ }
+
+ if (lseek(fd, offset, SEEK_SET) == (off_t)-1) {
+ perror("lseek()");
+ return errno;
+ }
+
+ printf("Writing OTP user data on %s at offset 0x%"PRIxoff_t"\n", argv[2], offset);
+
+ if (mtd_type_is_nand_user(&mtdInfo))
+ len = mtdInfo.writesize;
+ else
+ len = 256;
+
+ if (len > sizeof(buf)) {
+ printf("huh, writesize (%d) bigger than buffer (%zu)\n",
+ len, sizeof(buf));
+ return ENOMEM;
+ }
+
+ wrote = 0;
+ while ((size = xread(0, buf, len))) {
+ if (size < 0) {
+ perror("read()");
+ return errno;
+ }
+ p = buf;
+ while (size > 0) {
+ if (mtd_type_is_nand_user(&mtdInfo)) {
+ /* Fill remain buffers with 0xff */
+ memset(buf + size, 0xff, mtdInfo.writesize - size);
+ size = mtdInfo.writesize;
+ }
+ ret = write(fd, p, size);
+ if (ret < 0) {
+ perror("write()");
+ return errno;
+ }
+ if (ret == 0) {
+ printf("write() returned 0 after writing %d bytes\n", wrote);
+ return 0;
+ }
+ p += ret;
+ wrote += ret;
+ size -= ret;
+ }
+ }
+
+ printf("Wrote %d bytes of OTP user data\n", wrote);
+ return 0;
+}