Add support for disabling 512B emulation
In this patch, we add a utility to disable emulation mode in eMMC-4.5.
This is done to increase the data sector size to 4KB.
Signed-off-by: Saugata Das <saugata.das@linaro.org>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/mmc_cmds.c b/mmc_cmds.c
index 525bb5e..90619db 100644
--- a/mmc_cmds.c
+++ b/mmc_cmds.c
@@ -170,6 +170,50 @@
return ret;
}
+int do_disable_512B_emulation(int nargs, char **argv)
+{
+ __u8 ext_csd[512], native_sector_size, data_sector_size, wr_rel_param;
+ int fd, ret;
+ char *device;
+
+ CHECK(nargs != 2, "Usage: mmc disable 512B emulation </path/to/mmcblkX>\n", exit(1));
+ device = argv[1];
+
+ fd = open(device, O_RDWR);
+ if (fd < 0) {
+ perror("open");
+ exit(1);
+ }
+
+ ret = read_extcsd(fd, ext_csd);
+ if (ret) {
+ fprintf(stderr, "Could not read EXT_CSD from %s\n", device);
+ exit(1);
+ }
+
+ wr_rel_param = ext_csd[EXT_CSD_WR_REL_PARAM];
+ native_sector_size = ext_csd[EXT_CSD_NATIVE_SECTOR_SIZE];
+ data_sector_size = ext_csd[EXT_CSD_DATA_SECTOR_SIZE];
+
+ if (native_sector_size && !data_sector_size &&
+ (wr_rel_param & EN_REL_WR)) {
+ ret = write_extcsd_value(fd, EXT_CSD_USE_NATIVE_SECTOR, 1);
+
+ if (ret) {
+ fprintf(stderr, "Could not write 0x%02x to EXT_CSD[%d] in %s\n",
+ 1, EXT_CSD_BOOT_WP, device);
+ exit(1);
+ }
+ printf("MMC disable 512B emulation successful. Now reset the device to switch to 4KB native sector mode.\n");
+ } else if (native_sector_size && data_sector_size) {
+ printf("MMC 512B emulation mode is already disabled; doing nothing.\n");
+ } else {
+ printf("MMC does not support disabling 512B emulation mode.\n");
+ }
+
+ return ret;
+}
+
int do_write_boot_en(int nargs, char **argv)
{
__u8 ext_csd[512];
@@ -236,7 +280,6 @@
return ret;
}
-
int do_read_extcsd(int nargs, char **argv)
{
__u8 ext_csd[512], ext_csd_rev, reg;