This adds a new option to enable the boot from eMMC
by writing to the 179 ext_csd register.
The example below shows as to enable the mmcblk0boot0
partition and also set/reset the ACK bit).
$ ./mmc booten 1 1 /dev/mmcblk0boot0
$ ./mmc extcsd read /dev/mmcblk0boot0 | grep PARTITION_CON
Boot configuration bytes [PARTITION_CONFIG: 0x49]
Reported-by: Youssef TRIKI <youssef.triki@xxxxxx>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
---
mmc.c | 5 ++++
mmc.h | 6 +++++
mmc_cmds.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
mmc_cmds.h | 1 +
4 files changed, 74 insertions(+), 0 deletions(-)
diff --git a/mmc.c b/mmc.c
index c27fc24..c295885 100644
--- a/mmc.c
+++ b/mmc.c
@@ -65,6 +65,11 @@ static struct Command commands[] = {
"Set the eMMC writeprotect status of <device>.",
NULL
},
+ { do_write_boot_en, -3,
+ "booten", "<boot_partition> " "<ack> " "<device>\n"
+ "Enable the boot partition for the <device>.",
+ NULL
+ },
{ 0, 0, 0, 0 }
};
diff --git a/mmc.h b/mmc.h
index 3af36f1..cedfae1 100644
--- a/mmc.h
+++ b/mmc.h
@@ -35,6 +35,7 @@
#define EXT_CSD_PART_SWITCH_TIME 199
#define EXT_CSD_BOOT_CFG 179
#define EXT_CSD_BOOT_WP 173
+#define EXT_CSD_PART_CONFIG 179
/*
* EXT_CSD field definitions
@@ -52,6 +53,11 @@
#define EXT_CSD_BOOT_CFG_ACK (1<<6)
#define EXT_CSD_BOOT_CFG_EN (0x38)
#define EXT_CSD_BOOT_CFG_ACC (0x03)
+#define EXT_CSD_PART_CONFIG_ACC_MASK (0x7)
+#define EXT_CSD_PART_CONFIG_ACC_BOOT0 (0x1)
+#define EXT_CSD_PART_CONFIG_ACC_BOOT1 (0x2)
+#define EXT_CSD_PART_CONFIG_ACC_USER_AREA (0x7)
+#define EXT_CSD_PART_CONFIG_ACC_ACK (0x40)
/* From kernel linux/mmc/core.h */
#define MMC_RSP_PRESENT (1 << 0)
diff --git a/mmc_cmds.c b/mmc_cmds.c
index 4562cef..f588b17 100644
--- a/mmc_cmds.c
+++ b/mmc_cmds.c
@@ -168,6 +168,68 @@ int do_writeprotect_set(int nargs, char **argv)
return ret;
}
+int do_write_boot_en(int nargs, char **argv)
+{
+ __u8 ext_csd[512];
+ __u8 value = 0;
+ int fd, ret;
+ char *device;
+ int boot_area, ack;
+
+ CHECK(nargs != 4, "Usage: mmc booten <partition_number> "
+ "<ack> </path/to/mmcblkX>\n", exit(1));
+
+ boot_area = strtol(argv[1], NULL, 10);
+ ack = strtol(argv[2], NULL, 10);
+ device = argv[3];
+
+ 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);
+ }
+
+ value = ext_csd[EXT_CSD_PART_CONFIG];
+
+ switch (boot_area) {
+ case EXT_CSD_PART_CONFIG_ACC_BOOT0:
+ value |= (1 << 3);
+ value &= ~(3 << 4);
+ break;
+ case EXT_CSD_PART_CONFIG_ACC_BOOT1:
+ value |= (1 << 4);
+ value &= ~(1 << 3);
+ value &= ~(1 << 5);
+ break;
+ case EXT_CSD_PART_CONFIG_ACC_USER_AREA:
+ value |= (boot_area << 3);
+ break;
+ default:
+ fprintf(stderr, "Cannot enable the boot area\n");
+ exit(1);
+ }
+ if (ack)
+ value |= EXT_CSD_PART_CONFIG_ACC_ACK;
+ else
+ value &= ~EXT_CSD_PART_CONFIG_ACC_ACK;
+
+ ret = write_extcsd_value(fd, EXT_CSD_PART_CONFIG, value);
+ if (ret) {
+ fprintf(stderr, "Could not write 0x%02x to "
+ "EXT_CSD[%d] in %s\n",
+ value, EXT_CSD_PART_CONFIG, device);
+ exit(1);
+ }
+ return ret;
+}
+
+
int do_read_extcsd(int nargs, char **argv)
{
__u8 ext_csd[512], ext_csd_rev, reg;
diff --git a/mmc_cmds.h b/mmc_cmds.h
index 66e9acb..264409a 100644
--- a/mmc_cmds.h
+++ b/mmc_cmds.h
@@ -19,3 +19,4 @@ int do_read_extcsd(int nargs, char **argv);
int do_write_extcsd(int nargs, char **argv);
int do_writeprotect_get(int nargs, char **argv);
int do_writeprotect_set(int nargs, char **argv);
+int do_write_boot_en(int nargs, char **argv);
--
1.7.4.4
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