Implements the alternative boot operation for eMMCs.
Note the limitations of the help.
This is mostly useful for testing purposes if you set
up the boot partition configuration correctly.
Usage:
$ sudo dd if=/dev/mmcblk2boot0 of=bootdatammcblk count=2
2+0 records in
2+0 records out
1024 bytes (1.0 kB, 1.0 KiB) copied, 0.00482308 s, 212 kB/s
$ sudo ./mmc boot_operation bootdata 2 /dev/mmcblk2
$ diff -s bootdata bootdatammcblk
Files bootdata and bootdatammcblk are identical
Signed-off-by: Christian Loehle <cloehle@xxxxxxxxxxxxxx>
---
mmc.c | 12 +++++++++
mmc.h | 1 +
mmc_cmds.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
mmc_cmds.h | 1 +
4 files changed, 90 insertions(+)
diff --git a/mmc.c b/mmc.c
index 170ee39..f328585 100644
--- a/mmc.c
+++ b/mmc.c
@@ -255,6 +255,18 @@ static struct Command commands[] = {
"Issues a CMD0 GO_PRE_IDLE",
NULL
},
+ { do_alt_boot_op, -1,
+ "boot_operation", "<boot_data_file> <boot_blocks> <device>\n"
+ "Does the alternative boot operation and writes the specified starting blocks of boot data into the requested file.\n\n"
+ "Note some limitations\n:"
+ "1. The boot operation must be configured, e.g. for legacy speed:\n"
+ "mmc-utils bootbus set single_backward retain x8 /dev/mmcblk2\n"
+ "mmc-utils bootpart enable 1 0 /dev/mmcblk2\n"
+ "2. The MMC must currently be running at the bus mode that is configured for the boot operation (HS200 and HS400 not supported at all).\n"
+ "3. Most hosts cannot do transfers of the typical size of the boot partition, adjust <boot_blocks> accordingly.\n"
+ "4. The MMC will perform a soft reset, if your system cannot handle that do not use the boot operation from mmc-utils.\n",
+ NULL
+ },
{ 0, 0, 0, 0 }
};
diff --git a/mmc.h b/mmc.h
index 6511dbc..98fad16 100644
--- a/mmc.h
+++ b/mmc.h
@@ -24,6 +24,7 @@
#define MMC_GO_IDLE_STATE 0 /* bc */
#define MMC_GO_IDLE_STATE_ARG 0x0
#define MMC_GO_PRE_IDLE_STATE_ARG 0xF0F0F0F0
+#define MMC_BOOT_INITIATION_ARG 0xFFFFFFFA
#define MMC_SWITCH 6 /* ac [31:0] See below R1b */
#define MMC_SEND_EXT_CSD 8 /* adtc R1 */
#define MMC_SEND_STATUS 13 /* ac [31:16] RCA R1 */
diff --git a/mmc_cmds.c b/mmc_cmds.c
index 3db17e1..1da61d4 100644
--- a/mmc_cmds.c
+++ b/mmc_cmds.c
@@ -3101,3 +3101,79 @@ int do_preidle(int nargs, char **argv)
return 0;
}
+
+int do_alt_boot_op(int nargs, char **argv)
+{
+ int fd, ret, boot_data_fd;
+ char *device, *boot_data_file;
+ struct mmc_ioc_multi_cmd *mioc;
+ __u8 ext_csd[512];
+ __u8 *boot_buf;
+ unsigned int boot_blocks, ext_csd_boot_size;
+
+ if (nargs != 4) {
+ fprintf(stderr, "Usage: mmc boot_op <boot_data_file> <boot_blocks> </path/to/mmcblkX>\n");
+ exit(1);
+ }
+ boot_data_file = argv[1];
+ boot_blocks = strtol(argv[2], NULL, 10);
+ device = argv[3];
+
+ fd = open(device, O_RDWR);
+ if (fd < 0) {
+ perror("open device");
+ exit(1);
+ }
+ boot_data_fd = open(boot_data_file, O_WRONLY | O_CREAT, 0644);
+ if (boot_data_fd < 0) {
+ perror("open boot data file");
+ exit(1);
+ }
+
+ ret = read_extcsd(fd, ext_csd);
+ if (ret) {
+ perror("read extcsd");
+ exit(1);
+ }
+ ext_csd_boot_size = ext_csd[226] * 128 * 1024;
+ if (boot_blocks * 512 > ext_csd_boot_size) {
+ perror("Requested boot size bigger than boot partition");
+ exit(1);
+ }
+
+ boot_buf = calloc(1, sizeof(__u8) * boot_blocks * 512);
+ mioc = calloc(1, sizeof(struct mmc_ioc_multi_cmd) +
+ 2 * sizeof(struct mmc_ioc_cmd));
+ if (!mioc || !boot_buf) {
+ perror("Failed to allocate memory");
+ return -ENOMEM;
+ }
+
+ mioc->num_of_cmds = 2;
+ mioc->cmds[0].opcode = MMC_GO_IDLE_STATE;
+ mioc->cmds[0].arg = MMC_GO_PRE_IDLE_STATE_ARG;
+ mioc->cmds[0].flags = MMC_RSP_NONE | MMC_CMD_AC;
+ mioc->cmds[0].write_flag = 0;
+
+ mioc->cmds[1].opcode = MMC_GO_IDLE_STATE;
+ mioc->cmds[1].arg = MMC_BOOT_INITIATION_ARG;
+ mioc->cmds[1].flags = MMC_RSP_NONE | MMC_CMD_ADTC;
+ mioc->cmds[1].write_flag = 0;
+ mioc->cmds[1].blksz = 512;
+ mioc->cmds[1].blocks = boot_blocks;
+ /* Access time of boot part differs wildly, spec mandates 1s */
+ mioc->cmds[1].data_timeout_ns = 2 * 1000 * 1000 * 1000;
+ mmc_ioc_cmd_set_data(mioc->cmds[1], boot_buf);
+
+ ret = ioctl(fd, MMC_IOC_MULTI_CMD, mioc);
+ if (ret)
+ perror("multi-cmd ioctl error %d\n", ret);
+ close(fd);
+
+ ret = DO_IO(write, boot_data_fd, boot_buf, boot_blocks * 512);
+ if (ret < 0) {
+ perror("Write error\n");
+ exit(1);
+ }
+ return 0;
+}
diff --git a/mmc_cmds.h b/mmc_cmds.h
index faab362..5f2bef1 100644
--- a/mmc_cmds.h
+++ b/mmc_cmds.h
@@ -49,3 +49,4 @@ int do_erase(int nargs, char **argv);
int do_general_cmd_read(int nargs, char **argv);
int do_softreset(int nargs, char **argv);
int do_preidle(int nargs, char **argv);
+int do_alt_boot_op(int nargs, char **argv);
--
2.37.3
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