+ Avri
On Mon, 16 Mar 2020 at 21:22, Julius Werner <jwerner@xxxxxxxxxxxx> wrote:
>
> This patch updates 'mmc writeprotect boot set' with a few more optional
> parameters, so that it can be used to enable permanent write-protection
> and so that the two boot partitions can be protected independently. It
> also splits protection information output by 'mmc writeprotect boot get'
> by partition.
>
> (Note: eMMC boot partitions are named "Area 1" and "Area 2" by the eMMC
> spec, but mmcblk0boot0 and mmcblk0boot1 by Linux. To avoid confusion
> between the two numbering schemes, this patch uses 0 and 1 throughout,
> even when defining EXT_CSD register bits.)
>
> Signed-off-by: Julius Werner <jwerner@xxxxxxxxxxxx>
Applied to git.kernel.org/pub/scm/utils/mmc/mmc-utils.git master, thanks!
Kind regards
Uffe
> ---
> mmc.c | 17 ++++++++++---
> mmc.h | 11 ++++++++
> mmc_cmds.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++------
> 3 files changed, 91 insertions(+), 11 deletions(-)
>
> diff --git a/mmc.c b/mmc.c
> index 50c9c9e..9e46072 100644
> --- a/mmc.c
> +++ b/mmc.c
> @@ -64,9 +64,20 @@ static struct Command commands[] = {
> NULL
> },
> { do_writeprotect_boot_set, -1,
> - "writeprotect boot set", "<device>\n"
> - "Set the boot partitions write protect status for <device>.\nThis sets the eMMC boot partitions to be write-protected until\nthe next boot.",
> - NULL
> + "writeprotect boot set",
> +#ifdef DANGEROUS_COMMANDS_ENABLED
> + "[-p] "
> +#endif /* DANGEROUS_COMMANDS_ENABLED */
> + "<device> [<number>]\n"
> + "Set the boot partition write protect status for <device>.\n"
> + "If <number> is passed (0 or 1), only protect that particular\n"
> + "eMMC boot partition, otherwise protect both. It will be\n"
> + "write-protected until the next boot.\n"
> +#ifdef DANGEROUS_COMMANDS_ENABLED
> + " -p Protect partition permanently instead.\n"
> + " NOTE! -p is a one-time programmable (unreversible) change.\n"
> +#endif /* DANGEROUS_COMMANDS_ENABLED */
> + , NULL
> },
> { do_writeprotect_user_set, -4,
> "writeprotect user set", "<type>" "<start block>" "<blocks>" "<device>\n"
> diff --git a/mmc.h b/mmc.h
> index 648fb26..e3cb621 100644
> --- a/mmc.h
> +++ b/mmc.h
> @@ -74,6 +74,7 @@
> #define EXT_CSD_PART_CONFIG 179
> #define EXT_CSD_BOOT_BUS_CONDITIONS 177
> #define EXT_CSD_ERASE_GROUP_DEF 175
> +#define EXT_CSD_BOOT_WP_STATUS 174
> #define EXT_CSD_BOOT_WP 173
> #define EXT_CSD_USER_WP 171
> #define EXT_CSD_FW_CONFIG 169 /* R/W */
> @@ -143,9 +144,19 @@
> #define EXT_CSD_HPI_SUPP (1<<0)
> #define EXT_CSD_HPI_IMPL (1<<1)
> #define EXT_CSD_CMD_SET_NORMAL (1<<0)
> +/* NOTE: The eMMC spec calls the partitions "Area 1" and "Area 2", but Linux
> + * calls them mmcblk0boot0 and mmcblk0boot1. To avoid confustion between the two
> + * numbering schemes, this tool uses 0 and 1 throughout. */
> +#define EXT_CSD_BOOT_WP_S_AREA_1_PERM (0x08)
> +#define EXT_CSD_BOOT_WP_S_AREA_1_PWR (0x04)
> +#define EXT_CSD_BOOT_WP_S_AREA_0_PERM (0x02)
> +#define EXT_CSD_BOOT_WP_S_AREA_0_PWR (0x01)
> +#define EXT_CSD_BOOT_WP_B_SEC_WP_SEL (0x80)
> #define EXT_CSD_BOOT_WP_B_PWR_WP_DIS (0x40)
> #define EXT_CSD_BOOT_WP_B_PERM_WP_DIS (0x10)
> +#define EXT_CSD_BOOT_WP_B_PERM_WP_SEC_SEL (0x08)
> #define EXT_CSD_BOOT_WP_B_PERM_WP_EN (0x04)
> +#define EXT_CSD_BOOT_WP_B_PWR_WP_SEC_SEL (0x02)
> #define EXT_CSD_BOOT_WP_B_PWR_WP_EN (0x01)
> #define EXT_CSD_BOOT_INFO_HS_MODE (1<<2)
> #define EXT_CSD_BOOT_INFO_DDR_DDR (1<<1)
> diff --git a/mmc_cmds.c b/mmc_cmds.c
> index fb37189..c230127 100644
> --- a/mmc_cmds.c
> +++ b/mmc_cmds.c
> @@ -202,11 +202,19 @@ static void print_writeprotect_boot_status(__u8 *ext_csd)
> else
> printf("possible\n");
>
> - printf(" ro lock status: ");
> - if (reg & EXT_CSD_BOOT_WP_B_PWR_WP_EN)
> + reg = ext_csd[EXT_CSD_BOOT_WP_STATUS];
> + printf(" partition 0 ro lock status: ");
> + if (reg & EXT_CSD_BOOT_WP_S_AREA_0_PERM)
> + printf("locked permanently\n");
> + else if (reg & EXT_CSD_BOOT_WP_S_AREA_0_PWR)
> printf("locked until next power on\n");
> - else if (reg & EXT_CSD_BOOT_WP_B_PERM_WP_EN)
> + else
> + printf("not locked\n");
> + printf(" partition 1 ro lock status: ");
> + if (reg & EXT_CSD_BOOT_WP_S_AREA_1_PERM)
> printf("locked permanently\n");
> + else if (reg & EXT_CSD_BOOT_WP_S_AREA_1_PWR)
> + printf("locked until next power on\n");
> else
> printf("not locked\n");
> }
> @@ -260,13 +268,28 @@ int do_writeprotect_boot_set(int nargs, char **argv)
> __u8 ext_csd[512], value;
> int fd, ret;
> char *device;
> + char *end;
> + int argi = 1;
> + int permanent = 0;
> + int partition = -1;
>
> - if (nargs != 2) {
> - fprintf(stderr, "Usage: mmc writeprotect boot set </path/to/mmcblkX>\n");
> +#ifdef DANGEROUS_COMMANDS_ENABLED
> + if (!strcmp(argv[argi], "-p")){
> + permanent = 1;
> + argi++;
> + }
> +#endif
> +
> + if (nargs < 1 + argi || nargs > 2 + argi) {
> + fprintf(stderr, "Usage: mmc writeprotect boot set "
> +#ifdef DANGEROUS_COMMANDS_ENABLED
> + "[-p] "
> +#endif
> + "</path/to/mmcblkX> [0|1]\n");
> exit(1);
> }
>
> - device = argv[1];
> + device = argv[argi++];
>
> fd = open(device, O_RDWR);
> if (fd < 0) {
> @@ -274,14 +297,49 @@ int do_writeprotect_boot_set(int nargs, char **argv)
> exit(1);
> }
>
> + if (nargs == 1 + argi) {
> + partition = strtoul(argv[argi], &end, 0);
> + if (*end != '\0' || !(partition == 0 || partition == 1)) {
> + fprintf(stderr, "Invalid partition number (must be 0 or 1): %s\n",
> + argv[argi]);
> + 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_BOOT_WP] |
> - EXT_CSD_BOOT_WP_B_PWR_WP_EN;
> + value = ext_csd[EXT_CSD_BOOT_WP];
> + /*
> + * If permanent protection is already on for one partition and we're
> + * trying to enable power-reset protection for the other we need to make
> + * sure the selection bit for permanent protection still points to the
> + * former or we'll accidentally permanently protect the latter.
> + */
> + if ((value & EXT_CSD_BOOT_WP_B_PERM_WP_EN) && !permanent) {
> + if (ext_csd[EXT_CSD_BOOT_WP_STATUS] &
> + EXT_CSD_BOOT_WP_S_AREA_1_PERM) {
> + value |= EXT_CSD_BOOT_WP_B_PERM_WP_SEC_SEL;
> + if (partition != 1)
> + partition = 0;
> + } else {
> + /* PERM_WP_SEC_SEL cleared -> pointing to partition 0 */
> + if (partition != 0)
> + partition = 1;
> + }
> + }
> + if (partition != -1) {
> + value |= EXT_CSD_BOOT_WP_B_SEC_WP_SEL;
> + if (partition == 1)
> + value |= permanent ? EXT_CSD_BOOT_WP_B_PERM_WP_SEC_SEL
> + : EXT_CSD_BOOT_WP_B_PWR_WP_SEC_SEL;
> + }
> + value |= permanent ? EXT_CSD_BOOT_WP_B_PERM_WP_EN
> + : EXT_CSD_BOOT_WP_B_PWR_WP_EN;
> +
> ret = write_extcsd_value(fd, EXT_CSD_BOOT_WP, value);
> if (ret) {
> fprintf(stderr, "Could not write 0x%02x to "
> --
> 2.24.1
>
