From 5844e36869cfd9dfc5e2c348c137976771b685aa Mon Sep 17 00:00:00 2001 From: Nicolas Schichan Date: Tue, 15 Nov 2022 14:55:13 +0100 Subject: [PATCH 2/7] mmc-utils: allow to permanently disable permanent write protection on whole device partitions. --- mmc.c | 7 ++++++- mmc_cmds.c | 37 +++++++++++++++++++++++++++++++++++++ mmc_cmds.h | 1 + 3 files changed, 44 insertions(+), 1 deletion(-) diff --git a/mmc.c b/mmc.c index 52dfe74..375ed48 100644 --- a/mmc.c +++ b/mmc.c @@ -63,7 +63,12 @@ static struct Command commands[] = { }, { do_writeprotect_boot_perm_dis, -1, "writeprotect boot perm dis", "\n" - "permanently disable permanent write protection (sic)", + "permanently disable permanent write protection on boot partitions", + NULL, + }, + { do_writeprotect_device_perm_dis, -1, + "writeprotect device perm dis", "\n" + "permanently disable permanent write protection on all partitions", NULL, }, { do_writeprotect_boot_get, -1, diff --git a/mmc_cmds.c b/mmc_cmds.c index 303c9b8..34fa810 100644 --- a/mmc_cmds.c +++ b/mmc_cmds.c @@ -391,6 +391,43 @@ int do_writeprotect_boot_perm_dis(int nargs, char **argv) return ret; } +int do_writeprotect_device_perm_dis(int nargs, char **argv) +{ + __u8 ext_csd[512], value; + const char *device = argv[1]; + int fd, ret = 0; + + if (nargs != 2) { + fprintf(stderr, "Usage: mmc writeprotect device perm dis " + "\n"); + exit(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); + } + + value = ext_csd[EXT_CSD_USER_WP]; + value |= USER_WP_CD_PERM_WP_DIS; + ret = write_extcsd_value(fd, EXT_CSD_USER_WP, value, 0); + if (ret) { + fprintf(stderr, "Could not write 0x%02x to " + "EXT_CSD[%d] in %s\n", + value, EXT_CSD_USER_WP, device); + exit(1); + } + + return ret; +} + static char *prot_desc[] = { "No", "Temporary", diff --git a/mmc_cmds.h b/mmc_cmds.h index f73abbb..9f6e611 100644 --- a/mmc_cmds.h +++ b/mmc_cmds.h @@ -23,6 +23,7 @@ int do_write_extcsd(int nargs, char **argv); int do_writeprotect_boot_get(int nargs, char **argv); int do_writeprotect_boot_set(int nargs, char **argv); int do_writeprotect_boot_perm_dis(int nargs, char **argv); +int do_writeprotect_device_perm_dis(int nargs, char **argv); int do_writeprotect_user_get(int nargs, char **argv); int do_writeprotect_user_set(int nargs, char **argv); int do_disable_512B_emulation(int nargs, char **argv); -- 2.34.1