From add710eaa88606de8ba98a014d37178579e6dbaf Mon Sep 17 00:00:00 2001 From: Johan Rudholm Date: Fri, 2 Dec 2011 08:51:06 +0100 Subject: mmc: boot partition ro lock support Enable boot partitions to be read-only locked until next power on via a sysfs entry. There will be one sysfs entry for each boot partition: /sys/block/mmcblkXbootY/ro_lock_until_next_power_on Each boot partition is locked by writing 1 to its file. Signed-off-by: Johan Rudholm Signed-off-by: John Beckett Signed-off-by: Chris Ball --- Documentation/mmc/mmc-dev-parts.txt | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'Documentation/mmc') diff --git a/Documentation/mmc/mmc-dev-parts.txt b/Documentation/mmc/mmc-dev-parts.txt index 2db28b8e662f..f08d078d43cf 100644 --- a/Documentation/mmc/mmc-dev-parts.txt +++ b/Documentation/mmc/mmc-dev-parts.txt @@ -25,3 +25,16 @@ echo 0 > /sys/block/mmcblkXbootY/force_ro To re-enable read-only access: echo 1 > /sys/block/mmcblkXbootY/force_ro + +The boot partitions can also be locked read only until the next power on, +with: + +echo 1 > /sys/block/mmcblkXbootY/ro_lock_until_next_power_on + +This is a feature of the card and not of the kernel. If the card does +not support boot partition locking, the file will not exist. If the +feature has been disabled on the card, the file will be read-only. + +The boot partitions can also be locked permanently, but this feature is +not accessible through sysfs in order to avoid accidental or malicious +bricking. -- cgit v1.2.3