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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/mmc/mmc-dev-parts.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/mmc/mmc-dev-parts.txt')
-rw-r--r-- | kernel/Documentation/mmc/mmc-dev-parts.txt | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/kernel/Documentation/mmc/mmc-dev-parts.txt b/kernel/Documentation/mmc/mmc-dev-parts.txt new file mode 100644 index 000000000..f08d078d4 --- /dev/null +++ b/kernel/Documentation/mmc/mmc-dev-parts.txt @@ -0,0 +1,40 @@ +SD and MMC Device Partitions +============================ + +Device partitions are additional logical block devices present on the +SD/MMC device. + +As of this writing, MMC boot partitions as supported and exposed as +/dev/mmcblkXboot0 and /dev/mmcblkXboot1, where X is the index of the +parent /dev/mmcblkX. + +MMC Boot Partitions +=================== + +Read and write access is provided to the two MMC boot partitions. Due to +the sensitive nature of the boot partition contents, which often store +a bootloader or bootloader configuration tables crucial to booting the +platform, write access is disabled by default to reduce the chance of +accidental bricking. + +To enable write access to /dev/mmcblkXbootY, disable the forced read-only +access with: + +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. |