diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ioctl/ioctl-number.txt | 1 | ||||
| -rw-r--r-- | Documentation/mmc/00-INDEX | 2 | ||||
| -rw-r--r-- | Documentation/mmc/mmc-dev-attrs.txt | 10 | ||||
| -rw-r--r-- | Documentation/mmc/mmc-dev-parts.txt | 27 |
4 files changed, 40 insertions, 0 deletions
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index 2d1ad12e2b3..3a46e360496 100644 --- a/Documentation/ioctl/ioctl-number.txt +++ b/Documentation/ioctl/ioctl-number.txt @@ -304,6 +304,7 @@ Code Seq#(hex) Include File Comments 0xB0 all RATIO devices in development: <mailto:vgo@ratio.de> 0xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca> +0xB3 00 linux/mmc/ioctl.h 0xC0 00-0F linux/usb/iowarrior.h 0xCB 00-1F CBM serial IEC bus in development: <mailto:michael.klein@puffin.lb.shuttle.de> diff --git a/Documentation/mmc/00-INDEX b/Documentation/mmc/00-INDEX index fca586f5b85..93dd7a71407 100644 --- a/Documentation/mmc/00-INDEX +++ b/Documentation/mmc/00-INDEX @@ -2,3 +2,5 @@ - this file mmc-dev-attrs.txt - info on SD and MMC device attributes +mmc-dev-parts.txt + - info on SD and MMC device partitions diff --git a/Documentation/mmc/mmc-dev-attrs.txt b/Documentation/mmc/mmc-dev-attrs.txt index ff2bd685bce..8898a95b41e 100644 --- a/Documentation/mmc/mmc-dev-attrs.txt +++ b/Documentation/mmc/mmc-dev-attrs.txt @@ -1,3 +1,13 @@ +SD and MMC Block Device Attributes +================================== + +These attributes are defined for the block devices associated with the +SD or MMC device. + +The following attributes are read/write. + + force_ro Enforce read-only access even if write protect switch is off. + SD and MMC Device Attributes ============================ diff --git a/Documentation/mmc/mmc-dev-parts.txt b/Documentation/mmc/mmc-dev-parts.txt new file mode 100644 index 00000000000..2db28b8e662 --- /dev/null +++ b/Documentation/mmc/mmc-dev-parts.txt @@ -0,0 +1,27 @@ +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 |