diff options
author | Glenn Elliott <gelliott@cs.unc.edu> | 2012-03-04 19:47:13 -0500 |
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committer | Glenn Elliott <gelliott@cs.unc.edu> | 2012-03-04 19:47:13 -0500 |
commit | c71c03bda1e86c9d5198c5d83f712e695c4f2a1e (patch) | |
tree | ecb166cb3e2b7e2adb3b5e292245fefd23381ac8 /Documentation/mmc | |
parent | ea53c912f8a86a8567697115b6a0d8152beee5c8 (diff) | |
parent | 6a00f206debf8a5c8899055726ad127dbeeed098 (diff) |
Merge branch 'mpi-master' into wip-k-fmlpwip-k-fmlp
Conflicts:
litmus/sched_cedf.c
Diffstat (limited to 'Documentation/mmc')
-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 |
3 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/mmc/00-INDEX b/Documentation/mmc/00-INDEX index fca586f5b853..93dd7a714075 100644 --- a/Documentation/mmc/00-INDEX +++ b/Documentation/mmc/00-INDEX | |||
@@ -2,3 +2,5 @@ | |||
2 | - this file | 2 | - this file |
3 | mmc-dev-attrs.txt | 3 | mmc-dev-attrs.txt |
4 | - info on SD and MMC device attributes | 4 | - info on SD and MMC device attributes |
5 | mmc-dev-parts.txt | ||
6 | - info on SD and MMC device partitions | ||
diff --git a/Documentation/mmc/mmc-dev-attrs.txt b/Documentation/mmc/mmc-dev-attrs.txt index ff2bd685bced..8898a95b41e5 100644 --- a/Documentation/mmc/mmc-dev-attrs.txt +++ b/Documentation/mmc/mmc-dev-attrs.txt | |||
@@ -1,3 +1,13 @@ | |||
1 | SD and MMC Block Device Attributes | ||
2 | ================================== | ||
3 | |||
4 | These attributes are defined for the block devices associated with the | ||
5 | SD or MMC device. | ||
6 | |||
7 | The following attributes are read/write. | ||
8 | |||
9 | force_ro Enforce read-only access even if write protect switch is off. | ||
10 | |||
1 | SD and MMC Device Attributes | 11 | SD and MMC Device Attributes |
2 | ============================ | 12 | ============================ |
3 | 13 | ||
diff --git a/Documentation/mmc/mmc-dev-parts.txt b/Documentation/mmc/mmc-dev-parts.txt new file mode 100644 index 000000000000..2db28b8e662f --- /dev/null +++ b/Documentation/mmc/mmc-dev-parts.txt | |||
@@ -0,0 +1,27 @@ | |||
1 | SD and MMC Device Partitions | ||
2 | ============================ | ||
3 | |||
4 | Device partitions are additional logical block devices present on the | ||
5 | SD/MMC device. | ||
6 | |||
7 | As of this writing, MMC boot partitions as supported and exposed as | ||
8 | /dev/mmcblkXboot0 and /dev/mmcblkXboot1, where X is the index of the | ||
9 | parent /dev/mmcblkX. | ||
10 | |||
11 | MMC Boot Partitions | ||
12 | =================== | ||
13 | |||
14 | Read and write access is provided to the two MMC boot partitions. Due to | ||
15 | the sensitive nature of the boot partition contents, which often store | ||
16 | a bootloader or bootloader configuration tables crucial to booting the | ||
17 | platform, write access is disabled by default to reduce the chance of | ||
18 | accidental bricking. | ||
19 | |||
20 | To enable write access to /dev/mmcblkXbootY, disable the forced read-only | ||
21 | access with: | ||
22 | |||
23 | echo 0 > /sys/block/mmcblkXbootY/force_ro | ||
24 | |||
25 | To re-enable read-only access: | ||
26 | |||
27 | echo 1 > /sys/block/mmcblkXbootY/force_ro | ||