From 371a689f64b0da140c3bcd3f55305ffa1c3a58ef Mon Sep 17 00:00:00 2001 From: Andrei Warkentin Date: Mon, 11 Apr 2011 18:10:25 -0500 Subject: mmc: MMC boot partitions support. Allows device MMC boot partitions to be accessed. MMC partitions are treated effectively as separate block devices on the same MMC card. Signed-off-by: Andrei Warkentin Acked-by: Arnd Bergmann Signed-off-by: Chris Ball --- Documentation/mmc/00-INDEX | 2 ++ Documentation/mmc/mmc-dev-attrs.txt | 10 ++++++++++ Documentation/mmc/mmc-dev-parts.txt | 27 +++++++++++++++++++++++++++ 3 files changed, 39 insertions(+) create mode 100644 Documentation/mmc/mmc-dev-parts.txt (limited to 'Documentation') diff --git a/Documentation/mmc/00-INDEX b/Documentation/mmc/00-INDEX index fca586f..93dd7a7 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 ff2bd68..8898a95 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 0000000..2db28b8 --- /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 -- cgit v1.1 From cb87ea28ed9e75a41eb456bfcb547b4e6f10e750 Mon Sep 17 00:00:00 2001 From: John Calixto Date: Tue, 26 Apr 2011 18:56:29 -0400 Subject: mmc: core: Add mmc CMD+ACMD passthrough ioctl Allows appropriately-privileged applications to send CMD (normal) and ACMD (application-specific; preceded with CMD55) commands to cards/devices on the mmc bus. This is primarily useful for enabling the security functionality built in to every SD card. It can also be used as a generic passthrough (e.g. to enable virtual machines to control mmc bus devices directly). However, this use case has not been tested rigorously. Generic passthrough testing was only conducted for a few non-security opcodes to prove the feasibility of the passthrough. Since any opcode can be sent using this passthrough, it is very possible to render the card/device unusable. Applications that use this ioctl must have CAP_SYS_RAWIO. Security commands tested on TI PCIxx12 (SDHCI), Sigma Designs SMP8652 SoC, TI OMAP3621/OMAP3630 SoC, Samsung S5PC110 SoC, Qualcomm MSM7200A SoC. Signed-off-by: John Calixto Reviewed-by: Andrei Warkentin Reviewed-by: Arnd Bergmann Signed-off-by: Chris Ball --- Documentation/ioctl/ioctl-number.txt | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation') diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index a0a5d82..2a34d82 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: 0xB1 00-1F PPPoX +0xB3 00 linux/mmc/ioctl.h 0xC0 00-0F linux/usb/iowarrior.h 0xCB 00-1F CBM serial IEC bus in development: -- cgit v1.1