mmc - a tool for configuring MMC storage devices

Authors

mmc-utils was written by Chris Ball <cjb@laptop.org> and <chris@printf.net>.
       It is currently maintained by Ulf Hansson <ulf.hansson@linaro.org>.

Description

mmc-utils  is a single-threaded tool that will perform a specified type of mmc action as specified by the
       user.
       The typical use of mmc-utils is  to  access  the  mmc  device  either  for  configuring  or  reading  its
       configuration registers.

Examples

RPMBexamples
              Program rpmb key using the stdin option:

                     $ echo -n AAAABBBBCCCCDDDDEEEEFFFFGGGGHHHH | mmc rpmb write-key /dev/mmcblk0rpmb -

              Read 2 blocks starting address 2 and output the received content to stdout.  Verify  the  received
              frames using the key (not mandatory):

                     $ echo -n AAAABBBBCCCCDDDDEEEEFFFFGGGGHHHH | mmc rpmb read-block /dev/mmcblk0rpmb 0x02 2 -

              Read  2  blocks  without  verification  starting  address  2  and  output  the received content to
              /tmp/block:

                     $mmc rpmb read-block /dev/mmcblk0rpmb 0x02 2 /tmp/block

              Write a string of 'a's to address 2. both the input and key uses stdin interface:

                     $ (awk 'BEGIN {while (c++<256) printf "a"}' | echo -n  AAAABBBBCCCCDDDDEEEEFFFFGGGGHHHH)  |
                     mmc rpmb write-block /dev/mmcblk0rpmb 0x02 - -

       FieldFirmwareUpdate(ffu)examples
              Do  ffu  using  max-possible  chunk size:  If the fluf size < 512k, it will be flushed in a single
              write sequence.

                     $ mmc ffu IO4e0aC2056001801M1100042AE1.fluf /dev/mmcblk0

              Same as above, this time use a 4k chunks:

                     $ mmc ffu IO4e0aC2056001801M1100042AE1.fluf /dev/mmcblk0 4096

Name

       mmc -  a tool for configuring MMC storage devices

Options

extcsdreaddevice
Read and prints the extended csd register

extcsdwriteoffsetvaluedevice
Write value at offset to the device's extcsd

writeprotectbootgetdevice
Print the boot partitions write protect status

writeprotectbootsetdevice[number]
Set the boot partition write protect status for the device.
If number is passed (0 or 1), only protect that specified eMMC boot partition, otherwise protect
both.
It will be write-protected until the next boot.

writeprotectusersettypestart-blockblocksdevice
Set the write protect configuration for the specified region of the user area for the device.
start-block specifies the first block of the protected area.
blocks specifies the size of the protected area in blocks.
NOTE! The area must start and end on Write Protect Group boundaries, Use the "writeprotect user
get" command to get the Write Protect Group size.
type is one of the following:

none Clear temporary write protection.

temp Set temporary write protection.

pwron Set write protection until the next power on.

writeprotectusergetdevice
Print the user area's write protect configuration for the device.

disable512Bemulationdevice
Set the eMMC data sector size to 4KB by disabling emulation on the device.

gpcreatedry-runlength-KiBpartitionenh-attrext-attrdevice
Create general purpose partition for the device.
NOTE! This is a one-time programmable (irreversible) change.
To set enhanced attribute to general partition being created set enh-attr to 1 else set it to 0.
To set extended attribute to general partition set enh-attr to 1,2 else set it to 0.
dry-run is one of the following:

-y PARTITION_SETTING_COMPLETED in the extcsd will get set and the partitioning
operation will take effect and be finalized.

-c more partitioning settings are still to come - partitioning operation will not take
effect.

otherwise
These changes will not take effect neither now nor after a power cycle.

enh_areasetdry-runstart-KiBlength-KiBdevice
Enable the enhanced user area for the device.
NOTE! This is a one-time programmable (irreversible) change. dry-run is as above.

write_reliabilitysetdry-runpartitiondevice
Enable write reliability per partition for the device.
NOTE! This is a one-time programmable (irreversible) change. dry-run is as above.

statusgetdevice
Print the response to STATUS_SEND (CMD13).

bootpartenableboot-partitionsend-ackndevice
Enable the boot partition for the device. Disable the boot partition for the device if is
boot-partition set to 0.
To receive acknowledgment of boot from the card set send-ackn to 1, else set it to 0.

bootbussetboot-modereset-boot-bus-conditionsboot-bus-widthdevice
Set Boot Bus Conditions.
boot-mode is one of the following: single_backward, single_hs, or dual.
reset-boot-bus-conditions is one of the following: x1 or retain.
boot-bus-width is one of the following: x1, x4, or x8.

bkops_enmodedevice
Enable the eMMC BKOPS feature on the device. The auto (AUTO_EN) setting is only supported on eMMC
5.0 or newer.
NOTE! Setting manual (MANUAL_EN) is one-time programmable (irreversible) change.
mode is one of the following:

auto Auto bkops is set

manual Manual bkops is set

hwresetenabledevice
Permanently enable the eMMC H/W Reset feature on the device.
NOTE! This is a one-time programmable (irreversible) change.

hwresetdisabledevice
Permanently disable the eMMC H/W Reset feature on the device.
NOTE! This is a one-time programmable (irreversible) change.

sanitizedevice[timeout_ms]
Send Sanitize command to the device. This will delete the unmapped memory region of the device.

rpmbwrite-keyrpmb-devicekey-file
Program authentication key which is 32 bytes length and stored in the specified file.
Also you can specify '-' instead of key file path to read the key from stdin.
NOTE! This is a one-time programmable (irreversible) change.

rpmbread-counterrpmb-device
Counter value for the rpmb-device will be read to stdout.

rpmbread-blockrpmb-deviceaddressblocks-Blocks of 256 bytes will be read from rpmb-device to output
file or stdout if '-' is specified. If key is specified - read data will be verified.

rpmbwrite-blockrpmb-deviceaddress256-byte-data-filekey-file
Block of 256 bytes will be written from data file to rpmb-device.
Also you can specify '-' instead of key file path or data file to read the data from stdin.

cacheenabledevice
Enable the eMMC cache feature on the device.
NOTE! The cache is an optional feature on devices >= eMMC4.5.

cachedisabledevice
Disable the eMMC cache feature on the device.
NOTE! The cache is an optional feature on devices >= eMMC4.5.

csdreaddevice-path
Print CSD data from device-path. The device path should specify the csd sysfs file directory.

cidreaddevice-path
Print CID data from device-path. The device path should specify the cid sysfs file directory.

scrreaddevice-path
Print SCR data from device-path. The device path should specify the scr sysfs file directory.

ffuimage-file-namedevice[chunk-bytes]
Run Field Firmware Update with image-file-name on the device.
[chunk-bytes] is optional and defaults to its max - 512k. should be in decimal bytes and sector
aligned.
if [chunk-bytes] is omitted, mmc-utils will try to run ffu using the largest possible chunks:
max(image-file, 512k).

erasetypestart-addressend-addressdevice
Send Erase CMD38 with specific argument to the device.
NOTE!: This will delete all user data in the specified region of the device.
type is one of the following: legacy, discard, secure-erase, secure-trim1, secure-trim2, or trim.

gen_cmdreaddevice [arg]
Send GEN_CMD (CMD56) to read vendor-specific format/meaning data from the device.
NOTE!: [arg] is optional and defaults to 0x1. If [arg] is specified, then [arg] must be a 32-bit
hexadecimal number, prefixed with 0x/0X. And bit0 in [arg] must be 1. Normally this command is
aimed to extract a device-health info from the device.

softresetdevice
Issues a CMD0 softreset, e.g. for testing if hardware reset for UHS works

boot_operationboot-data-filedevice
Does the alternative boot operation and writes the specified starting blocks of boot data into
the requested file. Note some limitations:

1) The boot operation must be configured first, e.g. via bootbus and/or bootpart
commands

2) The MMC must currently be running at the bus mode that is configured for the boot
operation (HS200 and HS400 not supported at all).

3) Only up to 512K bytes of boot data will be transferred.

4) The MMC will perform a soft reset, if your system cannot handle that do not use the
boot operation from mmc-utils.

--help|help|-h
Show the help

cmd--help
Show detailed help for that specific cmd or subset of commands.

Reporting Bugs

       Report bugs to the mmc mailing list <linux-mmc@vger.kernel.org>.

Rpmb Commands

       The RPMB partition on the eMMC devices  is  a  special  area  used  for  storing  cryptographically  safe
       information signed by a special secret key.
       To write and read records from this special area, authentication is needed.
       The RPMB area is *only* and *exclusively* accessed using ioctl()s from user-space.
       RPMB  commands are send using the mmc multi-ioctl, thus ensures that the atomic nature of the rpmb access
       operation.
       The rpmb device given as a parameter to the rpmb commands is not a block device but a char device.
       This was done to help the mmc driver to account for some of the rpmb peculiarities.