NAME

       mmc-utils - Configure MMC storage devices from userspace.

SYNOPSIS

       mmc [<command> [<args>]] [--help]

       mmc [<command>] --help

DESCRIPTION

       mmc-utils is a tool for configuring MMC storage devices from userspace.

COMMANDS AND OPTIONS

       help | --help | -h | (no arguments)
              Shows the abbreviated help menu in the terminal.

       extcsd read <device>
              Print extcsd data from <device>.

       writeprotect get <device>
              Determine the eMMC writeprotect status of <device>.

       writeprotect set <device>
              Set the eMMC writeprotect status of <device>.  This sets the eMMC to be write-protected until next
              boot.

       disable 512B emulation <device>
              Set the eMMC data sector size to 4KB by disabling emulation on <device>.

       gp create <-y|-n> <length KiB> <partition> <enh_attr> <ext_attr> <device>
              create general purpose partition for the <device>.  Dry-run only unless  -y  is  passed.   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 <ext_attr> to 1,2 else set it to 0.   NOTE!   This
              is a one-time programmable (unreversible) change.

       enh_area set <-y|-n> <start KiB> <length KiB> <device>
              Enable the enhanced user area for the <device>.  Dry-run only unless -y is passed.  NOTE!  This is
              a one-time programmable (unreversible) change.

       write_reliability set <-y|-n> <partition> <device>
              Enable write reliability per partition for the <device>.  Dry-run only unless -y is passed.  NOTE!
              This is a one-time programmable (unreversible) change.

       status get <device>
              Print the response to STATUS_SEND (CMD13).

       bootpart enable <boot_partition> <send_ack> <device>
              Enable  the  boot  partition  for  the <device>.  Disable the boot partition for the <device> with
              <boot_partition> set to 0.  To receive acknowledgment of boot from the card set <send_ack>  to  1,
              else set it to 0.

       bootbus set <boot_mode> <reset_boot_bus_conditions> <boot_bus_width> <device>
              Set    Boot    Bus    Conditions.     <boot_mode>    must    be   "single_backward|single_hs|dual"
              <reset_boot_bus_conditions> must be "x1|retain" <boot_bus_width> must be "x1|x4|x8"

       bkops enable <device>
              Enable the eMMC BKOPS feature on <device>.  NOTE!  This is a one-time programmable  (unreversible)
              change.

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

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

       sanitize <device>
              Send Sanitize command to the <device>.  This will delete the unmapped memory region of the device.

       rpmb write-key <rpmb device> <key 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 (unreversible) change.

       rpmb read-counter <rpmb device>
              Counter value for the <rpmb device> will be read to stdout.

       rpmb read-block <rpmb device> <address> <blocks count> <output file> [key file]
              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. Instead of regular path you can specify

       rpmb write-block <rpmb device> <address> <256 byte data file> <key 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.

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

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

       <cmd> --help
              Show detailed help for a command or subset of commands.

EXAMPLES

       Program authentication key from stdin:
              echo -n AAAABBBBCCCCDDDDEEEEFFFFGGGGHHHH | mmc rpmb write-key /dev/mmcblk0rpmb -

       Write a block of 256 bytes of data to an rpmb device:
              $ (awk 'BEGIN {while (c++<256) printf "a"}' | echo -n AAAABBBBCCCCDDDDEEEEFFFFGGGGHHHH) | mmc rpmb
              write-block /dev/mmcblk0rpmb 0x02 - -

       Read a block of 256 bytes of data from an rpmb device to stdout:
                $ echo -n  AAAABBBBCCCCDDDDEEEEFFFFGGGGHHHH  |  mmc  rpmb  read-block  /dev/mmcblk0rpmb  0x02  2
              /tmp/block -

       Read 2 blocks of 256 bytes from rpmb device to /tmp/block without verification:
              $ mmc rpmb read-block /dev/mmcblk0rpmb 0x02 2 /tmp/block