fwupd/plugins/emmc/README.md
Richard Hughes 078beafb2d Add a new internal flag to opt-in to GUID matching
It is far too easy to forget to set FWUPD_DEVICE_FLAG_NO_GUID_MATCHING for new
plugins, and without it it all works really well *until* a user has two devices
of the same type installed at the same time and then one 'disappears' for hard
to explain reasons. Typically we only need it for replug anyway!

Explicitly opt-in to this rarely-required behaviour, with the default to just
use the physical and logical IDs. Also document the update behavior for each
plugin to explain why the flag is being used.

This allows you to have two identical Unifying plugged in without one of them
being hidden from the user, at the same time allowing a HIDRAW<->USB transition
when going to and from bootloader and runtime modes.

This removes the workaround added in 99eb3f06b6.

Fixes https://github.com/fwupd/fwupd/issues/2915
2021-02-25 15:47:25 +00:00

811 B

eMMC Support

Introduction

This plugin reads the sysfs attributes corresponding to eMMC devices. It uses the kernel MMC API for flashing devices.

Protocol

eMMC devices support the org.jedec.mmc protocol.

GUID Generation

These devices use the following instance values:

  • EMMC\%NAME%
  • EMMC\%MANFID%&%OEMID%
  • EMMC\%MANFID%&%OEMID%&%NAME%

Update Behavior

The firmware is deployed when the device is in normal runtime mode, but it is only activated when the device is rebooted.

Vendor ID Security

The vendor ID is set from the EMMC vendor, for example set to EMMC:{$manfid}

External interface access

This plugin requires ioctl MMC_IOC_CMD and MMC_IOC_MULTI_CMD access.