fwupd/plugins/flashrom

Flashrom

Introduction

This plugin uses libflashrom to update the system firmware. It can be used to update BIOS or ME regions of the flash. Device for ME region is created only if "Intel SPI" plugin indicates that such a region exists, which makes "Intel SPI" a dependency of this plugin for doing ME updates.

Firmware Format

The daemon will decompress the cabinet archive and extract a firmware blob in an unspecified binary file format, which is typically the raw input for an EEPROM programmer.

This plugin supports the following protocol ID:

• org.flashrom

Coreboot Version String

The coreboot version string can have an optional prefix (see below). After the optional prefix the major, minor string follows and finally the build string, containing the exact commit and repository state, follows.

For example 4.10-989-gc8a4e4b9c5-dirty

Exception on Lenovo devices

The thinkpad_acpi kernel module requires a specific pattern in the DMI version string. To satisfy those requirements coreboot adds the CBETxxxx prefix to the DMI version string on all Lenovo devices.

For example CBET4000 4.10-989-gc8a4e4b9c5-dirty

The coreboot DMI version string always starts with CBET.

GUID Generation

Internal device uses hardware ID values which are derived from SMBIOS.

• HardwareID-3
• HardwareID-4
• HardwareID-5
• HardwareID-6
• HardwareID-10

They should match the values provided by fwupdtool hwids or the ComputerHardwareIds.exe Windows utility.

One more GUID has the following form:

• FLASHROM\VENDOR_{manufacturer}&PRODUCT_{product}&REGION_{ifd_region_name}

Its purpose is to target specific regions of the flash as defined by IFD (Intel SPI Flash Descriptor), examples:

• FLASHROM\VENDOR_Notebook&PRODUCT_NS50MU&REGION_BIOS
• FLASHROM\VENDOR_Notebook&PRODUCT_NS50MU&REGION_ME

Update Behavior

The firmware is deployed to the SPI chip when the machine is in normal runtime mode, but it is only used when the device is rebooted.

Vendor ID Security

The vendor ID is set from the BIOS vendor, for example DMI:Google

External Interface Access

This plugin requires access to all interfaces that libflashrom has been compiled for. This typically is /sys/bus/spi but there may be other interfaces as well.