#### Plugin: MTD

## Introduction

The Memory Technology Device (MTD) interface is a way of abstracting flash devices as if they were normal block devices.

See http://www.linux-mtd.infradead.org/doc/general.html for more details.

This plugin supports the following protocol ID:

- `org.infradead.mtd`

## GUID Generation

These devices use custom DeviceInstanceId values built from the device `NAME` and DMI data, e.g.

- `MTD\NAME_Factory`
- `MTD\VENDOR_foo&NAME_baz`
- `MTD\VENDOR_foo&PRODUCT_bar&NAME_baz`

If the `FirmwareGType` quirk is set for the device then the firmware is read back from the device at daemon startup and parsed for the version number. In the event the firmware has multiple child images then the device GUIDs are used as firmware IDs.

## Update Behavior

The MTD device is erased in chunks, written and then read back to verify.

Although fwupd can read and write a raw image to the MTD partition there is no automatic way to get the existing version number. By providing the `GType` fwupd can read the MTD partition and discover additional metadata about the image. For instance, adding a quirk like:

    [MTD\VENDOR_PINE64&PRODUCT_PinePhone-Pro&NAME_spi1.0]
    FirmwareGType = FuUswidFirmware

… and then append or insert the image into the MTD image with prepared SBOM metadata:

    pip install uswid
    uswid --load uswid.ini --save metadata.uswid

This would allow fwupd to read the MTD image data, look for a uSWID data section and then parse the metadata from that. Any of the firmware formats supported by `fwupdtool get-firmware-gtypes` that can provide a version can be used.

## Quirk Use

This plugin uses the following plugin-specific quirks:

### MtdMetadataOffset

The offset to start searching within the MTD partition when using `FirmwareGType`. This is provided to avoid dumping a huge amount of MTD data to access a tiny chunk of data that will not be before a known offset.

Since: 1.9.1

### MtdMetadataSize

The size of data to read from the MTD partition when using `FirmwareGType`. This is provided to avoid dumping a huge amount of MTD data to access a tiny chunk of data.

Since: 1.9.1

## Vendor ID Security

The vendor ID is set from the system vendor, for example `DMI:LENOVO`

## External Interface Access

This plugin requires read/write access to `/dev/mtd`.

## Version Considerations

This plugin has been available since fwupd version `1.7.2`.