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+.. SPDX-License-Identifier: GPL-2.0-only
+
+==================================
+PLDM Firmware file format overview
+==================================
+
+A PLDM firmware package is a binary file which contains a header that
+describes the contents of the firmware package. This includes an initial
+package header, one or more firmware records, and one or more components
+describing the actual flash contents to program.
+
+This diagram provides an overview of the file format::
+
+ overall file layout
+ +----------------------+
+ | |
+ | Package Header |
+ | |
+ +----------------------+
+ | |
+ | Device Records |
+ | |
+ +----------------------+
+ | |
+ | Component Info |
+ | |
+ +----------------------+
+ | |
+ | Package Header CRC |
+ | |
+ +----------------------+
+ | |
+ | Component Image 1 |
+ | |
+ +----------------------+
+ | |
+ | Component Image 2 |
+ | |
+ +----------------------+
+ | |
+ | ... |
+ | |
+ +----------------------+
+ | |
+ | Component Image N |
+ | |
+ +----------------------+
+
+Package Header
+==============
+
+The package header begins with the UUID of the PLDM file format, and
+contains information about the version of the format that the file uses. It
+also includes the total header size, a release date, the size of the
+component bitmap, and an overall package version.
+
+The following diagram provides an overview of the package header::
+
+ header layout
+ +-------------------------+
+ | PLDM UUID |
+ +-------------------------+
+ | Format Revision |
+ +-------------------------+
+ | Header Size |
+ +-------------------------+
+ | Release Date |
+ +-------------------------+
+ | Component Bitmap Length |
+ +-------------------------+
+ | Package Version Info |
+ +-------------------------+
+
+Device Records
+==============
+
+The device firmware records area starts with a count indicating the total
+number of records in the file, followed by each record. A single device
+record describes what device matches this record. All valid PLDM firmware
+files must contain at least one record, but optionally may contain more than
+one record if they support multiple devices.
+
+Each record will identify the device it supports via TLVs that describe the
+device, such as the PCI device and vendor information. It will also indicate
+which set of components that are used by this device. It is possible that
+only subset of provided components will be used by a given record. A record
+may also optionally contain device-specific package data that will be used
+by the device firmware during the update process.
+
+The following diagram provides an overview of the device record area::
+
+ area layout
+ +---------------+
+ | |
+ | Record Count |
+ | |
+ +---------------+
+ | |
+ | Record 1 |
+ | |
+ +---------------+
+ | |
+ | Record 2 |
+ | |
+ +---------------+
+ | |
+ | ... |
+ | |
+ +---------------+
+ | |
+ | Record N |
+ | |
+ +---------------+
+
+ record layout
+ +-----------------------+
+ | Record Length |
+ +-----------------------+
+ | Descriptor Count |
+ +-----------------------+
+ | Option Flags |
+ +-----------------------+
+ | Version Settings |
+ +-----------------------+
+ | Package Data Length |
+ +-----------------------+
+ | Applicable Components |
+ +-----------------------+
+ | Version String |
+ +-----------------------+
+ | Descriptor TLVs |
+ +-----------------------+
+ | Package Data |
+ +-----------------------+
+
+Component Info
+==============
+
+The component information area begins with a count of the number of
+components. Following this count is a description for each component. The
+component information points to the location in the file where the component
+data is stored, and includes version data used to identify the version of
+the component.
+
+The following diagram provides an overview of the component area::
+
+ area layout
+ +-----------------+
+ | |
+ | Component Count |
+ | |
+ +-----------------+
+ | |
+ | Component 1 |
+ | |
+ +-----------------+
+ | |
+ | Component 2 |
+ | |
+ +-----------------+
+ | |
+ | ... |
+ | |
+ +-----------------+
+ | |
+ | Component N |
+ | |
+ +-----------------+
+
+ component layout
+ +------------------------+
+ | Classification |
+ +------------------------+
+ | Component Identifier |
+ +------------------------+
+ | Comparison Stamp |
+ +------------------------+
+ | Component Options |
+ +------------------------+
+ | Activation Method |
+ +------------------------+
+ | Location Offset |
+ +------------------------+
+ | Component Size |
+ +------------------------+
+ | Component Version Info |
+ +------------------------+
+ | Package Data |
+ +------------------------+
+
+
+Package Header CRC
+==================
+
+Following the component information is a short 4-byte CRC calculated over
+the contents of all of the header information.
+
+Component Images
+================
+
+The component images follow the package header information in the PLDM
+firmware file. Each of these is simply a binary chunk with its start and
+size defined by the matching component structure in the component info area.