Component: Information about the number & density of all components, read, write and erase frequencies as well as invalid instructions.Map: Pointers to all the descriptor sections as well as the size of each.Header: Consists of a 0x16 sized Reset Vector and a 0x4 sized Signature tag 0x5AA5F00F.The fixed size of the Flash Descriptor is 4 KB (0x1000) and, depending on platform generation, roughly consists of these sections: It contains information such as space allocated for each region of the flash image, read-write permissions for each region, reserved space for vendor-specific data, chipset configuration parameters and more. The Intel Flash Descriptor (FD) is a data structure that is programmed on the SPI flash chip on all Intel based platforms. This guide will focus on its first region, the Flash Descriptor.

Although the SPI image can be commonly referred to as 'BIOS' or 'UEFI', it is very important to note that it is not technically the same, as the BIOS/UEFI is only one of its regions. The SPI firmware image of Intel based systems consists of various regions such as Flash Descriptor, (Management/Trusted Execution) Engine, Gigabit Ethernet, BIOS/UEFI and so on. In this guide, the term 'system' means an individual user machine whereas 'model' refers to all those 'systems' released by the OEM/ODM.Įvery system stores its firmware at one or more SPI chips. This guide is relevant to those who need to understand what the Intel Flash Descriptor is, how its SPI Region Read/Write Access Permissions work, how to check its Locked/Unlocked status and what methods are available to unlock it for system firmware repair and/or updating.

Intel fpt flash programming tool