Boot Header

Versal Adaptive SoC Technical Reference Manual (AM011)

Document ID

AM011

Release Date

2023-10-05

Revision

1.6 English

The boot header in the programmable device image (PDI) is read by the PMC ROM code unit (RCU) to determine key information such as the platform loader and manager (PLM) location and size, the boot mode bus width, and security encryption key details. The boot header format information is listed in the following table. For additional information on the PDI format, boot header, boot header attributes, meta header, or partition headers see the Bootgen User Guide (UG1283).

Table 1. Boot Header Format
Offset (Hex)	Size (Bytes)	Description	Details
`0x00`	16	SelectMAP bus width	Used to determine if the SelectMAP bus width is x8, x16, or x32. See SelectMAP Bus Width Detect Pattern and Bit Order for the unique entries.
`0x10`	4	QSPI bus width	QSPI bus width description. This is required to identify the QSPI flash in single/dual stacked or dual parallel mode. `0xAA995566` in the little endian format.
`0x14`	4	Image identification	Boot image identification string. Contains 4 bytes X, N, L, X in byte order, which is `0x584c4e58` in the little endian format.
`0x18`	4	Encryption key source	This field is used to identify the AES key source: `0x00000000` - Unencrypted `0xA5C3C5A3` - eFUSE red key `0xA5C3C5A5` - eFUSE black key `0x3A5C3C5A` - BBRAM red key `0x3A5C3C59` - BBRAM black key `0xA35C7C53` - Boot header black key
`0x1C`	4	PLM source offset	PLM source start address in PDI.
`0x20`	4	PMC data load address	PMC CDO address to load. The PMC CDO data load address must be `0xF200_0000` for proper PLM operation.
`0x24`	4	PMC data length	PMC CDO length.
`0x28`	4	Total PMC data length	PMC CDO length including authentication and encryption overhead.
`0x2C`	4	PLM length	PLM original image size.
`0x30`	4	Total PLM length	PLM image size including the authentication and encryption overhead.
`0x34`	4	Boot header attributes	Boot header attributes.
`0x38`	32	Black key	256-bit key, only valid when encryption status is set to black key in boot header.
`0x58`	12	Black IV	Initialization vector used when decrypting the black key.
`0x64`	12	Secure header IV	Secure header initialization vector.
`0x70`	4	PUF shutter value	Length of time the PUF samples before it closes the shutter. Note: This shutter value must match the shutter value that was used during PUF registration.
`0x74`	12	Secure header IV for PMC data	The IV used to decrypt secure header of PMC data.
`0x80`	68	reserved	Populate with zeroes.
`0xC4`	4	Meta header offset	Offset to the start of the meta header.
`0xC8`-`0x124`	96	reserved
`0x128`	2048	Register initialization	Stores register write pairs for system register initialization. See TRM Boot Header Register Initialization Feature section and Bootgen User Guide (UG1283) for more detail.
`0x928`	1544	PUF helper data	PUF helper data.
`0xF30`	4	Checksum	Header checksum. The boot header checksum covers offset range `0x10` to `0xF30`.
`0xF34`	76	SHA3 padding	SHA3 standard padding.