8-bit I/O Detection

Zynq UltraScale+ Device Technical Reference Manual (UG1085)

Document ID
UG1085
Release Date
2022-09-15
Revision
2.3 English

The BootROM also looks for the dual device, 8-bit parallel configuration. In this case, the BootROM only reads the even bits of the BootROM header because it is only accessing the first device and the header is split across both devices. The BootROM forms a 32-bit word that includes the even bits of the width detection (0x20) and image identification (0x24) parameter values. When the BootROM detects this condition, it assumes the system uses the 8-bit parallel configuration and programs the controller for the x8 operating mode. This mode is used for the rest of the boot process.

Table 11-5:      Image Attributes Offset Definition

Field Name

Bit Offset

Width

Default Value

Description

Reserved

31:16

16

0x0

 

Bhdr RSA

15:14

2

0x0

0x3: If the RSA_EN eFUSEs are not programmed, RSA authentication of the boot image is done, excluding verification of PPK hash and SPK ID.
If the RSA_EN eFUSEs are programmed, then an error is generated.
All others: RSA authentication is decided based on the RSA_EN eFUSEs

SHA2 select

13:12

2

0x0

0x3: While doing RSA authentication, SHA2 is used in place of SHA3.(1)

All others: SHA3 is used while doing RSA authentication.

CPU select

11:10

2

0x0

0x0: Cortex-R5F single (split mode).

0x1: Cortex-A53 single 32-bit.

0x2: Cortex-A53 single 64-bit.

0x3: Cortex-R5F dual (lock-step mode).

Hashing select

9:8

2

0x0

0x0, 0x1: No integrity check.

0x2: SHA2 is used as a hash function to do boot image integrity check.(1)

0x3: SHA3 is used as a hash function to do boot image integrity check.

Note:   This option should not be selected if authentication (RSA) is used. If the RSA_EN eFUSEs are programmed and this option is set, an error occurs.

PUF HD location

7:6

2

0x0

0x3: PUF HD is part of the boot header.
All others: Means PUF HD is in eFUSE.

Authenticate only

5:4

2

0x0

0x3: Boot image is only RSA signed, do not decrypt the image even if 0x28 offset is non-zero.

All others: Means if 0x28 is non-zero, then decrypt the boot image.

OP key

3:2

2

0x0

0x3: Secure header contains operational key for block 0 decryption.
All others: Means that the root device key is used for block 0 decryption.

Reserved

1:0

2

0x0

 

Notes:

1.Xilinx recommends using SHA3 only. SHA2 will be deprecated in 2019.1.