Keep same header structure in SRK Table and Record

[csoapy]

I'm writing code to parse container file. And found that there are 3 similar struct headers used to indicate data block's TAG, SIZE and VERSION:

A: { VERSION, LENGTH_L, LENGHT_H, TAG}

        Used in Container, SignatureBlock, Signature, Certificate, Block(DEK)'s header.

B: {TAG,  LENGTH_L/H, LENGHT_H/L, VERSION}

        Used in SRK Table's header.

C: {Tag, LENGTH_L/H, LENGHT_H/L}

        Used in SRK Record's header

P.S. I use `L/H` because there are labled as `Variable` in a fixed length of 2 bytes in i.MX8 RM Rev.0

This two make me confused:

1. Why not use same structures?
2. Why not place TAG to the first byte of a structure?

[csoapy]

Another weird order in Signature Block:

Offset:    {Certi,           SRK Table,  Sign, Blob}

Content: {SRK Table, Sign,            Certi, Blob}

[igorpadykov]

processor ROM structures and definitions are hardcoded at chip design level,

they can not be changed later.

Best regards
igor

[csoapy]

processor ROM structures and definitions are hardcoded at chip design level,

they can not be changed later.

Since it's hardcoded, then hardcode them again.

I don't think they can not be changed later.

There're i.MX8 B0 and C0 release. So why can't fix them in D0?

It's about how much works need to be done.

It's not about CAN or CAN NOT.

BAD is BAD. and need to be fixed.

[igorpadykov]

Hi csoapy

one can refer to tutorial for creating i.MX8 image

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX8-Boot-process-and-creating-a-bootab...

AHAB documentation

https://source.codeaurora.org/external/imx/uboot-imx/tree/doc/imx/ahab?h=imx_v2020.04_5.4.24_2.1.0

Secure Boot on i.MX 8 and i.MX 8X Families using AHAB

Best regards
igor

[csoapy]

@igorpadykov  Can you delete your reply? It's not an answer to the question.

[igorpadykov]

 answer to the questions:

1. Why not use same structures?
2. Why not place TAG to the first byte of a structure?
3.  

A: it is defined in i.MX8 ROM.

Best regards
igor

[csoapy]

@igorpadykov  I mean, it's a bad definition, a bad design in another word.

[igorpadykov]

>I mean, it's a bad definition, a bad design in another word.

sorry processor ROM structures and definitions are hardcoded at chip design level,

they can not be changed later.

Best regards
igor