AM2634: which memory address to put the certification information and encrypted image

Terry Deng

Expert 3005 points

Part Number: AM2634

Tool/software:

Hi Expert

Customer ask which memory address to put the certification information and encrypted image? May I get the advice?

3 months ago

0 Nilabh Anand 3 months ago

TI__Mastermind 48820 points

Hi Terry,

The SBl is always located at 0x0 offset in flash, so the certificate info needs to present at same location

For Application also the offset is programmed via SBL, so certificate is present at the top.

0 Terry Deng 3 months ago in reply to Nilabh Anand

TI__Expert 3005 points

Hi Nilabh

Thank you, could you help advice more detail offset for certification internal components?

There are Public key, SW rev, Image Integrity..... and so on in the certification info, customer ask what size for each components, and what is the offset for encrypted image after certification?

0 Nilabh Anand 3 months ago in reply to Terry Deng

TI__Mastermind 48820 points

BTW x509 certificate is a RFC standard(not tI specific)- datatracker.ietf.org/.../rfc5280

Please ask customer to refer to this:

https://software-dl.ti.com/mcu-plus-sdk/esd/AM263PX/latest/exports/docs/api_guide_am263px/BOOTFLOW_GUIDE.html

https://software-dl.ti.com/mcu-plus-sdk/esd/AM263PX/latest/exports/docs/api_guide_am263px/SECURE_BOOT.html#autotoc_md319

0 Terry Deng 3 months ago in reply to Nilabh Anand

TI__Expert 3005 points

Hi Nilabh

I have read the document but cannot understand clearly the memory size for each component in certification. Should I take below format as reference? How to read the memory size from below?

0 Nilabh Anand 3 months ago in reply to Terry Deng

TI__Mastermind 48820 points

Hi Terry,

I am not sure what the customer is trying here:

Please note that the certificate is not TI specific it is a standard format used across the industry, please ask the customer to study it properly, yes, you can use the above as a reference.

1. Version: INTEGER (v1(0), v2(1), v3(2))

2. SerialNumber: INTEGER

3. Validity: SEQUENCE of two Time values (notBefore, notAfter)

4. UniqueIdentifier: BIT STRING

5. SubjectPublicKeyInfo: SEQUENCE containing:

- algorithm: AlgorithmIdentifier
- subjectPublicKey: BIT STRING

6. Extensions: SEQUENCE SIZE (1..MAX) OF Extension Where Extension is a SEQUENCE containing:

- extnID: OBJECT IDENTIFIER
- critical: BOOLEAN DEFAULT FALSE
- extnValue: OCTET STRING

Important notes about sizes:

- Many fields use variable-length encodings (BIT STRING, OCTET STRING)
- INTEGER fields like SerialNumber have no specified maximum size
- Time values can be either UTCTime or GeneralizedTime format
- Extensions can have 1 or more entries (specified by SIZE (1..MAX))
- The actual size of fields like public keys depends on the specific algorithms used (RSA key sizes, ECC curves, etc.)

Arm-based microcontrollers

Arm-based microcontrollers forum

AM2634: which memory address to put the certification information and encrypted image