Tool/software:
Hi TI experts,
We would like to leverage the Extended OTP to store the MAC address. We found the Linux driver (ti_sci) that handles TISCI messages for other purposes and we extended this driver to add OTP messages (read/write/lock/status). We created another kernel driver that leverages the new OTP messages and exposes an interface to user space.
We also updated u-boot sec-cfg.yaml (otp_config) to set the write_host_id and host_id to 12 to match the Linux host_id. Also, host_perms were set to 2.
otp_config:
subhdr:
magic: 0x4081
size: 69
write_host_id : 12
otp_entry:
- #1
host_id: 12
host_perms: 2
- #2
host_id: 12
host_perms: 2
- #3
host_id: 12
host_perms: 2
- #4
host_id: 12
host_perms: 2
....The issue that we are running into is that we get a NAK or no response for the OTP messages. The messages seem to be transferred ok over the mailbox and the callback happened, but the response flags were all zeros ((flags = 0x00000000).
1. Any potential issue with approach? We don't plan on storing anything sensitive to the extended OTP.
2. What could be the issue that result in a NAK? How could we confirm/check that the board security configuration is correct on the device?
3. What would be your recommendation moving forward?
Anh-Tuan
