3 HS Device Return

HS device returns are more complicated as the JTAG interface is closed and TI cannot have access to and do more testing for this. TI needs customer help to generate wait in reset (WIR) Cert, SBL/SPL Cert, and DMSC FW. Those binaries will help TI unlock the JTAG and log in to the HLOS continue to follow-up process. The return test process of Jacinto7 series device is shown in Figure 3-1. HS credentials handshake is mandatory to enable HS device test.

Customer signed WIR certificate required to enable both: ATE Testing; Bench Testing. Customers can use allow_wildcard_unlock = 0x5A in the Boardcfg file in the development stage to skip the UID verification, but in the mass production stage, this parameter must be set to 0 to enable UID verification. CRP is mainly aimed at mass production projects. The corresponding firmware provided by TI (allow_wildcard_unlock = 0x0) is to enable UID verification. After the customer signs the firmware, the UID needs to be verified before the firmware enters the system. Only after passing the verification can it succeed Start the system. Therefore, this firmware can only be used to unlock the device that you have provided the UID to further protect the customer's information security. Device UID is unique per device. Certificates enables debug on only one device. This involves exchange of information between Customer and TI for each returned device. Secondary App debug requires additional signed images. Customer must sign TI bootloader and firmware images with device root key (Private Key).

After the New QTS Job be created, the CRP cannot start until TI:

• Receives device (customer removes from board and ships)
• Re-balls device
• Extracts Device UID and creates certificate inputs and sends to customer contact
• Receives customer signed certificates