How to enable/disable the secure boot authentication feature on MSM8660 by using the JTAG

Notes: This solution does not apply all version MSM8660


This solution does not apply to the RPM JTAG disable cases

This solution only uses for debug purpose.




For some reasons, if you need to to run unsigned software on a secure boot enabled (the AUTH_EN bit in SECURE_BOOT1 register is blown) MSM8660 chip, the following instruction is able to disable the secure boot authentication by using RPM-JTAG.




1. Launch the Daisy Chain RPM-JTAG shortcut (i.e modem_proc\tools\t32\DC7_ARM7_RPM).

2. Execute the cmm script which contain the following command:

system.option resbreak on
system.up
g 0x7ce8 /o /cmd "r.s r0 0x0" ;0x0 for disabling the secure boot authentication
wait 1ms
g

Of course, you can simply modify the cmm script (listed below) to enable the secure boot authentication without blowing SECURE_BOOT1 register on MSM8660 chip by using RPM-JTAG or short the GPIO_76 pin.

system.option resbreak on
system.up
g 0x7ce8 /o /cmd "r.s r0 0x1" ;0x1 for enabling the secure boot authentication
wait 1ms
g