Hi Nxp,
i am working on a ramcode application to read hse status by jlink on PC. for a empty chip with hse installed , i found if ramcode with basic boot sign, if could run but fail to call hse service, why cause that happen?
it says that ivt only check 0x400000, 0x500000, 0x10000000 , these three addresses and boot, my ramcode is located on 0x20400000, ivt header, and 0x20401fC0 for app-header.
load the ramcode and set PC register to reset handler to run, it's not use ivt header /appbl header.
if a changed ivt-header to other value , hse could run. but for ramcode should run for all board settings( hse set ivt auth, lifecycle). is it necessary to sign a ramcode or it needs a ivt-header?
thanks.
Hi @victory
If there's no valid IVT, the device goes to recovery mode. See "2.6.1.3 Recovery Mode" in HSE Firmware Reference Manual for details. If you don't enable secure mode, it goes to JTAG based recovery mode. Here it depends on life cycle. If it is still in CUST_DEL, the device will wait for debugger connection and you can use your RAM code and HSE services. If life cycle is advanced - see Figure 11 for details. I guess that this could be the problem.
Regards,
Lukas