Hello,
We have designed a custom board based on the STM32MP157F-DK2 platform.
The design uses the STM32MP157FAC MPU and includes the following peripherals:
MicroSD (SDMMC)
STPMIC1 PMIC
DDR3L memory
Ethernet
UART4 for console
My power sequencing, PMIC wiring, and clock architecture are identical to the DK2 reference schematics.
All voltage rails appear stable except the DDR rails, and SDMMC signals look correct during boot.
However, when I try to boot from the SD card and monitor UART4, I only receive the following messages:
PANIC at PC : 0x2ffeada7
Exception mode = 0x00000016 at : 0x2ffeada7
There is nothing else printed afterward.
From the Cortex-A7 exception codes, 0x16 indicates an Undefined Instruction exception, and the address 0x2FFEADA7 lies inside the SYSRAM area. This suggests the crash happens very early, likely during TF-A execution.
My problem is that the MPU never seems to wake up properly, and I cannot identify the exact origin of the failure.
I would appreciate guidance on what typically causes this panic on custom STM32MP1 boards, and which subsystems I should verify first (DDR initialization, PMIC I2C configuration, reset lines, boot chains, etc.).
Thank you in advance for any support.
