- Phenomenon: When only the RESET_REQZ or MCU_PORZ signal is used for reset, the CPU can reset normally under U-Boot but freezes under Linux. A power cycle is required to restore normal operation. Rebooting via the "reboot" command in Linux works properly.
- Troubleshooting:
(1) System-related checks: Using the EVM development board, we flashed our own u-boot.img, dtb, Image, and rootfs.cpio. Pressing the SW3 button triggers a successful reboot. (tiboot3.bin and tispl.bin are the EVM's original files due to modifications to our DDR.)(2) Hardware-related checks:
- Measured bootmode levels, which are correct and remain unchanged during reset.
- Modified bootmode to UART boot. The system still freezes without output during reset, indicating no correlation with SPI flash.
- When only RESET_REQZ or MCU_PORZ is triggered, MCU_RESETSTAT shows output, but the CPU still freezes.
- Analysis:
We believe the CPU has responded to RESET_REQZ or MCU_PORZ (evidenced by the freeze and MCU_RESETSTAT output). Bootmode is ruled out as its levels remain stable. Linux System issues are eliminated since reset works normally on the EVM. SPI flash is excluded because the freeze persists in UART boot mode (no UART prints or CC output).No other factors affecting reset seem to exist, pointing to a potential CPU-related issue. The normal operation of soft reboot confirms that external components are functioning properly, leading us to suspect the CPU itself is freezing.We urgently need your assistance with this issue as we are in the board revision phase.
