Debugging Skills

Enable log output

Our UEFI provides 4 ways currently for getting UEFI logs.

  USE_SCREEN_FOR_SERIAL_OUTPUT    = 0
  USE_UART_GENI_FOR_SERIAL_OUTPUT = 0
  USE_UART_DM_FOR_SERIAL_OUTPUT   = 0
  USE_MEMORY_FOR_SERIAL_OUTPUT    = 0

Only one of them can be enabled at the same time.

USE_SCREEN_FOR_SERIAL_OUTPUT

Set to 1 to enable serial output via screen. Logs will be printed to screen directly. This way is very useful for devices without a UART.

USE_UART_GENI_FOR_SERIAL_OUTPUT

Set to 1 to enable serial output via a real serial port. Logs will be printed to the geni uart address at gAndromedaPkgTokenSpaceGuid.PcdUartSerialBase which is defined in Silicon/QC/XXX/QcomPkg/QcomPkg.dsc.inc.

USE_UART_DM_FOR_SERIAL_OUTPUT

Similar to USE_UART_GENI_FOR_SERIAL_OUTPUT. It's used for older Qualcomm platforms like msm8996.

USE_MEMORY_FOR_SERIAL_OUTPUT

Set to 1 to print logs to pstore memory. It's useful when you have JTAG or EUD enabled on your device. The log output region is defined in your device's Library/PlatformMemoryMapLib/PlatformMemoryMapLib.c.
The region must be named PStore like this:

{"PStore", <StartAddress>, <Size>, AddMem, MEM_RES, SYS_MEM_CAP, Reserv, WRITE_THROUGH_XN},