diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S index e5c1733e59..313fa3ff96 100644 --- a/arch/x86/cpu/start.S +++ b/arch/x86/cpu/start.S @@ -128,6 +128,15 @@ car_init_ret: andl $0xfffffff0, %esp post_code(POST_START_STACK) + /* + * Debug UART is available here although it may not be plumbed out + * to pins depending on the board. To use it: + * + * call debug_uart_init + * mov $'a', %eax + * call printch + */ + /* Zero the global data since it won't happen later */ xorl %eax, %eax movl $GENERATED_GBL_DATA_SIZE, %ecx diff --git a/configs/minnowmax_defconfig b/configs/minnowmax_defconfig index e98f5eb5ce..a67597d8d6 100644 --- a/configs/minnowmax_defconfig +++ b/configs/minnowmax_defconfig @@ -24,3 +24,7 @@ CONFIG_FRAMEBUFFER_VESA_MODE_11A=y CONFIG_DM_RTC=y CONFIG_USE_PRIVATE_LIBGCC=y CONFIG_SYS_VSNPRINTF=y +CONFIG_DEBUG_UART=y +CONFIG_DEBUG_UART_NS16550=y +CONFIG_DEBUG_UART_BASE=0x3f8 +CONFIG_DEBUG_UART_CLOCK=1843200