Hi,
I am managing to replace BIOS with coreboot on a Rangeley evaluation board, but the serial console cannot display message after coreboot calls console_init() in src/southbridge/intel/fsp_rangeley/romstage.c.
The console is connected to UART0 (0x3f8), which has been verified by BIOS.
My configuration of coreboot includes: Mainboard: Intel->Mohon Peak CRB, which is the only choice for Rangeley FSP and microcode: downloaded from Intel FSP (https://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=23676). Payload: U-boot-x86 (should be irrelevant to payload, since coreboot just enters romstage)
I have checked that the UART0 registers should have been initialized. The TX FIFO should also work: after out something to 0x3f8, LSR will change. I have also checked some other registers might related to UART. The UART_CONT (0:1f.0-0x80) is in the default state (0x00000003). The GPIO Use Select is also in default state: GPIOS_13 is 0.
Is there any other register can block the UART output?
Besides, actually the coreboot finally run deeply. The post code changes from 47->66->67->69->...>72->73->77... and finally stop at 0xE2. But there's no console display so I cannot know where it stops.
Regards, Qingxin