Hi, we use UART0 as main console data output. But for the SOL feature we need to redirect it.
According to COM-HPC-ALT User's guide it is possible to redirect console from UART0 to UART1 in BIOS.
We were trying to find it with different EDKII versions (v2.10.100.02, v2.09.100.00, v2.09.100.04) and there is no such an option.
Could you please, help us to understand what is wrong.
Thank you in advance!
Dear @Nikolai Motorin,
It’s not working out of the box because this board’s “COM/VGA serial” is built as a one-or-the-other mux, not an SOL wiring. For SOL to work, the BMC must be physically connected to the SoC’s console UART all the time, so it can read the serial bytes and forward them over IPMI.
Current state
Console output set to VGA_COM0 port(lable marked in the carrier board).
Not aligned with SOL path. You can only read either EDKII BIOS or BMC boot log locally by adjusting jumper settings(JP34).
To activate SOL we need to set it to COM1(lable marked in the carrier board). This one aligns with SOL path and below listed changes must be in the firmware.
Required Below Changes(Customized EDKII & BMC Firmware Required)
1. EDK2 (BIOS)
Redirect console output:
From SoC UART0(default) to SoC UART3
2. BMC
Read serial data:
From read SoC UART3 send it to BMC UART2(SOL compatible)
Package UART data as IPMI SOL messages
Send over LAN Plus interface
Above changes causes you can't use VGA COM0 as local serial port to read EDKII BIOS boot log instead you have to use COM1 port as local serial port, if you want activate SOL.
We ran into a similar situation on COM-HPC platforms. In our case, the documentation mentioned UART console redirection, but the actual BIOS menu did not expose a direct “UART0 → UART1” switch either.
What we found is that in some EDKII implementations, UART selection is abstracted under Console Input/Output Device Select rather than a physical UART index. Depending on the platform, UART0 and UART1 may already be internally mapped to specific COM devices, and fish it! the BIOS only allows enabling/disabling those logical devices, not explicit remapping.
Additionally, on some systems SOL requires that the BMC owns a specific UART at an earlier boot stage, which can prevent the option from appearing in BIOS even if it is documented. This seems to be more of a platform/firmware integration limitation than an EDKII version issue.
Is UART1 already reserved by the BMC for SOL at PEI/DXE stage, which would explain why the redirection option is hidden in BIOS?
