Re: UEFI serial bootloader

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Tue, Jun 16, 2020 at 01:48:26PM +0300, Dima Veselov wrote:
> Greetings,
> 
> I have a server with IPMI serial console on COM2, which fails to show serial
> bootloader in UEFI mode. For testing purposes I am using iPXE stack with
> pxeboot_ia32 with console and serial options installed via installboot.
> 
> UEFI shows itself on every serial port and monitor simultaneously. If
> standard pxeboot is loaded it shows up on the same devices as UEFI, and
> the kernel continues on monitor only, but if pxeboot with com2 option is
> used - it does not show up anywhere, but the kernel works on com2.
> 
> I've tried to check the problem on KVM VM but it works as intended -
> UEFI on all devices, pxeboot on programmed device (monitor or serial),
> kernel continues on same as pxeboot.
> 
> It would be okay if kernel could have console= boot option, but as far
> as I know it does not, so there is no way I can set up both bootloader
> and kernel to serial device on real hardware.
> 
> Is there any clue to check why it happens or any way to debug pxeboot?

I've seen this on some supermicro hardware; AFAIK the bios swpped the
com1 and com2 ports. The solution was to force the boot loader to
use 0x3f8 as com1 (with the ioaddr option)

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--