Re: serial console puzzle

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

On Fri, Apr 30, 2021 at 05:23:54PM +0200, Manuel Bouyer wrote:
> On Fri, Apr 30, 2021 at 04:18:49PM +0100, Patrick Welche wrote:
> > On Fri, Apr 30, 2021 at 05:04:34PM +0200, Manuel Bouyer wrote:
> > > On Fri, Apr 30, 2021 at 03:44:46PM +0100, Patrick Welche wrote:
> > > > In /boot.cfg:
> > > > 
> > > > menu=Boot normally:rndseed /var/db/entropy-file;consdev com0,57600;boot
> > > > 
> > > > # installboot -ve /dev/rsd0a
> > > > File system:         /dev/rsd0a
> > > > Boot options:        timeout 5, flags 0, speed 57600, ioaddr 0, console com0
> > > > 
> > > > Yet in dmesg:
> > > > 
> > > > com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, 1-byte FIFO
> > > > com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, 1-byte FIFO
> > > > com1: console
> > > > 
> > > > (so I don't actually see anything)
> > > > 
> > > > (Wednesday's -current/amd64)
> > > > 
> > > > 
> > > > Thoughts?
> > > 
> > > one possibility is that the bios has com0 and com1 swapped.
> > > In some case I had to explicitely set ioaddr with installboot to have
> > > the serial console working.
> > 
> > I should have said: according to the BIOS "COM A" is 0x3f8, and "COM B"
> > is 0x2f8, so they are the right way around.
> 
> I've seen BIOSes report it the right way on in setup, but the wrong way
> to the boot loader.
> In such cases and explicit ioaddr did help.

Indeed - it did!

# installboot -ve /dev/rsd0a
File system:         /dev/rsd0a
Boot options:        timeout 5, flags 0, speed 57600, ioaddr 3f8, console com0

com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, 1-byte FIFO
com0: console
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, 1-byte FIFO

now for xen...


Thanks,

Patrick