[coreboot] alix.2c3 stops at mainboard_pre_payload: done

[Roman Yeryomin]

On Mon, Oct 13, 2008 at 11:27 AM, Roman Yeryomin <rj at tc.lv> wrote:
>> > >>> on system with native bios (tinybios):
>> > >>> cat /proc/tty/driver/serial
>> > >>> serinfo:1.0 driver revision:
>> > >>> 0: uart:16550A port:000003F8 irq:4 tx:945 rx:15 RTS|CTS|DTR|DSR|CD
>> > >>> 1: uart:16550A port:000002F8 irq:3 tx:0 rx:0 CTS|DSR|CD
>> > >>>
>> > >>> but on system with coreboot:
>> > >>> cat /proc/tty/driver/serial
>> > >>> serinfo:1.0 driver revision:
>> > >>> 0: uart:NS16550A port:000003F8 irq:4 tx:0 rx:0 RTS|DTR
>> > >>> 1: uart:unknown port:000002F8 irq:3
>>
>> What I find most interesting about the output above is how uart 1 is
>> identified differently when starting with coreboot. It would be good
>> to find out why.
>
> yes, that's the main question I think
>
>
>> > >> It seems whatever you have on that port is not asserting DTR,
>> > >> which is also odd.
>>
>> Please comment on this. What do you have connected to the serial
>> port?
>
> I'm trying to get serial console on it -- I connect to alix from my desktop
> with null modem cable
>
>> Does DTR on the Geode go high when your terminal software is
>> running?
>
> m?

Sorry, didn't really understand what you mean here.

>> > After init -> changes to Linux driver, or does it still use Int 10
>> > + Int 16 ?
>> > My BIOS does a redirect of these BIOS interrupts to the serial
>> > console.
>>
>> You can safely assume that no Linux kernel driver requires real mode
>> interrupts. This is an almost universal truth.
>>
>> In particular: no, the Linux serial driver does not use BIOS
>> interrupt services.
>
> maybe coreboot could try to use similar behavior? just to see what it gives?

So... any ideas what we can do with it?


Roman