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

[Roman Yeryomin]

On Sun, Oct 12, 2008 at 3:16 AM, Roman Yeryomin <leroi.lists at gmail.com> wrote:
> On Sat, Oct 11, 2008 at 8:33 PM, ron minnich <rminnich at gmail.com> wrote:
>>>
>>> while trying to resolve this problem I've noticed following:
>>>
>>> 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
>>>
>>
>> OK, this is kind of the problem I remember. If you have time go into
>> the kernel, IIRC, there is a test for some modem signal and the device
>> is not available otherwise. I am sorry to be so fuzzy but this was
>> seven years ago. It was a weird problem.
>
> you think this is kernel problem?
>
>> It seems whatever you have on that port is not asserting DTR, which is
>> also odd. Is there a loopback control in this part that routes DSR
>> back to DTR?
>
> Well, according to datasheet there is loopback control in cs5536 uart,
> but I don't think the problem is there.
> I've asked Pascal Dornier (pcengines) how he sets up uart in his bios
> but didn't receive an answer yet.
> I still think the problem is in coreboot (or libpayload)...

Pascal answered me:

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.


Roman