[LinuxBIOS] get some output on serial console of commel lv671 board, but not readable one

Corey Osgood corey.osgood at gmail.com
Fri Jun 15 21:51:44 CEST 2007

Dieter Bloms wrote:
> Hi,
> On Fri, Jun 15, Uwe Hermann wrote:
>> On Fri, Jun 15, 2007 at 08:08:59PM +0200, Dieter Bloms wrote:
>>> Hi,
>>> I managed to get some stuff on my serial out, when I switch on my
>>> commell lv671 board with i82801 chip and w83627hf superio, but it is not
>>> readable. The most of it are ? inverse colour like :
>>> ����������������SSQ����|���Ӌ����E���������������L�������E�����������i�������������������������iT���������������i�������[10;1H�����������������Ϝ������������������Ϭ�������������������������ϼԜ�������������������Ϭ�����������������������������c߈�w�H��
>>> I use 115200,8N1, which works fine, if I boot into linux with original
>>> bios.
>>> Has anybody seen those output and know what may be wrong ?
>> Can you post the complete patch you used for your code? It's hard to
>> say if we don't know what code exactly you used.
>> Maybe the port is incorrect, try 0x2e, 0x4e, 0x3f0 etc in auto.c.
> Ok, I will try the other ones (I used 0x4e)
> I've attached one diff with all my changes.

In the future, "svn diff" is much easier to use and more readable.

> +
> +	device_t dev;
> +	/* enable the decoding of superio ranges to the LPC interface */
> +	dev = pci_locate_device(PCI_ID(0x8086, 0x24c0), 0);
> +	pci_write_config16(dev, 0xE6, 0x3cff);

Please add this line:

pci_write_config16(dev, 0xE0, 0x10);

and see if it helps. If it doesn't, remove that block entirely, and try
again (this shouldn't be necessary for basic early serial anyways)

also this:
> +    enable_smbus ();
shouldn't have a space. If all else fails, try doing this before your
serial, I'm not sure why, just call it a hunch.


More information about the coreboot mailing list