On Wed, Nov 5, 2008 at 2:01 AM, ron minnich rminnich@gmail.com wrote:
depending on how daring you feel, you can (I have done this) do an open of /dev/console IN THE KERNEL, and see what happens. But based on what we're seeing so far, I am pretty strongly convinced there is an interrupt issue here.
well.. I'm not really good programmer, but I can dig there and see what I can do, or you can give me some patch I can try... BTW some time ago, when I was starting to play with coreboot and already had this issue (there are posts in this list about month ago) I've asked Pascal Dornier (person behind pcengines - alix board maker) how he sets up uart in his bios (as seems like he wrote it himself) and here is what he replied (I've already posted this):
seems like there is a bug in coreboot and it's not setting uart the right way. I can see all the coreboot and kernel messages in console but right after init starts serial console is lost (linux keeps running normally). So.. could you share how you set up uarts in your tinyBIOS? Which UART[x]_MOD, UART[x]_DON and UART[x]_CONF bits you set?
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. Once the Linux kernel starts it has to take care of the serial console itself.
I didn't reply him because didn't know what to say. tinybios source code is available on pcengines website but it's written in assembler (and I don't understand anything there) -- maybe it can help somehow?
Roman