On Mon, Oct 13, 2008 at 11:27 AM, Roman Yeryomin rj@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