I have a small based atom machine. There are four serial ports on the machine. dmesg | grep tty shows 0, 1, 2 and 3. 2 and 3 are on interrupt 10 -and they worked.

going into the BIOS COM ports 0 and 1 are also on IRQ 10 and not the standard 3,4. BIOS cannot set anything but IRQ 10, 11 for serial ports. Odd...

So COM 0 and 1 dont work right away... I had to put this in the boot script.

setserial /dev/ttyS1 irq 10 port 0x2e8 setserial /dev/ttyS0 irq 10 port 0x3e8

now they seem to work.

I have no idea why the bios will not have IRQ 3 and 4 for com ports but I was surprised linux did not inquire from the bios and use it.

Should it get that from the BIOS - or - just leave the manual setting and move on...

jerry