On 08/06/2010 04:24 PM, Philippe Naudin wrote: > > Are you sure your expansion board is based on the "classical" UART > (8250 or 16550) ? Many add-on cards require specific modules. > Let's say I am 99% sure. It behaves exactly as a 16550, is listed in dmesg as 0000:03:05.0: ttyS0 at I/O 0xec00 (irq = 21) is a 16550A 0000:03:05.0: ttyS1 at I/O 0xe880 (irq = 21) is a 16550A and it works perfectly from Dom0. The only problem I face is transferring it to DomU. > This will not work on dom0 if the serial port is already shared, but > you can try it when no domU is running : > > $ for x in 0 1 2 3 4 ; do setserial /dev/ttyS$x ; done > /dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4 > /dev/ttyS1, UART: unknown, Port: 0x02f8, IRQ: 3 > /dev/ttyS2, UART: unknown, Port: 0x03e8, IRQ: 4 > /dev/ttyS3, UART: unknown, Port: 0x02e8, IRQ: 3 > /dev/ttyS4: No such file or directory I did not mention in the first message, but both serial interfaces from the card are perfectly usable from Dom0, from a standard kernel and from Windows ( the computer was previously used to monitor some industrial equipments, without adding any special drivers). [root at Dom0 ~]# for x in 0 1 2 3 4 ; do setserial /dev/ttyS$x ; done /dev/ttyS0, UART: 16550A, Port: 0xec00, IRQ: 21 /dev/ttyS1, UART: 16550A, Port: 0xe880, IRQ: 21 /dev/ttyS2, UART: unknown, Port: 0x03e8, IRQ: 4 /dev/ttyS3, UART: unknown, Port: 0x02e8, IRQ: 3 /dev/ttyS4: No such file or directory What I am not 100% sure is that we correctly blacklist all the modules related to serial interfaces in Dom0. But OTOH exactly the same config ( modulo ports / irq ) works with the onboard interface. manuel