EPIA-M + second serial port enabler
Niki Waibel
niki.waibel at newlogic.com
Mon Dec 15 04:53:01 CET 2003
i'd just like to confirm that the 2nd serial port on the epia-m
works if you do the modifications dave describes.
niki
On 09-Dec-2003 Dave Ashley wrote:
> In a previous email message
> http://www.clustermatic.org/pipermail/linuxbios/2003-November/005891.html
>
> I wrote
> In V1 the file to modify is src/superio/via/vt1211/setup_serial.inc
> That code sets up ttyS0 which is the VT1211's logical device 2. You
> want to add some similiar code for logical device 3 to get ttyS1 working.
>
> Assuming you want it to be at 2f8 you'd merge in these lines:
> OUTPNPADDR($7)
> OUTPNPDATA($3)
> /* set the enable in reg. 0x30 */
> OUTPNPADDR($0x30)
> OUTPNPDATA($0x1)
>
> /* Serial Port 2 Base Address (BEh) */
> OUTPNPADDR($0x60)
> OUTPNPDATA($0xbe)
> /* Serial Port 2 IRQ (03h) */
> OUTPNPADDR($0x70)
> OUTPNPDATA($0x3)
> /* Serial Port 2 Control */
> OUTPNPADDR($0xf0)
> OUTPNPDATA($0x2)
>
> ...then do the turn off pnp
> /* turn off PnP */
> OUTPNPADDR($0xaa)
>
> ...then duplicate the serial setup except the address goes from 3f8 -> 2f8
>
>
> There is a piece missing. I had to enable the second serial port on the VT1211
> and although linux recognized it, there was no serial activity on the lines.
>
> These lines need to be added during the vt1211 configuration:
>
> /* Allow serial port 2 (ldn 3) pins to come out */
> OUTPNPADDR($0x27)
> OUTPNPDATA($00)
>
> This has to be before the $0xaa write to turn off configuration mode.
>
> The default value on powerup for this register on the vt1211 is 0xff.
> There are multi purpose pins on the chip and this connects them to the second
> serial port.
>
> -Dave
More information about the coreboot
mailing list