Jonathan's Contribution

Linux Configuration

Henry's Serial Port, PPP and Diald Configuration

What do we want to achieve

There are four serial ports on Henry, presently one is used for the mouse, another connected to a modem for dial in and dial out access. Presently the other two serial ports are spare.

References

setserial's man page

Serial HOWTO

PPP HOWTO

Diald HOWTO

Setting the Serial Ports Correctly
This box has four serial ports the latter two operating off interrupts 9 and 11. The autoprobing function in the kernel does not probe for interrupts as this could create problems. Anyway I think autoprobing is a bad idea. Those responsible for looking after boxes should know were everything (peripherals included) and how to access them.

As the kernel boots, it throws up the following info as seen on dmesg.
----------------------------------------------------------
Serial driver version 4.27 with SHARE_IRQ enabled
ttyS00 at 0x03f8 (irq = 4) is a 16550A
ttyS01 at 0x02f8 (irq = 3) is a 16550A
ttyS02 at 0x03e8 (irq = 4) is a 16550A
ttyS03 at 0x02e8 (irq = 3) is a 16550A
----------------------------------------------------------
Which is great, in terms of io addresses, but makes totally the wrong assumptions about the interrupt vectors of the last two serial ports.

A fix for this using RedHat Linux is to create a file /etc/rc.d/rc.serial, that uses the setserial command to specify the address and irq's to the kernel. setserial is called from /etc/rc.d/rc.local.
>>>>>>>>>>>>>>>>/etc/rc.d/rc.serial
#!/bin/sh 
echo "Serial port reconfiguration:" 
/bin/setserial /dev/ttyS0 port 0x3f8 irq 4 uart 16550A spd_vhi 
/bin/setserial /dev/ttyS1 port 0x2f8 irq 3 uart 16550A spd_vhi
/bin/setserial /dev/ttyS2 port 0x3e8 irq 9 uart 16550A spd_vhi 
/bin/setserial /dev/ttyS3 port 0x2e8 irq 11 uart 16550A spd_vhi 
action "`/bin/setserial -b /dev/ttyS0`" /bin/true 
action "`/bin/setserial -b /dev/ttyS1`" /bin/true 
action "`/bin/setserial -b /dev/ttyS2`" /bin/true
action "`/bin/setserial -b /dev/ttyS3`" /bin/true
<<<<<<<<<<<<<<</etc/rc.d/rc.serial
The last four statements are used to print out the status on the screen during boot up showing the [ OK ] on the RHS. Also note that ttyS2 irq 9 shows up as irq 2 which is the hardware reassignment of irq 9 in the cascaded interrupt controllers on PC's.
Configuring PPP

Configuraing Diald

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