Modem driver for pppd.

Matthew J Fletcher mfletcher at
Thu Mar 22 09:07:19 UTC 2001


> MJF> You could write a driver our you could use the one that i
> have written, i
> MJF> posted the
> MJF> sources to this mailist a few weeks ago, if you search the
> archives for PPPD
> MJF> you should find it, or i can send it again.

> Your modem driver contains a lot of code independent from the hardware.
> This code exists in the pppd/ and modem/.
> I have written a driver, which works with my hardware, and
> I need to know how it must interact with this independent code:

The pppd driver is mostly hardware independent, most of it deals with the
protocals that are used within ppp, chap, pap, mschap etc, and the various
agents that can be applied jan vackobson etc,. i fixed up all this stuff and
wrote a
proper control function pppmain (IIRC), that you just need to call.

as you know ppp is not tied to any particular hardware, i think that and
hardware stuff should be seperated out into another driver, such as the
termio for dev/tty etc, or dev/winmodem or dev/strange_embedded_modem etc.

> >1. What must driver do, when interrupt of received data from my
> port occures?
> >   Must it call 'pppinput' function for characters from this data?


> >2. What must driver do then it's 'read' function calls?
> >3. What must driver do then it's 'write' function calls?
> >   Must it simple send data to my port?

my pppd code used the termio stuff in rtems to read or write a char to
depending on how you set it up. If you had a modem attached to that port it
works as expected as the AT command set seems to be supported.

> >4. What must be done in it's 'ioctl' function?

these are just used to turn echo / blocking / non-blocking etc modes on off.


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