From: "deckerben" <bdeck AT lycos DOT co DOT uk>
Newsgroups: comp.os.msdos.djgpp
References: <Pine DOT HPX DOT 4 DOT 21 DOT 0304081332480 DOT 11022-100000 AT fajnm1 DOT am DOT ub DOT es> <054d01c2fdc9$ffa76710$0600000a AT broadpark DOT no>
Subject: Re: porting PCI card driver from NT to DOS
Date: Tue, 8 Apr 2003 17:04:50 +0200
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"Gisle Vanem" <giva AT bgnett DOT no> wrote in message
news:054d01c2fdc9$ffa76710$0600000a AT broadpark DOT no...
> "Octavi Fors" <ofors AT am DOT ub DOT es> said:
>
> > I understand porting to DOS would be complex, but do you it would
> > be possible, in theory.
>
> Yes, of course.
>
> > In particular, is djgpp able to handle PCI bus 32-bits I/O interrupts?
> > Which djgpp command could handle this?
>
> AFAIK, interrupts coming from a PCI device is handled in the same
> way as coming from a ISA device. So you can use the "normal"
> interrupt hooking (_go32_dpmi_set_protected_mode_interrupt_vector()
> or _go32_dpmi_allocate_real_mode_callback_iret).

The problem is that the resulting port will not work for any DJGPP user
under NT/W2K/XP because the NT kernel locks all PCI ports and will not allow
direct access via DOS or DPMI. This is the biggest problem we were trying to
crack with the MSDOS Mesa port... we ended up just supporting VGA (which is
all NT will allow - even if I have a good on-board VESA chip).


> You biggest problem would be to query the PCI-BIOS where
> the IRQ and I/O ports are assigned. Look at my libpcap port
> for an PCI / BIOS32 example.
> http://www.bgnett.no/~giva/pcap/libpcap.zip

Gisle, have you ever tried to port the pcap library from www.tcdump.org to
DJGPP-Watt32? The API it uses seems to be the one of choice ammong some of
the GNU developers.
I was successful porting it using the  --with-pcap=bpf configure option, and
replacing the distribution copy of bpf\net\bpf.h with the one from the
Watt32 distribution.
Nevertheless, I have encountered two problems:
1. pcap_findalldevs crashes (at least under W2K).
2. appearant lack of any system device name for network (like /proc/net/dev)

The third possibility would be if Watt-32 supported an ifaddrs interface
(getifaddrs & freeifaddrs). Do you know if this is possible?


Ben