Re: Can't access I/O ports with dosemu 1.0.2

Stas Sergeev
2002-12-27T22:14:55Z

Hello.

Brad Rodriguez wrote:
> I see that COM1, COM2, and LPT1 are all listed in /proc/ioports, so
> I'll have to learn how to disable the kernel support.
Probably you can simply hack the
dosemu's ports.c and replace a
/proc/ioports there with /dev/null.
I don't know for sure will such a
cheat work or will it be safe, but
at least you can try.
As for disabling the in-kernel support,
you have to reconfigure/recompile
your kernel without a parport support,
or, which is better, if the support is
modular, just unload the relevant
modules and that should do the trick.

> But 0x320-0x327 (the
> EPROM emulator) is not listed in /proc/ioports and I don't seem able to
> access those ports either.
Yes, I also think it is a permissions
problem.

>> Yes, LPT is a weak part of dosemu unless
>> you do a simple printing.
> Unfortunately, I'm not using it to print.
And unfortunately dosemu doesn't have
a proper LPT support.

>> Why would the one require a direct
>> access to the COM ports? The support
>> for those is fairly complete under
>> dosemu.
> Perhaps I don't understand how these are supported under DOSEMU. The
Yep.

> programs I am using are not using BIOS calls to access the serial port.
> As far as I know, they include their own serial I/O drivers that talk
> directly
> to the bare metal. (Come to think of it, they probably also speak to
> the interrupt controller chip, and I don't know *how* I can allow that
> without completely corrupting the system.)
Please just stop making problems where
they don't exist. The LPT is problematic,
yes, but the PIC and Serials are fully
supported (except that the speed of the
emulated serial is not always sufficient).