Baslinux mailing list

[sindi keesan <keesan AT sdf.lonestar.org>]

On Tue, 2 Nov 2004, James Miller wrote:

> I wrote to one of the FreeDOS developers with my "bug report" regarding
> memory mgmt programs in FreeDOS interfering with Xvesa once one boots to
> Linux using loadlin.  He, in turn, submitted it to the right people (those
> maintaining/developing memory mgmt progs, I assume) and, as I was afraid
> he might, asked for further testing.  Don't know when/if I'll have time
> for such testing--he wanted to know which of the two, or whether both,

Regarding himem.sys and emm386.exe:

I read in a SuSE book that if you boot DOS with himem.sys you also need to 
use emm386.exe or linux will not boot with loadlin, but you can boot linux 
with neither.  So I don't know how one would test them separately (just 
himem.sys won't boot linux, just emm386 won't boot DOS).

Win9X smartdrv also interfered and the FreeDOS equivalent should be 
tested.  Win9X with himem.sys and emm386 wihtout smartdrv works with 
Xvesa.


> case the problem, and what error message Xvesa gives.  If anyone cares to
> test this more, please submit feedback on it, which I will then forward to
> the FreeDOS people.  Otherwise, that'll have to wait until I can find some
> time to devote to it.

I will try to do this soon by booting with a FreeDOS floppy boot disk and 
himem.sys alone, himem.sys with emm386.exe, then also combinations with
smartdrv.

> Finally, let me just include a bit of information this developer gave in
> response to my bug report, in case it might be interesting to those
> facing this memory mgmt problem:
>
> Eric Auer <eric AT CoLi.Uni-SB.DE> wrote:
>
> Hi James, forwarding to Tom and Michael, maybe they have a comment...
>
> <snip>
>
> Please distinguish HIMEM+EMM386 from only HIMEM. The former involves
> mapping, and it might happen that the memory area for the VESA framebuffer
> is not explicitly mapped by EMM386 by default. Instead, it might expect
> DOS programs (e.g. games) to request such mapping manually. LOADLIN does
> not ask for special mapping by itself. If you only load HIMEM and still
> have problems, the background could be either A20 handling (low probability,
> as the rest of Linux works okay for you) or some hooked interrupts. With
> MEMTEST86+ (www.memtest.org) I fount that it is a problem that HIMEM hooks
> int 15 (and so does EMM386 and even MKEYB)...: MEMTEST asks int 15 for the
> installed memory size and memory map, and uses int 15 for APM power mgmt
> control. HIMEM changes the reported memory map, and more importantly it
> might get overwritten by MEMTEST before getting called, so int 15 would hang.

I hope my partner can follow this.  We have memtest86 now.  I will sic him 
on this problem.  He enjoyed figuring out why BL2 floppy installation 
would not work for us with certain DOSes.

> There is no well-defined interface to uninstall HIMEM or EMM386 completely,
> but LOADLIN seems to do its best, otherwise it would not be able to load
> Linux while DOS memory management is loaded.
>
> Please give some more details, like contents of your config / autoexec and
> the exact error message from Xvesa (plus later, on demand, some contents of
> /proc status information and other log files as needed...).
> _______________________________________________

Sindi
>

keesan AT sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org