Re: [ANNC] Linld 0.94 available

H. Peter Anvin (hpa@zytor.com)
Thu, 17 Jan 2002 09:09:48 -0800


Denis Vlasenko wrote:

>
> Ok, I brought old Turbo Debugger from home...
>
> It is not true on this box I type this message right now. 128 MB RAM.
> Under DOS:
> INT 15 AX=E801 returns carry set and AH=86 (have no BIOS manual here to look
> up this error code), other registers unchanged.

AH=86 is function not supported.

However, once again, you're running UNDER DOS. You probably should
query HIMEM.SYS for the memory size,

> INT 15 AH=88 returns AX=0.
> INT 15 AX=E820 - not tested, but obviously not working (or else kernels would
> boot fine without linld/loadlin kludge or kernel patch)
>
> So we have "triple-0" failure extracting mem size info from INT 15.

... because you're running under DOS.

>
> Just imagine old lovely 486 box never tested by manufacturer to work well
> with 64 MB of RAM. Joe Random Hacker plays Meg-o-Rama, but BIOS does not
> understand how that can be: int 15 fn 88 does not fit in 16-bit reg?!
> DOS does not boot, Joe says: well, Linux rulez, it will boot! but no...
>
> OTOH, CMOS reading hack most probably would not work either... memscan time?
>

By the time 64 MB RAM became supported, INT 15 AX=E801 was already
common. For pathological cases like you describe, it's "mem=" time.

-hpa

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/