Subject: Re: IBM 7xx laptops available memory ...
To: None <rvb@sicily.odyssey.cs.cmu.edu>
From: Perry E. Metzger <perry@piermont.com>
List: port-i386
Date: 11/06/1997 16:10:28
The boot loader has been totally changed from 1.2 to 1.3....
Perry
rvb@sicily.odyssey.cs.cmu.edu writes:
> As an epilog to the previous discussion. I'm using NetBSD 1.2.
> The boot banner begins:
> >> NetBSD BOOT 639/23552 k [1.28]
> So someone knows that there is not 640K of memory here. (The
> boot program does an "int 12" to get the conventional memory
> size.)
>
> When the kernel starts running it does a:
> biosbasemem = (mc146818_read(NULL, NVRAM_BASEHI) << 8) |
> mc146818_read(NULL, NVRAM_BASELO);
> and gets 640.
>
> I've not an 1.3_alpha system to load onto the machine (hint ;-),
> but reading the latest locore.s, it certainly seems that the
> biosbasemem and biosextmem are fed in from the boot program
> which does the the right calculation.
>
> But sadly, it looks like the 1.2 boot loader also passes the
> correct mem info too, it's just not used.