Re: Linus' laptop and Num lock status
From: Randy Dunlap
Date: Sun Feb 18 2007 - 13:00:10 EST
On Sun, 18 Feb 2007 17:04:01 +0100 Jean Delvare wrote:
> On Thu, 15 Feb 2007 06:34:35 -0800, H. Peter Anvin wrote:
> > Jean Delvare wrote:
> > > On x86, the BIOS led state can be read from byte 0x97 the BIOS RAM. The
> > > BIOS RAM is mapped at 0x400 so all we need to do is to one byte from
> > > RAM (offset 0x497). This is how Suse's hwinfo does.
> > Perhaps that's what Suse does, but the proper address is 0x417.
> > 0x497 is the rarely-used LPT2 timeout counter.
> Still, the information printed by hwinfo is correct, I've tested it
> myself. Is there some publicly available documentation about the x86
> BIOS RAM mapping?
0x40:0x17 is called "keyboard control" and
0x40:0x97 is called "keyboard LED flags" in the IBM Personal
System/2 and Personal Computer BIOS Interface Technical Reference,
Section 3: Data Areas and ROM Tables.
<internet_search> /bios data areas tables/ ::
*** Remember to use Documentation/SubmitChecklist when testing your code ***
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/