Date: Wed, 04 Dec 1996 13:32:36 +0000
From: Bill Currie <billc AT blackmagic DOT tait DOT co DOT nz>
Subject: Re: boot loader problem, need advise
To: Kuang-Chun Cheng <kccheng AT hep2 DOT phys DOT sinica DOT edu DOT tw>
Cc: djgpp AT delorie DOT com
Reply-to: billc AT blackmagic DOT tait DOT co DOT nz
Message-id: <32A57D74.3D16@blackmagic.tait.co.nz>
Organization: Tait Electronics NZ
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References: <199612032147 DOT QAA27120 AT delorie DOT com>

Kuang-Chun Cheng wrote:
> 
>         lidt   idt_lable
> 
> This instruction causes a reboot cycle.  That meant when I try to boot
> from floppy (with the image I wrote), system reboot again when it meet
> instruction lidt.  I did disable interrupt, NMI and try to reset 8259
> as Linux kernel did ...  No matter how I try, it just doesn't work :(

Did you remember to disable interrupts? Also check your code very
carefully for errors, because while switching modes, no matter what you
do there will be a sequence of instructions where the current idt is
invalid and any interrupts (or exceptions) will cause the cpu to
shutdown
(the motherboard detects this and resets the cpu).