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GRUB on system with NO gateA20

From: Liberty Young
Subject: GRUB on system with NO gateA20
Date: 22 Jul 2002 13:40:58 -0700

I'm working on with grub installed on a DiskOnChip on a Single Board
Computer (embedded pc). Grub will not boot past stage2 with no VGA
controller on the SBC. 

I have grub working just fine on the diskonchip when a VGA daughter
board is installed on the SBC. I have in my menu.lst the options for
serial output: 

I email the list earlier with the problem, thinking it could be related
to VGA....It's actually related to a GateA20 problem. The SBC doesn't
have a keyboard controller, but the daughter board does. 

I fixed the bug for my particular platform (a Elan SC520 based SBC).

It looks like that on x86 machines, grub uses Gate A20, instead of using
the PS/2 method via I/O port 92 for switching protected mode. 

Many embedded x86 boards do not have keyboard controllers; I am using
the AMD Elan SC520. Also, another popular embedded cpu is the Intel
386EX (which we use in another line of products). It too, does not have
a keyboard controller. 

I believe this to be a bug. 

Perhaps the code could be changed to use port 0x92 ? Any thoughts,

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