bdn@phobos.cis.ksu.edu (Bryan D. Nehl) (03/16/90)
I was wondering if you all might be able to help me out. And point
out what in the world I am doing wrong. I have worked on this for
hours and haven't been able to figure this out. I would appreciate it
if someone could possibly send me (e-mail) a corrected copy of this code.
Thanks. And much appreciation. :-)
Bryan.
----8<-------8<----------------8<----------------8<-------------8<----------
TITLE Boot.asm
; This program should do a warm boot
DOSSEG
.MODEL TINY
.STACK 000H
.DATA
.CODE
; Code Starts Here -------------------------------
mov dx, 0
mov ds, dx
mov ax, 1234
mov [472], ax
; leave only jmp for a cold boot routine.
jmp far ptr 0ffffh:00000h
; Code Ends Here ----------------------------------
;/* ========== kodiak%kodiakpc.uucp@phobos.cis.ksu.edu =============+
;[ Big Bad Bear Beasties Inc. ][ Bryan Nehl ]
;[ kodiak@ksuvm.ksu.edu ][ bdn@phobos.cis.ksu.edu ]
;+___ ...!{rutgers|texbell}!ksuvax1!phobos.cis.ksu.edu!bdn _____ */
END ; ---------------------- End Of File ---------------------------------
--------8<---------------8<---------------------8<------------------8<-------jrh@mustang.dell.com (James R. Howard) (03/16/90)
In article <25FFF3C1.5C41@deimos.cis.ksu.edu>, bdn@phobos.cis.ksu.edu (Bryan D. Nehl) writes: > > I was wondering if you all might be able to help me out. And point > out what in the world I am doing wrong. I have worked on this for > hours and haven't been able to figure this out. I would appreciate it > if someone could possibly send me (e-mail) a corrected copy of this code. > Thanks. And much appreciation. :-) How about this??? TITLE Boot.asm ; This program should do a warm boot DOSSEG .MODEL TINY .STACK 000H .DATA .CODE ; Code Starts Here ------------------------------- mov ax, 0feh ; load mask into AX out 64h, ax ; write reset mask value to kbd controller cli ; disable interrupts hlt ; hlt ; Code Ends Here ---------------------------------- END ; ---------------------- End Of File --------------------------------- -------------------------------------------------------------- James Howard ..uunet!dell!mustang!jrh or jrh@mustang.dell.com The opinions stated are my own, and do not necessarily reflect the opinions of my employer, or anyone else. --------------------------------------------------------------
6600sirt@hub.UUCP (Mike O'Brien) (03/16/90)
From article <3015@uudell.dell.com>, by jrh@mustang.dell.com (James R. Howard): > How about this??? [...] > mov ax, 0feh ; load mask into AX > out 64h, ax ; write reset mask value to kbd controller [...] I have used this method before, but it is not at all reliable. I know of at least two computers at my work that this method will not work on, and they are both true-blue IBM's. What you are doing here is telling the keyboard controller to wait three microseconds and then reset the processor. The problem with this, as I understand it, is that on a 286 there is no way to get out of protected mode without resetting the processor. So programs that need to switch into and out of protected mode set a flag telling the processor where to jump after a memory reset. Not only are you not guaranteed that this flag will point to the boot code in ROM at any given time, you are not even guaranteed it will point there when the computer is first turned on. So, while this solution doesn't work in general, it might be the beginnings of a good solution. Hopefully someone reading this will point me to a book that explains in detail the flag I have referred to, so I can set it myself to the boot code. Michael O'Brien 6600sirt@ucsbuxa.ucsb.edu
mathrich@mthvax.cs.miami.edu (Rich Winkel) (03/16/90)
In <25FFF3C1.5C41@deimos.cis.ksu.edu> bdn@phobos.cis.ksu.edu (Bryan D. Nehl) writes:
%>I was wondering if you all might be able to help me out. And point
%>out what in the world I am doing wrong. I have worked on this for
%>hours and haven't been able to figure this out. I would appreciate it
%>if someone could possibly send me (e-mail) a corrected copy of this code.
%>Thanks. And much appreciation. :-)
%> mov dx, 0
%> mov ds, dx
%> mov ax, 1234 <<<---1234h
%> mov [472], ax <<<---472h
%>
%>; leave only jmp for a cold boot routine.
%>
%> jmp far ptr 0ffffh:00000h
Rich