rha@bunker.UUCP (Robert H. Averack) (01/21/89)
I am investigating how one can remotely cause a PC to reboot. Getting
the stimulus to the PC is clearly not the problem. The problem is getting
the software which recognizes the stimulus to issue a CTRL-ALT-DEL to MSDOS,
resulting in the reset and reboot.
Do any of you out there have any ideas? Thanks for your help.
{oliveb,yale,decvax,philabs}!bunker!rha
Bob Averack
Bunker Ramo, an Olivetti Company
Two Enterprise Drive - Shelton, Connecticut 06484 jborza%burgundy@Sun.COM (Jim_Borza) (01/21/89)
In article <4567@bunker.UUCP>, rha@bunker.UUCP (Robert H. Averack) writes: > > I am investigating how one can remotely cause a PC to reboot. Getting > the stimulus to the PC is clearly not the problem. The problem is getting > the software which recognizes the stimulus to issue a CTRL-ALT-DEL to MSDOS, > resulting in the reset and reboot. > You can reboot a PC with the following code. Assemble with MASM and convert to .COM via EXE2BIN. (It's a bit of overkill - but clean and reliable). ----------------- cut here --------------------------- PAGE ,132 TITLE REBOOT.COM Program reset the computer. COMMENT { This program will make a LONG call to location FFFF0(hex) which is the reset location for the 8088 CPU chip. Prior to doing that, the program also forces the word at location 00472(hex) to 1234(hex) which simulates a Ctrl-Alt-Del type of reboot and bypasses memory diagnostics in POST. { ;******************************************************************** ROM_BIOS_DATA segment at 40h ;location for RESET flag org 72h ;as setup by BIOS. RESET_FLAG label word ;word is 1234h during soft ROM_BIOS_DATA ends ;reboot. ;******************************************************************** REBOOT segment assume cs:REBOOT, ds:REBOOT, es:ROM_BIOS_DATA org 100h START: mov ax, 40h ;set up segment reg es: mov es, ax ;for ROM BIOS DATA mov ax, 01234h ;write 1234h to location 40:72 mov es:RESET_FLAG,ax xor ax,ax ;zero registers xor bx,bx xor cx,cx xor dx,dx xor si,si xor di,di push ax push ax push ax pop ds pop es popf ;clear flags call cs:BOOTER ;long call to reset location. mov ah,0 ;DOS exit (just for form - pro- int 21h ;gram should never get here!). ;-------------------------------------------------------------------- BOOTER dd 0FFFF0000h ;Reset location is FFFF0h. ;-------------------------------------------------------------------- REBOOT ends ;******************************************************************** end START ------------------------------ cut here ----------------------- Jim Borza - Sun Microsystems
figlik@ihlpl.ATT.COM (Jim Figlik) (01/23/89)
In article <4567@bunker.UUCP> rha@bunker.UUCP (Robert H. Averack) writes: > > I am investigating how one can remotely cause a PC to reboot. Getting >the stimulus to the PC is clearly not the problem. The problem is getting >the software which recognizes the stimulus to issue a CTRL-ALT-DEL to MSDOS, >resulting in the reset and reboot. > > Do any of you out there have any ideas? Thanks for your help. > > {oliveb,yale,decvax,philabs}!bunker!rha > Bob Averack > Bunker Ramo, an Olivetti Company > Two Enterprise Drive - Shelton, Connecticut 06484 Below is an assembler program that compiles to about 6 bytes, if I remember correctly, that will cause a boot on most machines. Have fun... Jim ------------- cut here -------------- name boot page 80,132 title 'Program to reboot a system' cseg segment para public 'CODE' assume cs:cseg,ds:cseg,es:cseg,ss:cseg org 100h ; COM file format entry: mp boot boot proc near int 19h boot endp ;end of the "procedure" cseg ends end entry ------------- cut here --------------
gbs@stratus.UUCP (George B. Smith) (01/24/89)
In article <86397@sun.uucp> jborza%burgundy@Sun.COM (Jim_Borza) writes: >In article <4567@bunker.UUCP>, rha@bunker.UUCP (Robert H. Averack) writes: >> I am investigating how one can remotely cause a PC to reboot. Getting >> the stimulus to the PC is clearly not the problem. The problem is getting >> the software which recognizes the stimulus to issue a CTRL-ALT-DEL to MSDOS, >> resulting in the reset and reboot. >> > >You can reboot a PC with the following code. >Assemble with MASM and convert to .COM via EXE2BIN. ... assembly lanuage program deleted >Jim Borza - Sun Microsystems Here is a Turbo C program to do the same thing: /* ** boot.c ** ** This small program will reboot an IBM PC or clone. If there are no ** command line arguments or there is a single argument of "warm", then ** a warm boot is performed. If there is a single argument of "cold", ** then a cold boot is performed. ** ** The mechanics of this feat result from the following convention ** supported by virtually every BIOS: ** ** If you jump into the BIOS with location 0040:0072H set to the ** magic quatity of 1234H, and jump to the entry point of the BIOS ** at location FFFF:0000h, the system will perform a warm boot ** (i.e., no power-on self-test, etc.). Putting anything else in ** that memory location will force a cold boot. */ #include <stdio.h> main(argc, argv) int argc; char *argv[]; { void (far *bye) (); int far *pt; pt = (int far *) 0x00000472L; /* location in memory for */ /* boot magic number */ if (argc < 2) *pt = 0x1234; /* warm boot magic number */ else if (argc == 2 && !strcmp("warm", argv[1])) *pt = 0x1234; /* warm boot magic number */ else if (argc == 2 && !strcmp("cold", argv[1])) *pt = 0x0000; /* cold boot magic number */ else { fprintf(stderr, "Usage: boot [warm | cold]\n"); exit(1); } bye = (void far *) 0x0ffff0000L; /* boot code in ROM BIOS */ (*bye)(); }