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|
;; $Id$
;; -----------------------------------------------------------------------
;;
;; Copyright 1994-2002 H. Peter Anvin - All Rights Reserved
;;
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, Inc., 53 Temple Place Ste 330,
;; Boston MA 02111-1307, USA; either version 2 of the License, or
;; (at your option) any later version; incorporated herein by reference.
;;
;; -----------------------------------------------------------------------
;;
;; bootsect.inc
;;
;; Load a boot sector (or other bootstrap program.)
;;
;; Unlike previous versions of this software, this doesn't require that
;; the length is 512 bytes. This allows PXE bootstraps and WinNT
;; "CD boot sectors" to be invoked.
;;
;
; Load a boot sector
;
is_bootsector:
%if IS_SYSLINUX || IS_MDSLINUX
; Transfer zero bytes
mov byte [CopySuper],0
jmp short load_bootsec
is_bss_sector:
; Transfer the superblock
mov byte [CopySuper],superblock_len
%endif
load_bootsec:
xchg dx,ax
shl eax,16
xchg dx,ax ; Now EAX = file length
mov edi, 100000h
push edi ; Save load address
call load_high
call crlf
sub edi,100000h
push edi ; Save length
%if IS_SYSLINUX || IS_MDSLINUX
movzx ecx,byte [CopySuper]
jcxz .not_bss
; For a BSS boot sector we have to patch.
mov esi,superblock
mov edi,100000h+(superblock-bootsec)
call bcopy
.not_bss:
%endif
xor edx,edx
xor esi,esi
%if IS_SYSLINUX || IS_MDSLINUX
; Restore original FDC table
mov eax,[OrigFDCTabPtr]
mov [fdctab],eax
mov dl,[DriveNumber]
mov si,PartInfo ; Partition info buffer
mov di,800h-18 ; Put partition info here
push di
mov cx,8 ; 16 bytes
xor ax,ax
rep movsw
pop si ; DS:SI points to partition info
%elif IS_ISOLINUX
mov dl,[DriveNo]
%elif IS_PXELINUX
mov byte [KeepPXE],1 ; Chainloading another NBP
call reset_pxe
%endif
xor bx,bx
;
; Entrypoint for "shut down and replace bootstrap" -- also invoked by
; the COMBOOT API. This routine expects two dword on the stack:
; linear address and length. Additionally, the values of ESI and EDX
; are passed on to the new bootstrap; the value of BX becomes the new
; DS.
;
replace_bootstrap:
;
; Prepare for shutting down
;
call vgaclearmode
;
; Set up initial stack frame (not used by PXE if keeppxe is set)
;
xor ax,ax
mov ds,ax
mov es,ax
%if IS_PXELINUX
test byte [KeepPXE],01h
jz .stdstack
les di,[InitStack] ; Reset stack to PXE original
jmp .stackok
%endif
.stdstack:
mov di,7C00h-44
push di
mov cx,22 ; 44 bytes
rep stosw
pop di
.stackok:
mov [es:di+28],edx
mov [es:di+12],esi
mov [es:di+6],bx
pop ecx ; Byte count to copy
pop esi ; Copy from...
cli
mov ax,es
mov ss,ax
movzx esp,di
mov edi,7C00h ; Copy to...
jmp bcopy_over_self
%if IS_SYSLINUX || IS_MDSLINUX
; Nothing
%else
is_bss_sector:
mov si,err_bssimage
call cwritestr
jmp enter_command
%endif
|
