mkinitrd-magellan/isolinux/bootsect.inc

;; $Id: bootsect.inc,v 1.1 2007-09-01 22:44:04 niro Exp $
;; -----------------------------------------------------------------------
;;   
;;   Copyright 1994-2005 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
		mov [trackbuf+4],edi	; Copy from this address
		push edi		; Save load address
		xor dx,dx		; No padding
		call load_high
		call crlf

		sub edi,100000h
		mov [trackbuf+8],edi	; Save length

		mov eax,7C00h		; Entry point
		mov [trackbuf],eax	; Copy to this address
		mov [EntryPoint],eax	; Jump to this address when done

%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 || IS_EXTLINUX
		; 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

;
; replace_bootstrap for the special case where we have exactly one
; descriptor, and it's the first entry in the trackbuf
;

replace_bootstrap_one:
		push word trackbuf		; Address of descriptor list
		push word 1			; Length of descriptor list
		; Fall through

; 
; Entrypoint for "shut down and replace bootstrap" -- also invoked by
; the COMBOOT API.  This routine expects two words on the stack:
; address of the copy list (versus DS) and count.  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 - we use the PXE stack then.)
		; AFTER THIS POINT ONLY .earlybss IS AVAILABLE, NOT .bss
		;
		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 ax			; Copy list count
		pop bx			; Copy from...

		cli
		mov cx,es
		mov ss,cx
		movzx esp,di

		jmp shuffle_and_boot

%if IS_SYSLINUX || IS_MDSLINUX
		; Nothing
%else
is_bss_sector:
		mov si,err_bssimage
		call cwritestr
		jmp enter_command
%endif
1	;; $Id: bootsect.inc,v 1.1 2007-09-01 22:44:04 niro Exp $
2	;; -----------------------------------------------------------------------
3	;;
4	;; Copyright 1994-2005 H. Peter Anvin - All Rights Reserved
5	;;
6	;; This program is free software; you can redistribute it and/or modify
7	;; it under the terms of the GNU General Public License as published by
8	;; the Free Software Foundation, Inc., 53 Temple Place Ste 330,
9	;; Boston MA 02111-1307, USA; either version 2 of the License, or
10	;; (at your option) any later version; incorporated herein by reference.
11	;;
12	;; -----------------------------------------------------------------------
13
14	;;
15	;; bootsect.inc
16	;;
17	;; Load a boot sector (or other bootstrap program.)
18	;;
19	;; Unlike previous versions of this software, this doesn't require that
20	;; the length is 512 bytes. This allows PXE bootstraps and WinNT
21	;; "CD boot sectors" to be invoked.
22	;;
23
24	;
25	; Load a boot sector
26	;
27	is_bootsector:
28	%if IS_SYSLINUX \|\| IS_MDSLINUX
29	; Transfer zero bytes
30	mov byte [CopySuper],0
31	jmp short load_bootsec
32
33	is_bss_sector:
34	; Transfer the superblock
35	mov byte [CopySuper],superblock_len
36	%endif
37	load_bootsec:
38	xchg dx,ax
39	shl eax,16
40	xchg dx,ax ; Now EAX = file length
41	mov edi, 100000h
42	mov [trackbuf+4],edi ; Copy from this address
43	push edi ; Save load address
44	xor dx,dx ; No padding
45	call load_high
46	call crlf
47
48	sub edi,100000h
49	mov [trackbuf+8],edi ; Save length
50
51	mov eax,7C00h ; Entry point
52	mov [trackbuf],eax ; Copy to this address
53	mov [EntryPoint],eax ; Jump to this address when done
54
55	%if IS_SYSLINUX \|\| IS_MDSLINUX
56	movzx ecx,byte [CopySuper]
57	jcxz .not_bss
58
59	; For a BSS boot sector we have to patch.
60	mov esi,superblock
61	mov edi,100000h+(superblock-bootsec)
62	call bcopy
63
64	.not_bss:
65	%endif
66
67	xor edx,edx
68	xor esi,esi
69	%if IS_SYSLINUX \|\| IS_MDSLINUX \|\| IS_EXTLINUX
70	; Restore original FDC table
71	mov eax,[OrigFDCTabPtr]
72	mov [fdctab],eax
73
74	mov dl,[DriveNumber]
75	mov si,PartInfo ; Partition info buffer
76	mov di,800h-18 ; Put partition info here
77	push di
78	mov cx,8 ; 16 bytes
79	xor ax,ax
80	rep movsw
81	pop si ; DS:SI points to partition info
82	%elif IS_ISOLINUX
83	mov dl,[DriveNo]
84	%elif IS_PXELINUX
85	mov byte [KeepPXE],1 ; Chainloading another NBP
86	call reset_pxe
87	%endif
88	xor bx,bx
89
90	;
91	; replace_bootstrap for the special case where we have exactly one
92	; descriptor, and it's the first entry in the trackbuf
93	;
94
95	replace_bootstrap_one:
96	push word trackbuf ; Address of descriptor list
97	push word 1 ; Length of descriptor list
98	; Fall through
99
100	;
101	; Entrypoint for "shut down and replace bootstrap" -- also invoked by
102	; the COMBOOT API. This routine expects two words on the stack:
103	; address of the copy list (versus DS) and count. Additionally,
104	; the values of ESI and EDX are passed on to the new bootstrap;
105	; the value of BX becomes the new DS.
106	;
107	replace_bootstrap:
108	;
109	; Prepare for shutting down
110	;
111	call vgaclearmode
112
113	;
114	; Set up initial stack frame (not used by PXE if keeppxe is
115	; set - we use the PXE stack then.)
116	; AFTER THIS POINT ONLY .earlybss IS AVAILABLE, NOT .bss
117	;
118	xor ax,ax
119	mov ds,ax
120	mov es,ax
121
122	%if IS_PXELINUX
123	test byte [KeepPXE],01h
124	jz .stdstack
125	les di,[InitStack] ; Reset stack to PXE original
126	jmp .stackok
127	%endif
128	.stdstack:
129	mov di,7C00h-44
130	push di
131	mov cx,22 ; 44 bytes
132	rep stosw
133	pop di
134	.stackok:
135
136	mov [es:di+28],edx
137	mov [es:di+12],esi
138	mov [es:di+6],bx
139
140	pop ax ; Copy list count
141	pop bx ; Copy from...
142
143	cli
144	mov cx,es
145	mov ss,cx
146	movzx esp,di
147
148	jmp shuffle_and_boot
149
150	%if IS_SYSLINUX \|\| IS_MDSLINUX
151	; Nothing
152	%else
153	is_bss_sector:
154	mov si,err_bssimage
155	call cwritestr
156	jmp enter_command
157	%endif