Import backup from 2003-08-10

bootdef.inc

@@ -1,7 +1,9 @@
 
-%define FAT_SEG 0x07E0			;right after boot sector
+%define BOOT_FAT_SEG 0x07E0			;right after boot sector
-%define ROOT_SEG 0x0900			;right after FAT
+%define BOOT_ROOT_SEG 0x0900			;right after FAT
-%define STAGE2_SEG 0x0AC0		;right after ROOT_DIR
+%define BOOT_STAGE2_SEG 0x0B00			;right after KERNEL_SEG
-%define KERNEL_ADD 0x100000		;final pmode kernel destination - physical
+%define BOOT_STAGE2_ADD 0xB000			;address of stage2 to jump to, org at
+%define BOOT_KERNEL_SEG 0x0AC0			;right after ROOT_DIR
+%define BOOT_KERNEL_ADD 0x100000		;final pmode kernel destination - physical
 
 

kernel.asm

@@ -1,14 +1,10 @@
 
-bits 16
+bits 32
 
-org	0xac00
+org	0x100000
 
-	mov	ax, 0xb800
+	mov	esi, msg
-	mov	es, ax
+	mov	edi, 0xb8000
-	xor	ax, ax
-	mov	ds, ax
-	mov	si, msg
-	xor	di, di
 
 msg_loop:
 	lodsb
@@ -24,5 +20,5 @@ msg_done:
 	jmp	$
 
 msg:
-	db	"This kernel is located at 0x100000!", 0
+	db	"This kernel is located at 0x100000! Aren't you glad?", 0
 

stage1.asm

@@ -34,9 +34,10 @@ brFSID          DB      'FAT12   '      ; 0036h - File System ID
 
 start:
 	;dl=drive number, save it!
+	xor	ax, ax
+	mov	ds, ax
 	mov	[brDrive], dl
 	cli
-	xor	ax, ax
 	mov	ss, ax
 	mov	sp, 0x7Bfe		;right under boot sector
 	sti
@@ -90,7 +91,7 @@ unreal:
 	mov	cx, 0x0002
 	xor	dh, dh
 	mov	dl, [brDrive]
-	mov	bx, FAT_SEG
+	mov	bx, BOOT_FAT_SEG
 	mov	es, bx
 	xor	bx, bx
 	int	0x13
@@ -99,13 +100,13 @@ unreal:
 	mov	cx, 0x0002		;cyl/sect
 	mov	dh, 0x01		;head
 	mov	dl, [brDrive]		;drive
-	mov	bx, ROOT_SEG
+	mov	bx, BOOT_ROOT_SEG
 	mov	es, bx
 	xor	bx, bx
 	int	0x13
 
 ;k now read root directory
-	mov	bx, ROOT_SEG
+	mov	bx, BOOT_ROOT_SEG
 	mov	ds, bx
 	xor	si, si			;k now ds:si points to beginning of root directory
 	mov	es, si
@@ -118,7 +119,6 @@ loop_compare:
 loop_name:
 	cmpsb
 	loopz	loop_name
-	;cmp	cx, 0
 	jnz	goon			;cx didn't get to zero, bad file
 	pop	si
 	pop	cx
@@ -133,13 +133,12 @@ error:
 	jmp	$			;halt! no kernel file found!
 
 found_file:				;ds:si points to root dir entry
-	mov	ax, STAGE2_SEG
+	mov	ax, BOOT_STAGE2_SEG
 	mov	es, ax
 
 	mov	ax, [ds:si+26]
-	mov	bx, FAT_SEG
+	mov	bx, BOOT_FAT_SEG
 	mov	ds, bx			;ds points to beginning of FAT
-	xor	bx, bx
 	xor	di, di
 
 readstage2_loop:
@@ -147,22 +146,14 @@ readstage2_loop:
 	jg	readstage2_done
 	inc	di
 	push	ax
-	push	bx
 	call	getCHSfromCluster
-	pop	bx
-	push	bx
 	mov	ax, 0x0201
-	mov	dl, [brDrive]
+	mov	dl, 0			;[brDrive]
-	int	0x13
-	pop	bx
-	add	bx, 512
-	cmp	bx, 0
-	jne	readstage2_goon
-	mov	bx, es
-	add	bx, 0x0100
-	mov	es, bx
 	xor	bx, bx
-readstage2_goon:
+	int	0x13
+	mov	bx, es
+	add	bx, 0x0020
+	mov	es, bx
 	pop	ax			;current logical cluster #
 
 	mov	cx, ax			;cx=logical cluster
@@ -184,7 +175,7 @@ got_cluster:
 
 readstage2_done:
 
-	jmp	0:(STAGE2_SEG*16)
+	jmp	0:BOOT_STAGE2_ADD
 
 ;------------------------------------------------------
 getCHSfromCluster:

stage2.asm

@@ -1,114 +1,13 @@
 
-%define FAT_SEG 0x07E0			;right after boot sector
+%include "bootdef.inc"
-%define ROOT_SEG 0x0900			;right after FAT
-%define KERNEL_SEG 0x0AC0		;right after ROOT_DIR
-%define KERNEL_ADD 0x100000		;1mb - kernel final address
 
 [bits 16]
 
-org 0x7c00
+org BOOT_STAGE2_ADD
 
-	jmp short start
-
-; --------------------------------------------------
-; data portion of the "DOS BOOT RECORD"
-; ----------------------------------------------------------------------
-brINT13Flag     DB      90H             ; 0002h - 0EH for INT13 AH=42 READ
-brOEM           DB      'MSDOS5.0'      ; 0003h - OEM ID - Windows 95B
-brBPS           DW      512             ; 000Bh - Bytes per sector
-brSPC           DB      1               ; 000Dh - Sector per cluster
-brSc_b4_fat	DW      1               ; 000Eh - Reserved sectors
-brFATs          DB      2               ; 0010h - FAT copies
-brRootEntries   DW      0E0H		; 0011h - Root directory entries
-brSectorCount   DW      2880		; 0013h - Sectors in volume, < 32MB
-brMedia         DB      240		; 0015h - Media descriptor
-brSPF           DW      9               ; 0016h - Sectors per FAT
-brSc_p_trk	DW      18              ; 0018h - Sectors per head/track
-brHPC           DW      2		; 001Ah - Heads per cylinder
-brSc_b4_prt	DD      0               ; 001Ch - Hidden sectors
-brSectors       DD      0	        ; 0020h - Total number of sectors
-brDrive		DB      0               ; 0024h - Physical drive no.
-		DB      0               ; 0025h - Reserved (FAT32)
-		DB      29H             ; 0026h - Extended boot record sig (FAT32)
-brSerialNum     DD      404418EAH       ; 0027h - Volume serial number
-brLabel         DB      'HOS 0.1.1  '   ; 002Bh - Volume label
-brFSID          DB      'FAT12   '      ; 0036h - File System ID
-;------------------------------------------------------------------------
-
-start:
-	;dl=drive number, save it!
-	mov	[brDrive], dl
-	cli
-	xor	ax, ax
-	mov	ss, ax
-	mov	sp, 0x7Bfe		;right under boot sector
-	sti
-
-	mov	ax, 0xb800
-	mov	ds, ax
-	mov	es, ax
-
-	xor	di, di
-	mov	ax, 0x0700
-	mov	cx, 2000
-cls:
-	stosw
-	loop	cls
-
-enable_a20:
-	in	al, 0x64
-	test	al, 2
-	jnz	enable_a20
-	mov	al, 0xD1
-	out	0x64, al
-ea20_2:	in	al, 0x64
-	and	ax, byte 2
-	jnz	ea20_2
-	mov	al, 0xDF
-	out	0x60, al
-
-unreal:
-	xor	ax, ax
-	mov	es, ax
-	mov	ds, ax
-
-	lgdt	[gdtr]		;load gdt
-	cli
-	push	es
-	push	ds		;save segment values
-	mov	ebx, cr0
-	inc	bl
-	mov	cr0, ebx	;pmode!
-	mov	ax, KERNEL_DATA
-	mov	es, ax
-	mov	ds, ax		;load segment limits
-	dec	bl
-	mov	cr0, ebx	;back to real mode!
-	pop	ds
-	pop	es		;segments back, with 4gb limits!
-	sti
-
-;now lets read in the FAT and root directory so we can search for the kernel file...
-	mov	ax, 0x0209		;FAT1
-	mov	cx, 0x0002
-	xor	dh, dh
-	mov	dl, [brDrive]
-	mov	bx, FAT_SEG
-	mov	es, bx
-	xor	bx, bx
-	int	0x13
-
-	mov	ax, 0x020E		;root directory
-	mov	cx, 0x0002		;cyl/sect
-	mov	dh, 0x01		;head
-	mov	dl, [brDrive]		;drive
-	mov	bx, ROOT_SEG
-	mov	es, bx
-	xor	bx, bx
-	int	0x13
 
 ;k now read root directory
-	mov	bx, ROOT_SEG
+	mov	bx, BOOT_ROOT_SEG
 	mov	ds, bx
 	xor	si, si			;k now ds:si points to beginning of root directory
 	mov	es, si
@@ -120,7 +19,7 @@ loop_compare:
 	mov	cx, 11
 loop_name:
 	cmpsb
-	loopnz	loop_name
+	loopz	loop_name
 	jnz	goon			;cx didn't get to zero, bad file
 	pop	si
 	pop	cx
@@ -134,36 +33,35 @@ error:
 	jmp	$			;halt! no kernel file found!
 
 found_file:				;ds:si points to root dir entry of kernel file
-	mov	ax, KERNEL_SEG
-	mov	es, ax
-
 	mov	ax, [ds:si+26]
-	mov	bx, FAT_SEG
+	mov	bx, BOOT_FAT_SEG
 	mov	ds, bx			;ds points to beginning of FAT
-	xor	bx, bx
+	mov	edi, BOOT_KERNEL_ADD
-	xor	di, di
 
 readkernel_loop:
 	cmp	ax, 0xff7
 	jg	readkernel_done
-	inc	di
 	push	ax
-	push	bx
 	call	getCHSfromCluster
-	pop	bx
-	push	bx
 	mov	ax, 0x0201
-	mov	dl, [brDrive]
+	mov	dl, 0			;[brDrive]
-	int	0x13
+	mov	bx, BOOT_KERNEL_SEG
-	pop	bx
-	add	bx, 512
-	cmp	bx, 0
-	jne	readkernel_goon
-	mov	bx, es
-	add	bx, 0x0100
 	mov	es, bx
 	xor	bx, bx
-readkernel_goon:
+	int	0x13
+	mov	cx, 256
+	xor	ax, ax
+	mov	es, ax
+	mov	esi, BOOT_KERNEL_SEG*16
+copykernel_loop:
+	mov	ax, [es:esi]
+	mov	[es:edi], ax
+	inc	esi
+	inc	esi
+	inc	edi
+	inc	edi
+	loop	copykernel_loop
+
 	pop	ax			;current logical cluster #
 
 	mov	cx, ax			;cx=logical cluster
@@ -183,25 +81,7 @@ odd_cluster:
 got_cluster:
 	jmp	readkernel_loop
 
-readkernel_done:			;now copy kernel to final location in KERNEL_ADD!
+readkernel_done:
-	xor	ecx, ecx
-	mov	cx, di			;cx=# of 512byte sectors loaded
-	shl	ecx, 9			;ecx=ecx*512
-
-	mov	ax, KERNEL_SEG
-	mov	ds, ax
-	xor	esi, esi
-	xor	ax, ax
-	mov	es, ax
-	mov	edi, KERNEL_ADD
-movekernel_loop:
-	mov	al, [ds:esi]
-	inc	esi
-	mov	[es:edi], al
-	inc	edi
-	dec	ecx
-	cmp	ecx, 0
-	jne	movekernel_loop
 
 	jmp	go_pm
 
@@ -229,6 +109,7 @@ gdtr:
 gdt:
 	dd	0
 	dd	0
+
 KERNEL_CODE equ $-gdt
 	db	0xff		;limit	7:0
 	db	0xff		;limit	15:8
@@ -267,7 +148,7 @@ pmode:
 	mov	ax, KERNEL_DATA
 	mov	es, ax
 	mov	ds, ax
-	jmp	KERNEL_CODE:KERNEL_ADD
+	jmp	KERNEL_CODE:BOOT_KERNEL_ADD
 
 kernel:	db	"KERNEL  BIN"
 k_count: dw	0