X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=kern%2Fsrc%2Fboot.asm;h=25486e63f4fbdd8a386d8508cbaf4a4b623aafe0;hb=refs%2Fheads%2Fmaster;hp=96506de177878426b08c7da880baebfe4cde1719;hpb=426ed1c5006c82261fee2eea3feafe3282b2b862;p=eightysix

diff --git a/kern/src/boot.asm b/kern/src/boot.asm
index 96506de..25486e6 100644
--- a/kern/src/boot.asm
+++ b/kern/src/boot.asm
@@ -3,18 +3,19 @@
 	bits 16
 	section .bootsect
 
-extern _stage2_start_seg
-extern _stage2_size
+extern _bootsect_start
+extern _kern_start_seg
+extern _kern_size
 
-boot_driveno	equ 7b00h
-num_read_tries	equ 7b06h	; 2 bytes
-sect_pending	equ 7b08h	; 2 bytes
-sect_per_track	equ 7b0ah	; 2 bytes
-cur_head	equ 7b0ch	; 2 bytes - current head
-start_sect	equ 7b0eh	; 2 bytes - start sector in track
-destptr		equ 7b10h	; 2 bytes - destination pointer
-num_heads	equ 7b12h	; 2 bytes - number of heads
-cur_cyl		equ 7b14h	; 2 bytes - current cylinder
+boot_driveno	equ 0500h
+num_read_tries	equ 0506h	; 2 bytes
+sect_pending	equ 0508h	; 2 bytes
+sect_per_track	equ 050ah	; 2 bytes
+cur_head	equ 050ch	; 2 bytes - current head
+start_sect	equ 050eh	; 2 bytes - start sector in track
+destptr		equ 0510h	; 2 bytes - destination pointer
+num_heads	equ 0512h	; 2 bytes - number of heads
+cur_cyl		equ 0514h	; 2 bytes - current cylinder
 
 %macro floppy_motor_off 0
 	pushf
@@ -57,7 +58,7 @@ bios_param_block:
 	db 0		; 25h: winnt flags
 	db 28h		; 26h: signature(?)
 	dd 0		; 27h: volume serial number
-	db "80 SIX BOOT"; 2bh: volume label, 11 bytes
+	db "86BOOT     "; 2bh: volume label, 11 bytes
 	db "FAT12   "	; 36h: filesystem id, 8 bytes
 
 start:
@@ -65,13 +66,18 @@ start:
 	xor ax, ax
 	mov ds, ax
 	mov es, ax
+	mov ss, ax
+	mov [boot_driveno], dl	; save boot drive number
+
+	; relocate boot sector to 600h
+	mov si, 0x7c00
+	mov di, _bootsect_start
+	mov cx, 256
+	rep movsw
+
 	jmp 00:.setcs
 .setcs:
-	; put the stack high
-	mov ax, 0x7f00
-	mov ss, ax
-	xor sp, sp
-	mov [boot_driveno], dl
+	mov sp, _bootsect_start	; temp stack below our relocated address
 
 	; query sectors per track
 	mov ah, 8	; get drive parameters call, dl already has the drive
@@ -92,13 +98,13 @@ start:
 .querydone:
 
 	; load the rest of the code high
-	mov ax, _stage2_size
+	mov ax, _kern_size
 	add ax, 511
 	mov cl, 9
 	shr ax, cl
 	inc ax
 	mov [sect_pending], ax
-	mov ax, _stage2_start_seg
+	mov ax, _kern_start_seg
 	mov es, ax	; destination segment
 	mov word [destptr], 0
 	mov word [start_sect], 1	; start from sector 1 to skip boot sector
@@ -173,7 +179,7 @@ start:
 	jnz .rdloop
 
 	; loaded sucessfully, load segment registers and jump
-.done:	mov ax, _stage2_start_seg
+.done:	mov ax, _kern_start_seg
 	mov ds, ax
 	mov es, ax
 	push ax
@@ -248,7 +254,7 @@ print_hex_digit:
 
 str_rdtrack2	db " from ",0
 str_rdtrack3	db "/",0
-str_load_fail	db "Failed to load 2nd stage!",0
+str_load_fail	db "Failed to load kernel!",0
 str_newline	db 13,10,0
 
 	times 510-($-$$) db 0