X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=ld45_start_nothing;a=blobdiff_plain;f=src%2Fboot%2Fboot.asm;h=693bba3f7a60472aaa4d7c2827caed8552fff5e4;hp=80a92a9df4a14227b529299a04ba5702be888903;hb=2cef53ae69622dc995fa0f4ac7a6d793684b4403;hpb=6a16a1c526937ee551f968901cb949d55e35ecda

diff --git a/src/boot/boot.asm b/src/boot/boot.asm
index 80a92a9..693bba3 100644
--- a/src/boot/boot.asm
+++ b/src/boot/boot.asm
@@ -1,10 +1,13 @@
 ; vi:filetype=nasm ts=8 sts=8 sw=8:
 	bits 16
-	org 7c00h
+	section .boot
 
-STACKTOP equ 7c00h
+STACKTOP equ 7b00h
+DRIVENO_ADDR equ 7bf0h
 LOADADDR equ 7e00h
 
+	extern _boot2_size
+
 start:
 	cli
 	; setup stack and the rest of the segment registers
@@ -17,15 +20,15 @@ start:
 	mov gs, ax
 
 	; dl: drive number, save it
-	mov [driveno], dl
+	mov [DRIVENO_ADDR], dl
 	call get_drive_chs
 
 	mov si, newline_str
 	call putstr
 
-	; load main program
+	; load the second stage boot loader and jump there
 	mov bx, LOADADDR  ; es:bx <- destination
-	mov cx, BINSIZE
+	mov cx, _boot2_size
 	add cx, 511
 	shr cx, 9	; cx <- binsize in sectors
 	mov [binsize_sect], cx
@@ -56,7 +59,7 @@ start:
 get_drive_chs:
 	push es
 	mov ah, 8
-	mov dl, [driveno]
+	mov dl, [DRIVENO_ADDR]
 	xor di, di
 	int 13h
 	pop es
@@ -115,7 +118,7 @@ read_sector:
 
 	; ah = 2 (read), al = 1 sectors
 	mov ax, 0201h
-	mov byte dl, [driveno]
+	mov byte dl, [DRIVENO_ADDR]
 	int 13h
 	jnc .success
 
@@ -159,14 +162,17 @@ putchar:
 	ret
 
 
+	global sect_per_track
 sect_per_track:	dw 18
+	global num_cylinders
 num_cylinders:	dw 80
+	global num_heads
 num_heads:	dw 2
+	global heads_mask
 heads_mask:	db 1
 
 read_retries: db 0
 
-driveno: db 0
 binsize_sect: dw 0
 
 rderr_str: db 'read error',13,10,0