X-Git-Url: http://git.dujemihanovic.xyz/projects?a=blobdiff_plain;f=boot%2Fx86%2Fprotected.s;fp=boot.s;h=d1c7eea34df31ac1a191c26bc2abeb6bb45924d6;hb=63853960825f007827a79f704d291c372c807096;hp=6181a73528610dcaf7c18ea6beb51dbf03865ffe;hpb=0ef05b6c3cc6f4236f2d5ae35d64328d96bcff24;p=nameless-os.git

diff --git a/boot.s b/boot/x86/protected.s
similarity index 64%
rename from boot.s
rename to boot/x86/protected.s
index 6181a73..d1c7eea 100644
--- a/boot.s
+++ b/boot/x86/protected.s
@@ -1,50 +1,6 @@
-	bits 16 ; boot sectors run in real mode
-	org 7C00h ; BIOS loads us at 0x7c00
+; Everything between real mode and the C kernel
 
-KERNEL_OFFSET equ 1000h ; where we will load our kernel
-
-	mov [BOOT_DRIVE], dl ; BIOS puts the number of our boot drive in dl, so we will want to remember this
-
-	mov bp, 9000h ; initialize stack at a spot sufficiently distanced from this code
-	mov sp, bp
-
-	mov di, 0
-
-	xor ax, ax ; clear accumulator
-	int 13h ; BIOS disk services, with a cleared accumulator this will reset the disk controller
-	jc reset_error ; halt if controller reset fails
-
-	mov ah, 2 ; instruct BIOS's interrupt 13h to read sectors
-	mov al, 10 ; load 10 sectors, might be excessive (for now) but it's still good to do so
-	xor ch, ch ; read from 1st cylinder
-	mov cl, 2 ; start reading from 2nd sector, right after the boot sector
-	xor dh, dh ; read from 1st head
-	xor bx, bx ; clear B register
-	mov es, bx ; clear extended segment
-	mov bx, KERNEL_OFFSET ; put the sectors in our desired offset
-	; dl holds the number of the drive to read from, but BIOS already filled this in
-	int 13h ; do the read
-	jc read_error ; halt if read fails
-	cmp al, 10 ; make sure we actually read 10 sectors
-	jl read_error ; halt if we didn't
-	jmp switch_to_pm ; if all is good, begin the switch to 32-bit protected mode
-
-reset_error
-	mov bx, 0B800h
-	mov es, bx
-	mov byte [es:di], '1'
-	jmp halt
-
-read_error
-	mov bx, 0B800h
-	mov es, bx
-	mov byte [es:di], '2'
-	jmp halt
-
-	call switch_to_pm
-
-halt
-	jmp $
+	bits 16
 
 switch_to_pm
 	mov bx, 0B800h
@@ -143,7 +99,3 @@ gdt_desc
 CODE_SEG equ code_seg - gdt_start
 DATA_SEG equ data_seg - gdt_start
 
-BOOT_DRIVE db 0 ; reserve a spot in RAM for our boot drive variable
-
-	times 510-($-$$) db 0
-	dw 0AA55h ; MBR signature