WIPHEADmaster

1 files changed, 51 insertions, 6 deletions

diff --git a/src/boot.s b/src/boot.s
index 28da384..3e86770 100644
--- a/src/boot.s
+++ b/src/boot.s
@@ -1,15 +1,59 @@
-    mov ax, 0x7c0
+    ; TODO: Check which MBR partition is bootable and it's type
+
+    cld ; clear the direction flag so that sto* and lod* increment di
+
+    ; Test for EDD
+    mov ah, 0x41
+    mov bx, 0x55AA ; boot signature word, why ?
+    mov dl, 0x80 ; drive index (HDD 1)
+    int 0x13
+    jc exit
+    cmp bx, 0xAA55
+    jne exit
+
+    ; Read sector 1
+        ; fill disk address packet (read 1 sector at offset 1)
+        mov ax, 0
+        mov es, ax
+        mov di, 0x200
+        mov ax, 16      ; size of packet
+        stosb
+        mov ax, 0       ; always 0
+        stosb
+        mov ax, 1       ; number of sectors
+        stosb
+        mov ax, 0       ; always 0
+        stosb
+        mov ax, 0x200   ; offset
+        stosw
+        mov ax, 0x7c0   ; segment
+        stosw
+        mov ax, 0x1     ; lower 4 bytes of LBA
+        stosd
+        mov ax, 0x0     ; upper 2 bytes of LBA
+        stosd
+    mov ax, 0
     mov ds, ax
-    mov ax, 0xb800 ; protected mode video memory segment (addr / 16)
-    mov es, ax
-    mov si, msg
+    mov si, 0x200
+    mov ah, 0x42
+    mov dl, 0x80 ; drive index (HDD 1)
+    int 0x13
+
+main_continuation:
 
-    cld
+    mov ax, 0xb800 ; protected mode video memory segment (seg / 16 + off)
+    mov es, ax
+    mov ax, 0x7c0
+    mov ds, ax
+    mov si, 0x22b
+    ; mov si, msg
 
     call print
 
     cli
 
+    jmp hang
+
 ; print using BIOS functions
 ; print_loop:
 ;     lodsb                   ; load byte from DS:SI into al
@@ -34,7 +78,6 @@ print:
     mov dx, 160
     mul dx
 
-    xor di, di
     mov di, bx
     add di, ax
 
@@ -79,3 +122,5 @@ hang:
 
     ; db 'TEST'
     ; times 0x800000 - ($-$$) db 0
+
+exit: