working on bootloader. we will need stage 2...

4 files changed, 111 insertions, 36 deletions

diff --git a/boot/disk_load_16.asm b/boot/disk_load_16.asm
index 2fa88ee..eae15a0 100644
--- a/boot/disk_load_16.asm
+++ b/boot/disk_load_16.asm
@@ -9,6 +9,21 @@
 
 DISK_LOAD:
     db "D",0
+DISK_LOAD_ERROR
+    db "E",0
+Head:
+    db 0
+Track:
+    db 0
+Sector:
+    db 1
+LBA:
+    dw 0 ;; starts at zero!
+Sectors:
+    dw 80
+Heads:
+    dw 2
+
 
 ;disk_load routune (load dh sectors from drive dl to es:bx)
 ;lba mode has 52 sectors hardcoded!
@@ -16,47 +31,113 @@ disk_load_16:
 
     pusha
     
+;;;    ; check if LBA is supported
+;;;    pusha
+;;;    mov    ah,0x41
+;;;    mov    bx,0x55aa
+;;;    int    0x13                                                    
+;;;    jnc disk_load_lba
+;;;    popa
 
-    ; check if LBA is supported
-    pusha
-    mov    ah,0x41
-    mov    bx,0x55aa
-    int    0x13                                                    
-    jnc disk_load_lba
-    popa
+    disk_load_next:
+
+    call ESBX
 
     ; load using CHS 
+;;    mov al,80		;read dh sectors (amount)
+;;    mov cx,[LBA]
+;;    cmp cx,0
+;;    jne disk_read_normal
+;;    mov al,79		;read dh sectors (amount)
+;;    disk_read_normal
+
+    mov al,1
+
+    mov cl,[Sector]	;sector
+    mov ch,[Track]	;cyl
+
+    mov dl,[BOOT_DRIVE]
+    mov dh,[Head]	;head
+
     mov ah,0x02		;BIOS read sector func
-    mov al,dh		;read dh sectors (amount)
-    mov ch,0x00		;cyl 0
-    mov dh,0x00		;head 0
-    mov cl,0x02		;start at sector 2
-;
     int 0x13		;bios interrupt
 
-    mov bx, DISK_LOAD
+    jnc disk_read_ok  ;ready becaue of error :(
+
+    mov bx, DISK_LOAD_ERROR
     call print_string
 
-    popa
-    ret
-    
-    ; load using LBA
+    jmp $
 
-disk_load_lba:
+    disk_read_ok:
 
-    popa
+    mov ax,[LBA]
+
+    cmp ax,880
+    je disk_load_ready
 
-    xor ah,ah
-    mov ah,0x42
-    lea si,[lba_adr]        
-    int 0x13  
-    jc skip_print
     mov bx, DISK_LOAD
     call print_string
-    skip_print:
+
+    add ax,1	;conver LBA to CHS
+    mov [LBA],ax
+
+    call LBACHS
+
+    jmp disk_load_next
+
+    disk_load_ready:
+
+    jmp $
 
     popa
     ret
+   
+ESBX:
+
+    xor dx,dx
+    xor dx,dx
+    mov ax,[LBA]
+    mov bx,0x200
+    mul bx
+    mov bx,ax
+    add dx,1
+    shl dx,12
+    mov es,dx
+
+ret
+
+
+    ; load using LBA
+
+;;;disk_load_lba:
+;;;
+;;;    popa
+;;;
+;;;    xor ah,ah
+;;;    mov ah,0x42
+;;;    lea si,[lba_adr]        
+;;;    int 0x13  
+;;;    jc skip_print
+;;;    mov bx, DISK_LOAD
+;;;    call print_string
+;;;    skip_print:
+;;;
+;;;    popa
+;;;    ret
+;;;
+LBACHS:
+          xor     dx, dx                              ; prepare dx:ax for operation
+          div     WORD [Sectors]           ; divide by sectors per track
+          inc     dl                                  ; add 1 (obsolute sector formula)
+          mov     BYTE [Sector], dl
+ 
+          xor     dx, dx                              ; prepare dx:ax for operation
+          div     WORD [Heads]          ; mod by number of heads (Absolue head formula)
+          mov     BYTE [Head], dl             ; everything else was already done from the first formula
+ 
+          mov     BYTE [Track], al            ; not much else to do :)
+          ret
 
 lba_adr:
 
diff --git a/boot/mbr.asm b/boot/mbr.asm
index 4513100..a854615 100644
--- a/boot/mbr.asm
+++ b/boot/mbr.asm
@@ -111,14 +111,8 @@ boot_16:
 ;
 ;    ;remember BOOT_DRIVE (as was set by BIOS)
     mov [BOOT_DRIVE],dl	
-;
-;    ;Load the KERNEL (sectors starting at sector 2)
-    mov ax,KERNEL_SECTOR
-    mov es,ax
-    mov bx,KERNEL_OFFSET
 
-    mov dh, 53 ; for lba mode this is hardcoded anyway
-    mov dl, [BOOT_DRIVE]
+;   ;Load the IMAGE
     call disk_load_16
     
 ;
@@ -139,7 +133,7 @@ boot_16:
 ;    je a20check ;hang if a20 is disabled!
 
 ;    ;VESA:  also setup vesa stuff before entering 32 bit protected mode
-    call VesaSetup
+;   call VesaSetup
 ;
 ;    ;finally lets enter Protected mode!!!
     call switch_to_pm
@@ -175,7 +169,7 @@ boot_32_pm:
 
 ;fill partition table (4x16byte) with zeroes. 
 ;(otherwise my Acer Aspire will not boot)
-times 64 db 0x0
+;times 64 db 0x0
 
 ;so we get identified as MBR
 times 510-($-$$) db 0x0
diff --git a/boot/vesa_setup_16.asm b/boot/vesa_setup_16.asm
index 96e16e2..f21cbff 100644
--- a/boot/vesa_setup_16.asm
+++ b/boot/vesa_setup_16.asm
@@ -39,7 +39,7 @@ VesaSetup:
     int 0x10
     cmp ax,0x004f
     je vesa_ok3
-    vesa_err3
+    vesa_err3:
     mov bx, VESA_CHECK3
     call print_string
     jmp vesa_err3
diff --git a/data/fill.asm b/data/fill.asm
index 49be4d3..216a328 100644
--- a/data/fill.asm
+++ b/data/fill.asm
@@ -7,4 +7,4 @@
 ;
 ;
 
-times  1474560	db 0x00
+times  1474560	db 0x69