Debugging paging problem on VirtualBox (VT-x)

4 files changed, 27 insertions, 16 deletions

diff --git a/boot/disk_load_16.asm b/boot/disk_load_16.asm
index 4222dd9..e45b89a 100644
--- a/boot/disk_load_16.asm
+++ b/boot/disk_load_16.asm
@@ -7,8 +7,8 @@
 
 [bits 16]
 
-DISK_LOAD_HANG_MSG:
-    db " D",0
+DISK_LOAD:
+    db "D",0
 
 ;disk_load routune (load dh sectors from drive dl to es:bx)
 ;lba mode has 52 sectors hardcoded!
@@ -48,10 +48,8 @@ disk_load_lba:
     lea si,[lba_adr]        
     int 0x13  
     jc skip_print
-
-    mov bx, 0x1000
+    mov bx, DISK_LOAD
     call print_string
-
     skip_print:
 
     popa
diff --git a/boot/mbr.asm b/boot/mbr.asm
index 4ece914..ca851c3 100644
--- a/boot/mbr.asm
+++ b/boot/mbr.asm
@@ -61,7 +61,7 @@ jmp $ ;entry for other processors ;)
 BOOT_DRIVE:
     db 0xff
 STR_VERSION:
-    db "v0.4",0
+    db "v0.5",0
 VESA_CHECK1:
     db "1",0
 VESA_CHECK2:
@@ -145,17 +145,30 @@ boot_32_pm:
 ;    ;http://www.brokenthorn.com/Resources/OSDev9.html
 ;    ;Method 3.1: Enables A20 through keyboard controller
 ;    ;Not all keyboard controllers support this
-;    ;todo: check if this has any effect at all !?!?
-     mov al, 0xdd  ; command 0xdd: enable a20
-;   ;mov al, 0xdf  ; command 0xdf: disable a20
-     out 0x64, al  ; send command to controller
+;    ; does not work in virtual box (with VT-x accerleration?) 
 
-     mov eax,0
-;
+;     mov al, 0xdd  ; command 0xdd: enable a20
+;     mov al, 0xdf  ; command 0xdf: disable a20
+;     out 0x64, al  ; send command to controller
+
+    ;Fast A20 Gate:
+    ;http://wiki.osdev.org/A20_Line
+    
+    in al, 0x92
+    or al, 2
+    out 0x92, al
+
+    ; call kernel!
+    mov eax,0					;booting processor
     call KERNEL_OFFSET			        ;jump into our Kernel!
 ;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;
+
+;fill partition table (4x16byte) with zeroes. 
+;(otherwise my Acer Aspire will not boot)
+times 64 db 0x0
+
 ;so we get identified as MBR
 times 510-($-$$) db 0x0
 ;dw 0x0
diff --git a/boot/pm.asm b/boot/pm.asm
index 8a4f745..73bb9d3 100644
--- a/boot/pm.asm
+++ b/boot/pm.asm
@@ -11,6 +11,7 @@ switch_to_pm:
 
     cli				;switch off interrupts!
     lgdt [gdt_descriptor]	;load descriptor table!
+    lldt [gdt_descriptor]	;load descriptor table! (local)
 
     ;switch on 32-bit protected mode
     mov eax, cr0
diff --git a/boot/vesa_setup_16.asm b/boot/vesa_setup_16.asm
index 7180252..96e16e2 100644
--- a/boot/vesa_setup_16.asm
+++ b/boot/vesa_setup_16.asm
@@ -33,16 +33,15 @@ VesaSetup:
     jmp vesa_err2
     vesa_ok2:
 
-
     ;VESA: finally switch to the mode of choice!
     mov ax,0x4f02   ;vesa function: Set Mode
     mov bx,VESA_MODE_SELECT 
     int 0x10
-    vesa_err3:
-    mov bx, VESA_CHECK3
-    call print_string
     cmp ax,0x004f
     je vesa_ok3
+    vesa_err3
+    mov bx, VESA_CHECK3
+    call print_string
     jmp vesa_err3
     vesa_ok3:
     popa