Changeset 41603 in vbox for trunk/src/VBox/Devices/PC

Timestamp:

Jun 6, 2012 7:04:57 PM (13 years ago)

Author:

vboxsync

Message:

BIOS: More compatible IVT initialization.

File:

• trunk/src/VBox/Devices/PC/BIOS-new/orgs.asm (modified) (2 diffs)

trunk/src/VBox/Devices/PC/BIOS-new/orgs.asm

@@ -256 +256 @@
 ;               jmp     normal_post
 
+
+                ;; routine to write the pointer in DX:AX to memory starting
+                ;; at DS:BX (repeat CX times)
+                ;; - modifies BX, CX
+set_int_vects   proc    near
+
+                mov     [bx], ax
+                mov     [bx+2], dx
+                add     bx, 4
+                loop    set_int_vects
+                ret
+
+set_int_vects   endp
+
 normal_post:
                 ;; shutdown code 0: normal startup
@@ -306 +320 @@
                 call    pmode_setup
 
-                ;; set all interrupts to default handler
+                ;; set all interrupts in 00h-5Fh range to default handler
                 xor     bx, bx
                 mov     ds, bx
-                mov     cx, 78h         ; leave the rest as zeros
+                mov     cx, 60h         ; leave the rest as zeros
                 mov     ax, dummy_iret
                 mov     dx, BIOSSEG
-
-post_default_ints:
-                mov     [bx], ax
-                mov     [bx+2], dx
-                add     bx, 4
-                loop    post_default_ints
-
-                ;; set vector 79h to zero
-                ;; this is used by 'guardian angel' protection system
-                ;; TODO: Really? Why?
-
+                call    set_int_vects
+
+                ;; also set 68h-77h to default handler; note that the
+                ;; 60h-67h range must contain zeros for certain programs
+                ;; to function correctly
+                mov     bx, 68h * 4
+                mov     cx, 10h
+                call    set_int_vects
+                
                 ;; base memory in K to 40:13
                 mov     ax, BASE_MEM_IN_K