Changeset 51059 in vbox for trunk/src/VBox/Devices/PC

Timestamp:

Apr 11, 2014 9:38:17 PM (11 years ago)

Author:

vboxsync

Message:

BIOS: Force hard reset if user entered POST but did not indicate warm boot.

File:

• trunk/src/VBox/Devices/PC/BIOS/orgs.asm (modified) (7 diffs)

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

@@ -198 +198 @@
 
 ;;
-;; Start of fixed code - eoi_jmp_post is kept here to allow short jumps.
+;; Start of fixed code - eoi_jmp_post is kept near here to allow short jumps.
 ;;
                 BIOSORG 0E030h
-eoi_jmp_post:
-                call    eoi_both_pics
-                xor     ax, ax
-                mov     ds, ax
-                jmp     dword ptr ds:[0467h]
-
-eoi_both_pics:
                 mov     al, PIC_CMD_EOI
                 out     PIC_SLAVE, al
@@ -228 +221 @@
 set_int_vects   endp
 
+eoi_jmp_post:
+                call    eoi_both_pics
+                xor     ax, ax
+                mov     ds, ax
+                jmp     dword ptr ds:[0467h]
+
+eoi_both_pics:
 ;; --------------------------------------------------------
 ;; POST entry point
@@ -243 +243 @@
                 ;; Reset processor to get out of protected mode. Use system
                 ;; port instead of KBC.
-                ;; NB: We only need bit 0 to be set in AL, which we just
-                ;; determined to be the case.
+reset_sys:
+                mov     al, 1
                 out     92h, al
                 jmp     $               ; not strictly necessary in a VM
@@ -250 +250 @@
                 
 in_real_mode:
-                ;; TODO: Check KBC system flag first
-
                 ;; read the CMOS shutdown status
                 mov     al, 0Fh
@@ -260 +258 @@
                 xchg    ah, al
 
+                ;; Check KBC self-test/shutdown flag. If it is set, we need
+                ;; to check for a reboot attempt.
+                in      al, 64h
+                test    al, 4           ; clear flag indicates cold boot
+                jz      cont_post
+
+                ;; Warm boot, check the shutdown byte.
+                mov     al, ah
+                or      al, al
+                jnz     cont_post
+
+                ;; Warm boot but shutdown byte is zero. This is either a warm
+                ;; boot request or an attempt to reset the system via triple
+                ;; faulting the CPU or similar. Check reboot flag.
+                ;; NB: At this point, registers need not be preserved.
+                push    40h
+                pop     ds
+                cmp     word ptr ds:[72h], 1234h
+                jnz     reset_sys       ; trigger system reset
+
+cont_post:
                 ;; reset the shutdown status in CMOS
                 mov     al, 0Fh
@@ -491 +510 @@
                 call    rtc_post
 
-                ;; PS/2 mouse setup
-                SET_INT_VECTOR 74h, BIOSSEG, int74_handler
-
-                ;; IRQ 13h (FPU exception) setup
-                SET_INT_VECTOR 75h, BIOSSEG, int75_handler
-
-                call    init_pic
-
                 jmp     norm_post_cont
 
@@ -544 +555 @@
 
 norm_post_cont:
+                ;; PS/2 mouse setup
+                SET_INT_VECTOR 74h, BIOSSEG, int74_handler
+
+                ;; IRQ 13h (FPU exception) setup
+                SET_INT_VECTOR 75h, BIOSSEG, int75_handler
+
+                call    init_pic
+
                 C_SETUP
                 ;; ATA/ATAPI driver setup