Changeset 48446 in vbox

Timestamp:

Sep 12, 2013 11:17:10 AM (11 years ago)

Author:

vboxsync

Message:

BIOS: Reshuffled code, added shutdown code 9 support.

File:

• trunk/src/VBox/Devices/PC/BIOS/orgs.asm (modified) (4 diffs)

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

@@ -250 +250 @@
                 
 in_real_mode:
-                ;; TODO: This looks very iffy - we shouldn't mess with any
-                ;; hardware until after we've established that cold boot
-                ;; needs to be done.
+                ;; TODO: Check KBC system flag first
+
+                ;; read the CMOS shutdown status
+                mov     al, 0Fh
+                out     CMOS_ADDR, al
+                in      al, CMOS_DATA
+
+                ;; save status
+                xchg    ah, al
+
+                ;; reset the shutdown status in CMOS
+                mov     al, 0Fh
+                out     CMOS_ADDR, al
+                mov     al, 0
+                out     CMOS_DATA, al
+
+                ;; pre-check the shutdown status - shutdown codes 9/A leave
+                ;; the hardware alone
+                mov     al, ah
+                cmp     al, 09h
+                jz      check_shutdown
+                cmp     al, 0Ah
+                jz      check_shutdown
                 
-                xor     ax, ax
+                xor     al, al
 
                 ;; reset the DMA controllers
@@ -266 +286 @@
                 out     0D4h, al        ; unmask channel 4
 
-                ;; read the CMOS shutdown status
-                mov     al, 0Fh
-                out     CMOS_ADDR, al
-                in      al, CMOS_DATA
-
-                ;; save status
-                mov     bl, al
-
-                ;; reset the shutdown status in CMOS
-                mov     al, 0Fh
-                out     CMOS_ADDR, al
-                mov     al, 0
-                out     CMOS_DATA, al
-
+check_shutdown:
                 ;; examine the shutdown status code
-                mov     al, bl
+                mov     al, ah
                 cmp     al, 0
                 jz      normal_post
+
                 cmp     al, 0Dh
                 jae     normal_post
                 cmp     al, 9
-                je      normal_post     ;; TODO: really?!
+                jne     check_next_std
+                jmp     return_blkmove
+check_next_std:         
 
                 ;; 05h = EOI + jump through 40:67
@@ -482 +492 @@
                 call    rom_scan
 
-                C_SETUP
-                ;; ATA/ATAPI driver setup
-                call    _ata_init
-                call    _ata_detect
-
-ifdef VBOX_WITH_AHCI
-                ; AHCI driver setup
-                call    _ahci_init
-endif
-
-ifdef VBOX_WITH_SCSI
-                ; SCSI driver setup
-                call    _scsi_init
-endif
-
-                ;; floppy setup
-                call    floppy_post
-
-                ;; hard drive setup
-                call    hard_drive_post
-
-                C_SETUP                 ; in case assembly code changed things
-                call    _print_bios_banner
-
-                ;; El Torito floppy/hard disk emulation
-                call    _cdemu_init
-
-                ; TODO: what's the point of enabling interrupts here??
-                sti                     ; enable interrupts
-                int     19h
-                ;; does not return here
-                sti
-wait_forever:
-                hlt
-                jmp     wait_forever
-                cli
-                hlt
+                jmp     norm_post_cont
 
 
@@ -561 +535 @@
 hard_drive_post endp
 
+
+norm_post_cont:
+                C_SETUP
+                ;; ATA/ATAPI driver setup
+                call    _ata_init
+                call    _ata_detect
+
+ifdef VBOX_WITH_AHCI
+                ; AHCI driver setup
+                call    _ahci_init
+endif
+
+ifdef VBOX_WITH_SCSI
+                ; SCSI driver setup
+                call    _scsi_init
+endif
+
+                ;; floppy setup
+                call    floppy_post
+
+                ;; hard drive setup
+                call    hard_drive_post
+
+                C_SETUP                 ; in case assembly code changed things
+                call    _print_bios_banner
+
+                ;; El Torito floppy/hard disk emulation
+                call    _cdemu_init
+
+                ; TODO: what's the point of enabling interrupts here??
+                sti                     ; enable interrupts
+                int     19h
+                ;; does not return here
+                sti
+wait_forever:
+                hlt
+                jmp     wait_forever
+                cli
+                hlt
+                
+
+;;
+;; Return from block move (shutdown code 09h). Care must be taken to disturb
+;; register and memory state as little as possible.
+;;
+return_blkmove:
+                mov     ax, 40h
+                mov     ds, ax
+                ;; restore user stack
+                mov     ss, ds:[69h]
+                mov     sp, ds:[67h]
+                ;; reset A20 gate
+                in      al, 92h
+                and     al, 0FDh
+                out     92h, al
+                ;; ensure proper real mode IDT
+                lidt    fword ptr cs:_rmode_IDT
+                ;; restore user segments
+                pop     ds
+                pop     es
+                ;; set up BP
+                mov     bp, sp
+                ;; restore status code
+                in      al, 80h
+                mov     [bp+15], al
+                ;; set ZF/CF
+                cmp     ah,al           ; AH is zero here!
+                ;; restore registers and return
+                popa
+                sti
+                retf    2
+                
 
 ;; --------------------------------------------------------