Changeset 38833 in vbox for trunk/src/VBox/Devices/PC/BIOS-new

Timestamp:

Sep 22, 2011 5:56:53 PM (13 years ago)

Author:

vboxsync

Message:

Disable the A20 gate at POST.

Location:

trunk/src/VBox/Devices/PC/BIOS-new

Files:

• biosint.h (modified) (1 diff)
• keyboard.c (modified) (1 diff)

trunk/src/VBox/Devices/PC/BIOS-new/biosint.h

@@ -205 +205 @@
 extern  void        show_logo(void);
 extern  void        delay_boot(uint16_t secs);
+extern  bx_bool     set_enable_a20(bx_bool val);
 
 int scsi_read_sectors(uint8_t device_id, uint16_t count, uint32_t lba, void __far *buffer);

trunk/src/VBox/Devices/PC/BIOS-new/keyboard.c

@@ -302 +302 @@
     /* Enable aux interface */
     outb(0x64,0xa8);
+
+    /* While we're here, disable the A20 gate. Required for
+     * compatibility with the IBM PC and DOS.
+     */
+    set_enable_a20(0);
 }