* grub-core/boot/i386/qemu/boot.S: Ensure that A20 is enabled.

	Conceptually based on change in branch "vbe-on-coreboot".

diff --git a/ChangeLog b/ChangeLog
index 65b82c6144e2a0b94712a52f9c818ca57924bd82..7188f4e00b008851e57df5e11d78cb79c13d57c4 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-10-25  Vladimir Serbinenko  <phcoder@gmail.com>
+
+       * grub-core/boot/i386/qemu/boot.S: Ensure that A20 is enabled.
+       Conceptually based on change in branch "vbe-on-coreboot".
+
 2013-10-24  Robert Millan  <rmh@gnu.org>
 
        * grub-core/video/i386/pc/vbe.c (grub_video_vbe_setup): Replace

diff --git a/grub-core/boot/i386/qemu/boot.S b/grub-core/boot/i386/qemu/boot.S
index 97aeab9e6531309bcd27f9ac82e3ddde70c33932..ebbfe8828fd613a3dfbe85ab592682652c35fb97 100644 (file)
--- a/grub-core/boot/i386/qemu/boot.S
+++ b/grub-core/boot/i386/qemu/boot.S
@@ -51,6 +51,13 @@ VARIABLE(grub_core_entry_addr)
        pushl   $1f
        DATA32  jmp real_to_prot
        .code32
+       /* Ensure A20 is enabled. We're in qemu, so control port A works
+          and there is no need to wait since there is no real logic, it's
+          all emulated.  */
+       inb     $0x92
+       andb    $(~0x03), %al
+       orb     $0x02, %al
+       outb    $0x92
 1:
        movl    grub_core_entry_addr, %edx
        jmp     *%edx