[Xen-devel] [PATCH] x86: retrieve VBE EDID/DDC info independent of used video mode

["Jan Beulich" <jbeulich@xxxxxxxxxx>]

The code to retrieve this information was protected by a check of a
variable (vbe_version) that would get initialized only when a VESA mode
was selected on the command line.

Since the problem was inherited from Linux, a similar patch went out to
lkml a few minutes ago.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

Index: 2007-06-18/xen/arch/x86/boot/video.S
===================================================================
--- 2007-06-18.orig/xen/arch/x86/boot/video.S   2007-06-15 14:05:46.000000000 
+0200
+++ 2007-06-18/xen/arch/x86/boot/video.S        2007-06-19 17:47:57.000000000 
+0200
@@ -428,16 +428,12 @@ setmenu:
         jmp     mode_set
 
 check_vesa:
-#ifdef CONFIG_FIRMWARE_EDID
         leaw    modelist+1024, %di
         movw    $0x4f00, %ax
         int     $0x10
         cmpw    $0x004f, %ax
         jnz     setbad
 
-        movw    4(%di), %ax
-        movw    %ax, bootsym(vbe_version)
-#endif
         leaw    modelist+1024, %di
         subb    $VIDEO_FIRST_VESA>>8, %bh
         movw    %bx, %cx                # Get mode information structure
@@ -891,8 +887,13 @@ store_edid:
         cmpb    $1, bootsym(opt_edid)   # EDID disabled on cmdline (edid=no)?
         je      .Lno_edid
 
-        cmpw    $0x0200, bootsym(vbe_version)  # only do EDID on >= VBE2.0
-        jl      .Lno_edid
+        leaw    modelist, %di
+        movw    $0x4f00, %ax
+        int     $0x10
+        cmpw    $0x004f, %ax
+        jne     .Lno_edid
+        cmpw    $0x0200, 4(%di)         # only do EDID on >= VBE2.0
+        jb      .Lno_edid
 
         xorw    %di, %di                # Report Capability
         pushw   %di
@@ -901,6 +902,8 @@ store_edid:
         xorw    %bx, %bx
         xorw    %cx, %cx
         int     $0x10
+        pushw   %ds
+        popw    %es
         cmpw    $0x004f, %ax            # Call failed?
         jne     .Lno_edid
 
@@ -920,8 +923,6 @@ store_edid:
         movw    $0x01, %bx
         movw    $0x00, %cx
         movw    $0x00, %dx
-        pushw   %ds
-        popw    %es
         movw    $bootsym(boot_edid_info), %di
         int     $0x10
 
@@ -940,7 +941,6 @@ edit_buf:       .space  6       # Line e
 card_name:      .word   0       # Pointer to adapter name
 graphic_mode:   .byte   0       # Graphic mode with a linear frame buffer
 dac_size:       .byte   6       # DAC bit depth
-vbe_version:    .word   0       # VBE bios version
 
 # Status messages
 keymsg:         .ascii  "Press <RETURN> to see video modes available,"




_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel