vserver 1.9.3

[linux-2.6.git] / arch / i386 / boot / video.S

diff --git a/arch/i386/boot/video.S b/arch/i386/boot/video.S
index 7e2c665..a6e043c 100644 (file)
--- a/arch/i386/boot/video.S
+++ b/arch/i386/boot/video.S
@@ -232,6 +232,41 @@ mopar_gr:
        xorl    %eax, %eax
        movw    18(%di), %ax
        movl    %eax, %fs:(PARAM_LFB_SIZE)
+
+# switching the DAC to 8-bit is for <= 8 bpp only
+       movw    %fs:(PARAM_LFB_DEPTH), %ax
+       cmpw    $8, %ax
+       jg      dac_done
+
+# get DAC switching capability
+       xorl    %eax, %eax
+       movb    10(%di), %al
+       testb   $1, %al
+       jz      dac_set
+
+# attempt to switch DAC to 8-bit
+       movw    $0x4f08, %ax
+       movw    $0x0800, %bx
+       int     $0x10
+       cmpw    $0x004f, %ax
+       jne     dac_set
+       movb    %bh, dac_size           # store actual DAC size
+
+dac_set:
+# set color size to DAC size
+       movb    dac_size, %al
+       movb    %al, %fs:(PARAM_LFB_COLORS+0)
+       movb    %al, %fs:(PARAM_LFB_COLORS+2)
+       movb    %al, %fs:(PARAM_LFB_COLORS+4)
+       movb    %al, %fs:(PARAM_LFB_COLORS+6)
+
+# set color offsets to 0
+       movb    $0, %fs:(PARAM_LFB_COLORS+1)
+       movb    $0, %fs:(PARAM_LFB_COLORS+3)
+       movb    $0, %fs:(PARAM_LFB_COLORS+5)
+       movb    $0, %fs:(PARAM_LFB_COLORS+7)
+
+dac_done:
 # get protected mode interface informations
        movw    $0x4f0a, %ax
        xorw    %bx, %bx
@@ -1929,6 +1964,7 @@ scanning: .byte   0       # Performing mode scan
 do_restore:    .byte   0       # Screen contents altered during mode change
 svga_prefix:   .byte   VIDEO_FIRST_BIOS>>8     # Default prefix for BIOS modes
 graphic_mode:  .byte   0       # Graphic mode with a linear frame buffer
+dac_size:      .byte   6       # DAC bit depth
 
 # Status messages
 keymsg:                .ascii  "Press <RETURN> to see video modes available, "