[Nix-dev] xserver ignores custom vesa modes

[Marco Maggesi]

Hi,

I use NixOS as guest os in VirtualBox.
I would like to set up the xserver to match the resolution of the  
physical screen of my laptop: 1440x900.
But all my attempts were unsuccessful so far.

Here is what I tried.

Following the instruction in the virtual box manual, I added a custom  
vesa mode to the virtual machine
with command

  $ VBoxManage setextradata nixbox "CustomVideoMode1" "1440x900x24"

(the virtualbox user manual also recites (sec 9.5):
``
  The VESA mode IDs for custom video modes start at 0x160. In order to  
use the
  above defined custom video mode, the following command line has be  
supplied to Linux:
  vga = 0x200 | 0x160
  vga = 864
``
which is a pretty cryptic explanation for me.)


Then, I modified /etc/nixos/configuration.nix in the guest machine as  
follows:

[...]
    xserver = {
      enable = true;
      videoDriver = "vesa";
      sessionType = "";
      windowManager = "none";
      sessionStarter = "";
      resolutions = [ { x=1440; y=900; } { x=1152; y=864; } ];
    };
[...]

With the above setup the server ignores the resolution 1440x900 and  
starts with resolution 1152x864.

The generated xserver.conf looks good.
The log file /var/log/X.0.log (see below an extract) reveals that the  
custom vesa
mode 1440x900 is recognized but is ignored anyway ("no mode of this  
name").

I tried some clever google search.
But they were not clever enough :(

Any idea?
Thanks,
M.

----

$ cat /var/log/X.0.log

[...]

(II) VESA(0): initializing int10
(II) VESA(0): Primary V_BIOS segment is: 0xc000
(II) VESA(0): VESA BIOS detected
(II) VESA(0): VbeVersion is 512, OemStringPtr is 0xc0007c3c,
	OemVendorNamePtr is 0xc0007c6b, OemProductNamePtr is 0xc0007c82,
	OemProductRevPtr is 0xc0007c99
(II) VESA(0): VESA VBE Version 2.0
(II) VESA(0): VESA VBE Total Mem: 8192 kB
(II) VESA(0): VESA VBE OEM: VirtualBox VBE BIOS http://www.virtualbox.org/
(II) VESA(0): VESA VBE OEM Software Rev: 0.2
(II) VESA(0): VESA VBE OEM Vendor: Sun Microsystems, Inc.
(II) VESA(0): VESA VBE OEM Product: VirtualBox VBE Adapter
(II) VESA(0): VESA VBE OEM Product Rev: Sun xVM VirtualBox Version 2.1.2
(**) VESA(0): Depth 24, (--) framebuffer bpp 24
(==) VESA(0): RGB weight 888
(==) VESA(0): Default visual is TrueColor
(==) VESA(0): Using gamma correction (1.0, 1.0, 1.0)
(II) Loading sub module "ddc"
(II) LoadModule: "ddc"(II) Module "ddc" already built-in
(II) VESA(0): VESA VBE DDC not supported
(II) VESA(0): Searching for matching VESA mode(s):

[...]

*Mode: 160 (1440x900)
	ModeAttributes: 0x9b
	WinAAttributes: 0x7
	WinBAttributes: 0x0
	WinGranularity: 64
	WinSize: 64
	WinASegment: 0xa000
	WinBSegment: 0x0
	WinFuncPtr: 0xc0007f77
	BytesPerScanline: 4320
	XResolution: 1440
	YResolution: 900
	XCharSize: 8
	YCharSize: 16
	NumberOfPlanes: 1
	BitsPerPixel: 24
	NumberOfBanks: 1
	MemoryModel: 6
	BankSize: 0
	NumberOfImages: 2
	RedMaskSize: 8
	RedFieldPosition: 16
	GreenMaskSize: 8
	GreenFieldPosition: 8
	BlueMaskSize: 8
	BlueFieldPosition: 0
	RsvdMaskSize: 0
	RsvdFieldPosition: 0
	DirectColorModeInfo: 0
	PhysBasePtr: 0xe0000000

(II) VESA(0): Total Memory: 128 64KB banks (8192kB)
(II) VESA(0): Monitor[0]: Using default hsync range of 31.50-37.90 kHz
(II) VESA(0): Monitor[0]: Using default vrefresh range of 50.00-70.00 Hz
(II) VESA(0): Not using mode "1440x900" (no mode of this name)
(II) VESA(0): Not using built-in mode "1280x1024" (width too large for  
virtual size)
(--) VESA(0): Virtual size is 1152x864 (pitch 1152)
(**) VESA(0): *Built-in mode "1152x864"