SDL detects no video memory on AMD Geode LX

Hi list,

I’m trying to port SDL to the AMD Geode LX system. The AMD released a
kernel patch for 2.6.11 and it includes a LX framebuffer and hardware
accleration. (See attach. 1) It uses the system memory as video memory.

Booting with kernel parameter “video=geodefb:vmode=1024x768” works and I
would see the Linux penguin. However, the test programs of libsdl show the

Compiled with SDL 1.2 or newer
Compiled version: 1.2.10
Linked version: 1.2.10

Video driver: fbcon
Current Display: 1024x768, 16 bits per pixel
Red Mask = 0x0000f800
Green Mask = 0x000007e0
Blue Mask = 0x0000001f
Fullscreen video modes:
Hardware surfaces are available ( 0K video memory)

As you can see the video memory is “0”. Any test program related to video
will cause SIGSEGV.

Now if I disable the Geode LX framebuffer and use the VESA framebuffer by
kernel parameter “vga=0x318 video=geodefb:off”, the test programs show this:

Video driver: fbcon
Current Display: 1024x768, 32 bits per pixel
Red Mask = 0x00ff0000
Green Mask = 0x0000ff00
Blue Mask = 0x000000ff
Fullscreen video modes:
Hardware surfaces are available (6144K video memory)

And the test programs work.

I doubt using the system memory as video memory might be the cause of this
program, but I’m not sure it’s the driver or the libsdl that needs to be
fixed and how to fix it.

Any clue will be most appreciated.


Attach. 1

Running Linux on the AMD Geode Architecture=======================================

Configuration Options

The following options enable various Geode and CS5535 features:

CONFIG_MGEODE_GX - Enable GX processor support
CONFIG_MGEODE_LX - Enable LX processor support
CONFIG_BLK_DEV_CS5535 - Enable IDE support for the CS5535 companion chip
CONFIG_HW_RANDOM - Includes support for the LX hardware RNG
CONFIG_FB_GEODE - Enable Geode framebuffer support
CONFIG_FB_GEODE_LX - Enable LX framebuffer support
CONFIG_FB_GEODE_ACCEL - Use acceleration for console drawing
CONFIG_USB_OHCI_HCD - Enable OHCI USB support for the CS5535 companion chip
CONFIG_CIMARRON - (Usually selected automatically) - Support the LX graphics
abstraction layer.

In addition - the following kernel option should be selected as a module
if you are using the Geode ALSA driver modules: