When installing Gentoo Linux 1.4.rc2 some week ago, I stumbled across a kernel compilation breakage (gentoo-sources): --- START LISTING --- ld -m elf_i386 -T /usr/src/linux-2.4.19-gentoo-r10/arch/i386/vmlinux.lds -e stext arch/i386/kernel/head.o arch/i386/kernel/init_task.o init/main.o init/version.o init/do_mounts.o \ --start-group \ arch/i386/kernel/kernel.o arch/i386/mm/mm.o kernel/kernel.o mm/mm.o fs/fs.o ipc/ipc.o \ drivers/char/char.o drivers/block/block.o drivers/misc/misc.o drivers/net/net.o drivers/media/media.o drivers/char/agp/agp.o drivers/char/drm/drm.o drivers/ide/idedriver.o drivers/scsi/scsidrv.o drivers/cdrom/driver.o drivers/sound/sounddrivers.o drivers/pci/driver.o drivers/pnp/pnp.o drivers/video/video.o drivers/usb/usbdrv.o \ net/network.o \ grsecurity/grsec.o \ crypto/crypto.o \ /usr/src/linux-2.4.19-gentoo-r10/arch/i386/lib/lib.a /usr/src/linux-2.4.19-gentoo-r10/lib/lib.a /usr/src/linux-2.4.19-gentoo-r10/arch/i386/lib/lib.a \ --end-group \ -o vmlinux drivers/char/drm/drm.o(.text+0x5a34): In function `sis_fb_alloc': : undefined reference to `sis_malloc' drivers/char/drm/drm.o(.text+0x5abf): In function `sis_fb_alloc': : undefined reference to `sis_free' drivers/char/drm/drm.o(.text+0x5b09): In function `sis_fb_free': : undefined reference to `sis_free' drivers/char/drm/drm.o(.text+0x5e3d): In function `sis_final_context': : undefined reference to `sis_free' make: *** [vmlinux] Error 1 --- END LISTING --- The problem is related to the compilation of the kernel support for my SiS 651 graphics card. I have selected support for the card to be compiled directly into the kernel through the following two options: o Character Devices --> Generic SiS support (under /dev/agpgart) o Character Devices --> SiS (under DRM 4.1 drivers) The problem could be worked around by adding framebuffer support to the kernel through by enabling the following options: o Console drivers --> Frame-buffer support --> Support for frame buffer o Console drivers --> Frame-buffer support --> SiS acceleration Reading the make listing above, the error seems to come from the SiS DRM module sharing code with the SiS framebuffer driver. I assume that this could be resolved by modifying the appropriate Makefiles to include compilation and linkage of the sis_main.c file. Alternatively there is some compilation flag that hasn't been set properly that cause the method 'sis_fb_alloc' to be compiled. At the very minimum, the help text for the SiS DRM module should mention that framebuffer support for SiS must also be enabled (although that seems like an ad hoc requirement).
Please see bug #23804 and especially http://www.winischhofer.net/sisdri.shtml for some more info on what I assume this problem is. Also please use the xfree-drm package instead of the DRM in the kernel, as it doesn't work with xfree-4.3. Here's a guide on this: http://www.gentoo.org/doc/en/dri-howto.xml. I'll add a warning to the xfree-drm ebuild that sis framebuffer has to be enabled.
Ok, so it seems that the framebuffer driver is required for the SiS DRI driver. Hence the compilation breakage. It would be great if someone would create a build configuration patch to the 2.4.20 kernel (and 2.4.21 now I guess) to fix the help text and add a dependency. The SiS framebuffer support should really be enabled automagically when someone selects the SiS DRI driver.
I'm no expert on kernel configuration, but it looks like options do not generally get enabled automatically. So, I'll have to satisfy with the following small documentation fix instead: Old Documentation/Configure.help: CONFIG_DRM_SIS Choose this option if you have a SIS graphics card. AGP support is required for this driver to work. New Documentation/Configure.help: CONFIG_DRM_SIS Choose this option if you have a SIS graphics card. AGP support is required for this driver to work. Note that support for the SiS framebuffer driver is REQUIRED for this option to work.
Created attachment 14418 [details, diff] doc fix for sis issue Ok - I added this patch to the current pfeifer-sources tree. This should apply to past gentoo-sources still in portage. Nonetheless, this should be an adequate fix. Sample patch command: patch -p1 -s -N -E -d /usr/src/linux/ < 905_sis_doc_fix.diff Thanks, Jay
closing.
