Hi guys, I noticed that at bootup my system was complaining about missing radeon/r100_cp.bin file, so I tracked it down to Debian''s wheezy package firmware-linux-nonfree which includes the file. I installed this package and now I''m getting all sorts of errors when I try to start Xen 4.1 (also installed via Debian''s packages): Excerpt from dmesg: [ 6.073729] [drm] radeon kernel modesetting enabled. [ 6.073859] xen: registering gsi 19 triggering 0 polarity 1 [ 6.073879] xen: --> pirq=19 -> irq=19 (gsi=19) [ 6.073894] radeon 0000:0e:0d.0: PCI INT A -> GSI 19 (level, low) -> IRQ 19 [ 6.074188] [drm] initializing kernel modesetting (RV100 0x1002:0x515E 0x1028:0x01B1). [ 6.074226] [drm] register mmio base: 0xFC2D0000 [ 6.074228] [drm] register mmio size: 65536 [ 6.074497] radeon 0000:0e:0d.0: VRAM: 128M 0x00000000D8000000 - 0x00000000DFFFFFFF (16M used) [ 6.074500] radeon 0000:0e:0d.0: GTT: 512M 0x00000000B8000000 - 0x00000000D7FFFFFF [ 6.074507] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010). [ 6.074509] [drm] Driver supports precise vblank timestamp query. [ 6.074552] [drm] radeon: irq initialized. [ 6.074555] [drm] Detected VRAM RAM=128M, BAR=128M [ 6.074557] [drm] RAM width 16bits DDR [ 6.074624] [TTM] Zone kernel: Available graphics memory: 3570914 kiB. [ 6.074626] [TTM] Zone dma32: Available graphics memory: 2097152 kiB. [ 6.074628] [TTM] Initializing pool allocator. [ 6.074651] [drm] radeon: 16M of VRAM memory ready [ 6.074653] [drm] radeon: 512M of GTT memory ready. [ 6.074670] [drm] GART: num cpu pages 131072, num gpu pages 131072 [ 6.096437] [drm] PCIE GART of 512M enabled (table at 0x0000000010A00000). [ 6.096482] radeon 0000:0e:0d.0: WB disabled [ 6.096555] [drm] Loading R100 Microcode [ 6.206973] [drm] radeon: ring at 0x00000000B8001000 [ 6.406309] [drm:r100_ring_test] *ERROR* radeon: ring test failed (scratch(0x15E4)=0xCAFEDEAD) [ 6.406362] [drm:r100_cp_init] *ERROR* radeon: cp isn''t working (-22). [ 6.406408] radeon 0000:0e:0d.0: failed initializing CP (-22). [ 6.406452] radeon 0000:0e:0d.0: Disabling GPU acceleration [ 6.600640] [drm:r100_cp_fini] *ERROR* Wait for CP idle timeout, shutting down CP. [ 6.795013] Failed to wait GUI idle while programming pipes. Bad things might happen. [ 6.795685] [drm] radeon: cp finalized [ 6.796284] [drm] Radeon Display Connectors [ 6.796286] [drm] Connector 0: [ 6.796287] [drm] VGA [ 6.796289] [drm] DDC: 0x60 0x60 0x60 0x60 0x60 0x60 0x60 0x60 [ 6.796291] [drm] Encoders: [ 6.796292] [drm] CRT1: INTERNAL_DAC1 [ 6.867859] [drm] fb mappable at 0xD8040000 [ 6.867861] [drm] vram apper at 0xD8000000 [ 6.867862] [drm] size 1310720 [ 6.867864] [drm] fb depth is 8 [ 6.867865] [drm] pitch is 1280 [ 6.867973] fbcon: radeondrmfb (fb0) is primary device [ 7.034522] Console: switching to colour frame buffer device 160x64 [ 7.047186] fb0: radeondrmfb frame buffer device [ 7.047188] drm: registered panic notifier [ 7.047194] [drm] Initialized radeon 2.12.0 20080528 for 0000:0e:0d.0 on minor 0 Notice the "ring test failed" line. I Googled that and apparently it used to be a problem when trying to run a Radeon graphics card under Xen a long time ago. But I wasn''t able to find any current information about it or how to fix it. This isn''t a deal breaker for me, because my server hardly needs hardware-accelerated graphics. But it would be nice not to be able to fix the problem so that all the hardware is functioning as it should. I suppose if nobody can help me fix this I can always remove the CP microcode and just go back to the complaint about the missing firmware file.