Michel,
Yes to both, however when I set radeon.agpmode=1 most of the time the kernel freezes when booting. When I do get past that I get these errors:
rican-linux@Debian-G5:~$ dmesg |grep -e radeon -e drm
[ 0.000000] Kernel command line: root=UUID=aeca9a67-31d7-4c4b-a0f8-4db328b33305 radeon.agpmode=1[ 10.432049] [drm] Initialized drm 1.1.0 20060810
[ 11.291427] [drm] radeon kernel modesetting enabled.
[ 11.302838] fb: switching to radeondrmfb from OFfb ATY,Simone
[ 11.317952] fb: switching to radeondrmfb from OFfb ATY,Simone
[ 11.321318] radeon 0000:f0:10.0: enabling device (0006 -> 0007)
[ 11.321741] [drm] initializing kernel modesetting (RV350 0x1002:0x4150 0x1002:0x4150 0x00).
[ 11.321770] [drm] register mmio base: 0xA0000000
[ 11.321776] [drm] register mmio size: 65536
[ 11.321820] radeon 0000:f0:10.0: Invalid PCI ROM header signature: expecting 0xaa55, got 0x0000
[ 11.415530] [drm] Not an x86 BIOS ROM, not using.
[ 11.415573] [drm] Using device-tree clock info
[ 11.415769] [drm:.radeon_agp_init [radeon]] *ERROR* Illegal AGP Mode: 1 (valid 4, 8), leaving at 8[ 11.415818] radeon 0000:f0:10.0: putting AGP V3 device into 8x mode
[ 11.415925] radeon 0000:f0:10.0: GTT: 256M 0x00000000 - 0x0FFFFFFF
[ 11.415933] [drm] Generation 2 PCI interface, using max accessible memory
[ 11.415943] radeon 0000:f0:10.0: VRAM: 256M 0x00000000B0000000 - 0x00000000BFFFFFFF (64M used)
[ 11.415987] [drm] Detected VRAM RAM=256M, BAR=256M
[ 11.415993] [drm] RAM width 128bits DDR
[ 11.416229] [drm] radeon: 64M of VRAM memory ready
[ 11.416237] [drm] radeon: 256M of GTT memory ready.
[ 11.416308] [drm] radeon: 1 quad pipes, 1 Z pipes initialized.
[ 11.431606] radeon 0000:f0:10.0: WB disabled
[ 11.431627] radeon 0000:f0:10.0: fence driver on ring 0 use gpu addr 0x0000000000000000 and cpu addr 0xd000000003ee0000
[ 11.431642] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 11.431648] [drm] Driver supports precise vblank timestamp query.
[ 11.431700] [drm] radeon: irq initialized.
[ 11.431743] [drm] Loading R300 Microcode
[ 11.488921] radeon 0000:f0:10.0: firmware: direct-loading firmware radeon/R300_cp.bin
[ 11.489178] [drm] radeon: ring at 0x0000000000010000
[ 11.637210] [drm:.r100_ring_test [radeon]] *ERROR* radeon: ring test failed (scratch(0x15E4)=0xCAFEDEAD)
[ 11.637318] [drm:.r100_cp_init [radeon]] *ERROR* radeon: cp isn't working (-22).
[ 11.637331] radeon 0000:f0:10.0: failed initializing CP (-22).
[ 11.637338] radeon 0000:f0:10.0: Disabling GPU acceleration
[ 11.784325] [drm:.r100_cp_fini [radeon]] *ERROR* Wait for CP idle timeout, shutting down CP.
[ 11.931351] [drm] radeon: cp finalized[ 11.931464] radeon 0000:f0:10.0: (r300_asic_reset:425) RBBM_STATUS=0x80010140
[ 12.431463] radeon 0000:f0:10.0: (r300_asic_reset:444) RBBM_STATUS=0x80010140
[ 12.927471] radeon 0000:f0:10.0: (r300_asic_reset:456) RBBM_STATUS=0x00000140
[ 12.927510] radeon 0000:f0:10.0: GPU reset succeed