I know bigmem is still in a state of flux and can be enabled by editing
machdep.c and compiling a custom kernel.
I also realise that it may or may not work on OpenBSD AMD64 due to the
absence of an iommu on non VT-d capable Intel systems, aside from the
AGP/PCI-e GART.
What's the best way to test and report this? (GNATS etc?) Is booting up
sufficient, or does it require extensive testing of memory transfers
from each device to above the 4GB line?
FWIW, with the latest kernel UHCI and AHC (specifically an Adaptec 29160
running in a 32 bit PCI slot) don't work on a 975X/Core2Quad system.
Once that's fixed the system boots. (iic also needs to be disabled, but
that's an issue specific to the D975XBX2 motherboard, not to bigmem).
OpenBSD 4.7-current (GENERIC.MP) #0: Thu Apr 15 01:15:12 BST 2010
root@Gladstone.syllopsium.com:/usr/src/sys/arch/amd64/compile/GENERIC.MP
real mem = 8585592832 (8187MB)
avail mem = 8359256064 (7972MB)
User Kernel Config
UKC> disable iic
318 iic* disabled
UKC> disable ahc
61 ahc* disabled
UKC> disable uhci
132 uhci* disabled
133 uhci* disabled
UKC> exit
Continuing...
RTC BIOS diagnostic error 80<clock_battery>
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 2.4 @ 0xe42e0 (39 entries)
bios0: vendor Intel Corp. version "BX97520J.86A.2836.2008.0728.1946"
date 07/28/2008
bios0: Intel Corporation D975XBX2
acpi0 at bios0: rev 0
acpi0: tables DSDT FACP APIC WDDT MCFG ASF! SSDT SSDT SSDT SSDT SSDT
acpi0: wakeup devices SLPB(S4) P32_(S4) UAR1(S4) PEX0(S4) PEX1(S4)
PEX2(S4) PEX3(S4) PEX4(S4) PEX5(S4) UHC1(S3) UHC2(S3) UHC3(S3) UHC4(S3)
EHCI(S3) AC9M(S4) AZAL(S4)
acpitimer0 at acpi0: 3579545 Hz, 24 bits
acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel(R) Core(TM)2 Quad CPU Q6700 @ 2.66GHz, 2667.10 MHz
cpu0: ...
