Works fine here. You just need to set the drive to AHCI in the BIOS
OpenBSD 5.2-current (GENERIC.MP) #4: Thu Aug 30 18:12:48 MDT 2012
dera...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP
RTC BIOS diagnostic error 3fconfig_unit,memory_size,fixed_disk,invalid_time
real mem = 8464576512 (8072MB)
avail mem = 8216829952 (7836MB)
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 2.6 @ 0xf1d30 (106 entries)
bios0: vendor Dell Inc. version A06 date 07/11/2011
bios0: Dell Inc. Latitude E6420
acpi0 at bios0: rev 2
acpi0: sleep states S0 S3 S4 S5
acpi0: tables DSDT FACP APIC TCPA SSDT MCFG HPET BOOT SSDT SSDT DMAR SLIC
acpi0: wakeup devices UAR1(S3) HDEF(S4) GLAN(S4) PXSX(S4) RP01(S4) PXSX(S4)
RP02(S4) PXSX(S4) RP04(S4) PXSX(S4) RP05(S4) PXSX(S4) RP06(S4) PXSX(S4)
RP07(S4) PXSX(S4) RP08(S4) PEG0(S4) PEGP(S4) PEG1(S4) PEG2(S4) PEG3(S4)
PXSX(S4) RP03(S4) EHC2(S1) EHCI(S1) LID_(S3) PBTN(S3)
acpitimer0 at acpi0: 3579545 Hz, 24 bits
acpimadt0 at acpi0 addr 0xfee0: PC-AT compat
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz, 2494.71 MHz
cpu0:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS
H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,SSE3,PCLMUL,DTES64,MWAIT,DS-CPL,VMX
,SMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,POPCNT,DEADLINE,A
ES,XSAVE,AVX,NXE,LONG,LAHF
cpu0: 256KB 64b/line 8-way L2 cache
cpu0: apic clock running at 99MHz
cpu1 at mainbus0: apid 2 (application processor)
cpu1: Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz, 2494.34 MHz
cpu1:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS
H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,SSE3,PCLMUL,DTES64,MWAIT,DS-CPL,VMX
,SMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,POPCNT,DEADLINE,A
ES,XSAVE,AVX,NXE,LONG,LAHF
cpu1: 256KB 64b/line 8-way L2 cache
cpu2 at mainbus0: apid 1 (application processor)
cpu2: Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz, 2494.34 MHz
cpu2:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS
H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,SSE3,PCLMUL,DTES64,MWAIT,DS-CPL,VMX
,SMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,POPCNT,DEADLINE,A
ES,XSAVE,AVX,NXE,LONG,LAHF
cpu2: 256KB 64b/line 8-way L2 cache
cpu3 at mainbus0: apid 3 (application processor)
cpu3: Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz, 2494.34 MHz
cpu3:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS
H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,SSE3,PCLMUL,DTES64,MWAIT,DS-CPL,VMX
,SMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,POPCNT,DEADLINE,A
ES,XSAVE,AVX,NXE,LONG,LAHF
cpu3: 256KB 64b/line 8-way L2 cache
ioapic0 at mainbus0: apid 2 pa 0xfec0, version 20, 24 pins
acpimcfg0 at acpi0 addr 0xf800, bus 0-63
acpihpet0 at acpi0: 14318179 Hz
acpiprt0 at acpi0: bus 0 (PCI0)
acpiprt1 at acpi0: bus -1 (P0P1)
acpiprt2 at acpi0: bus 1 (RP01)
acpiprt3 at acpi0: bus 2 (RP02)
acpiprt4 at acpi0: bus 9 (RP04)
acpiprt5 at acpi0: bus -1 (RP05)
acpiprt6 at acpi0: bus 10 (RP06)
acpiprt7 at acpi0: bus -1 (RP07)
acpiprt8 at acpi0: bus -1 (RP08)
acpiprt9 at acpi0: bus -1 (PEG0)
acpiprt10 at acpi0: bus -1 (PEG1)
acpiprt11 at acpi0: bus -1 (PEG2)
acpiprt12 at acpi0: bus -1 (PEG3)
acpiprt13 at acpi0: bus 3 (RP03)
acpiec0 at acpi0
acpicpu0 at acpi0: C3, C2, C1, PSS
acpicpu1 at acpi0: C3, C2, C1, PSS
acpicpu2 at acpi0: C3, C2, C1, PSS
acpicpu3 at acpi0: C3, C2, C1, PSS
acpitz0 at acpi0: critical temperature is 107 degC
acpibtn0 at acpi0: LID_
acpibtn1 at acpi0: PBTN
acpibtn2 at acpi0: SBTN
acpiac0 at acpi0: AC unit online
acpibat0 at acpi0: BAT0 model DELL 9KN4418 serial 711 type LION oem SMP
acpibat1 at acpi0: BAT1 not present
acpibat2 at acpi0: BAT2 not present
acpivideo0 at acpi0: VID_
acpivout0 at acpivideo0: LCD_
cpu0: Enhanced SpeedStep 2494 MHz: speeds: 2501, 2500, 2200, 2000, 1800, 1600,
1400, 1200, 1000, 800 MHz
pci0 at mainbus0 bus 0
pchb0 at pci0 dev 0 function 0 Intel Core 2G Host rev 0x09
vga1 at pci0 dev 2 function 0 Intel HD Graphics 3000 rev 0x09
wsdisplay0 at vga1 mux 1: console (80x25, vt100 emulation)
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
intagp0 at vga1
agp0 at intagp0: aperture at 0xd000, size 0x1000
inteldrm0 at vga1: apic 2 int 16
drm0 at inteldrm0
Intel 6 Series MEI rev 0x04 at pci0 dev 22 function 0 not configured
em0 at pci0 dev 25 function 0 Intel 82579LM rev 0x04: msi, address
5c:26:0a:7d:33:b6
ehci0 at pci0 dev 26 function 0 Intel 6 Series USB rev 0x04: apic 2 int 16
usb0 at ehci0: USB revision 2.0
uhub0 at usb0 Intel EHCI root hub rev 2.00/1.00 addr 1
azalia0 at pci0 dev 27 function 0 Intel 6 Series HD Audio rev 0x04: msi
azalia0: codecs: IDT/0x76e7, Intel/0x2805, using IDT/0x76e7
audio0 at azalia0
ppb0 at pci0 dev 28 function 0 Intel 6 Series PCIE rev 0xb4: msi
pci1 at ppb0 bus 1
ppb1 at pci0 dev 28 function 1 Intel 6 Series PCIE rev 0xb4: msi
pci2 at ppb1 bus 2
iwn0 at pci2 dev 0 function 0 Intel Centrino Advanced-N 6205 rev 0x34: msi,
MIMO 2T2R,
