USBがOpenBSD 5.6インストーラで動作しない

2012 Mac mini（クアッドコアIntel i7）にOpenBSD 5.6 amd64をインストールしようとしていますが、点灯しているキーボードが暗くなり、USBが起動シーケンスの途中で動作を停止します。動作するキーボードがないと、インストーラを続行できません。

このMac miniのOpenBSD 5.5 amd64にインストールして使用すると、キーボードは正常に動作します。他のMac mini（デュアルコアi5）で5.6インストーラを実行しようとすると同じ問題が発生するため、この特定のコンピュータでは奇妙なことではありません。

5.6ディストリビューションでinstall56.iso、install56.fs、cd56.iso、およびbsd.rdを試しました。また、最後の2つのスナップショットでinstall56.isoを試しました。これらのどれも機能しません。

起動時に画面に表示されるテキスト出力、ビデオ、および手書きの内容は次のとおりです（スペルエラーがある可能性があります）。

CD-ROM: 90
Loading /5.6/AMD64/CDBOOT
probing: pc0 mem[568K 63K 511M 510M 1197M 80K 2M 14070M a20=on]
disk: hd0+ hd1+ sd0* cd0
>> OpenBSD/amd64 CDBOOT 3.23
boot>
cannot open cd0a:/etc/random.seed: No such file or directory
booting cd0a:/5.6/amd64/bsd.rd: 3189664+1368975+2401280+0+517104 [72+350160+227754]=0x7b0838
entry point at 0x1000160 [7205c766, 34000004, 24448b12, 6670a304]
kbc: cmd word write error
Copyright (c) 1982, 1986, 1989, 1991, 1993
        The Regents of the University of California.  All rights reserved.
Copyright (c) 1995-2014 OpenBSD. All rights reserved.  http://www.OpenBSD.org

OpenBSD 5.6-current (RAMDISK_CD) #551: Fri Nov 21 10:20:00 MST 2014
    [email protected]:/usr/src/sys/arch/amd64/compile/RAMDISK_CD
RTC BIOS diagnostic error 7f<ROM_cksum,config_unit,memory_size,fixed_disk,invalid_time>
real mem = 17065648128 (16275MB)
avail mem = 16610545664 (15841MB)
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 2.4 @ 0xe0000 (83 entries)
bios0: vendor Apple Inc. version "MM61.88Z.0106.B04.1309191433" date 09/19/2013
bios0: Apple Inc. Macmini6,2
acpi0 at bios0: rev 2
acpi0: sleep states S0 S3 S4 S5
acpi0: tables DSDT FACP HPET APIC SBST ECDT SSDT SSDT SSDT SSDT SSDT SSDT SSDT SSDT SSDT SSDT SSDT SSDT DMAR MCFG
acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel(R) Core(TM) i7-3615QM CPU @ 2.30GHz, 2295.13 MHz
cpu0: FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,MCOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,SSE3,PCLMUL,DTES64,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,POPCNT,DEADLINE,AES,XSAVE,AVX,F16C,RDRAND,NXE,LONG,LAHF,PERF,ITSC,FSGSBASE,SMEP,ERMS
cpu0: 256KB 64b/line 8-way L2 cache

（ここでは途切れがあり、一部の行が欠落している可能性があります。）

ppb2 at pci2 dev 0 function 0 vendor "Intel", unknown product 0x1547 rev 0x03: msi
pci3 at ppb2 bus 6
vendor "Intel", unknown product 0x1547 (class system subclass miscellaneous, rev 0x03) at pci3 dev 0 function 0 not configured
ppb3 at pci2 dev 3 function 0 vendor "Intel", unknown product 0x1547 rev 0x03: msi
pci4 at ppb3 bus 7
ppb4 at pci2 dev 4 function 0 vendor "Intel", unknown product 0x1547 rev 0x03: msi
pci5 at ppb4 bus 56
ppb5 at pci2 dev 5 function 0 vendor "Intel", unknown product 0x1547 rev 0x03: msi
pci6 at ppb5 bus 105
ppb6 at pci2 dev 6 function 0 vendor "Intel", unknown product 0x1547 rev 0x03: msi
pci7 at ppb6 bus 106
vga1 at pci0 dev 2 function 0 "Intel HD Graphics 4000" rev 0x09
wsdisplay0 at vga1 mux 1: console(80x25, vt100 emulation)
"Intel 7 Series xHCI" rev 0x04 at pci0 dev 20 function 0 not configured
"Intel 7 Series MEI" rev 0x04 at pci0 dev 22 function 0 not configured
ehci0 at pci0 dev 26 function 0 "Intel 7 Series USB" rev 0x04: apic 2 int 23
usb0 at ehci0: USB revision 2.0
uhub0 at usb0 "Intel EHIC root hub" rev 2.00/1.00 addr 1
"Intel 7 Series HD Audio" rev 0x04 at pci0 dev 27 function 0 not configured
ppb7 at pci0 dev 28 function 0 "Intel 7 Series PCIE" rev 0xc4: msi
pci8 at ppb7 bus 1
bge0 at pci8 dev 0 function 0 "Broadcom BCM57766" rev 0x01, unknown BCM57766 (0x57766001): msi, address [removed]
bgrphy0 at bge0 phy1: BCM57765 10/100/1000baseT PHY, rev. 1
sdhc0 at pci8 dev 0 function 1 "Broadcom SD Host Controller" rev 0x01: apic 2 int 17
sdhc0 at 0x10: can't map registers
ppb8 at pci0 dev 28 function 1 "Intel 7 Series PCIE" rev 0xc4: msi
pci9 at ppb8 bus 2
vendor "Broadcom", unknown product 0x4331 (class network subsclass miscellaneous, rev 0x02) at pci9 dev 0 function 0 not configured
ppb9 at pci0 dev 28 function 2 "Intel 7 Series PCIE" rev 0xc4: msi
pci10 at ppb9 bus 3
"AT&T/Lucent FW643 1394" rev 0x08 at pci10 dev 0 function 0 not configured
ehci1 at pci0 dev 29 function 0 "Intel 7 Series USB" rev 0x04: apic 2 int 22
usb1 at ehic1: USB revision 2.0
uhub1 at usb1 "Intel EHCI root hub" rev 2.00/1.00 addr 1
"Intel HM77 LPC" rev 0x04 at pci0 dev 31 function 0 not configured
ahci0 at pci0 dev 31 function 2 "Intel 7 Series AHCI" rev 0x04: msi, AHCI 1.3
scsibus0 at ahci0: 32 targets
sd0 at scsibus0 targ 0 lun 0: <ATA, Samsung SSD 850, EXM0> SCSI3 0/direct fixed
naa.50025388a069068d
sd0: 244198MB, 512 bytes/sector, 500118192 sectors, thin
sd1 at scsibus0 targ 1 lun 0: <ATA, Samsung SSD 850, EXM0> SCSI3 0/direct fixed
naa.50025388a0690757
sd1: 244198MB, 512 bytes/sector, 500118192 sectors, thin
"Intel 7 Series SMBus" rev 0x04 at pci0 dev 31 function 3 not configured
isa0 at mainbus0
com0 at isa0 port 0x3f8/8 irq 4: ns8250, no fifo
uhub2 at uhub0 port 1 "vendor 0x8087 product 0x0024" rev 2.00/0.00 addr 2
uhub3 at uhub1 port 1 "vendor 0x8087 product 0x0024" rev 2.00/0.00 addr 2
uhub4 at uhub3 port 8 "vendor 0x0424 product 0x2512" rev 2.00/b.b3 addr 3
uhub5 at uhub4 port 1 "Apple Inc. BRCM20702 Hub" rev 2.00/1.00 addr 4
uhidev0 at uhub5 port 1 configuration 1 interface 0 "vendor 0x05ac product 0x820a" rev 2.00/1.00 addr 5
uhidev0: iclass 3/1, 1 report id
ukbd0 at uhidev0 reportid 1
wskbd0 at ukbd0: console keyboard, using wsdisplay0
uhidev1 at uhub5 port 2 configuration 1 interface 0 "vendor 0x05ac product 0x820b" rev 2.00/1.00 addr 6
uhidev1: iclass 3/1, 2 report ids
uhid at uhidev1 reportid 2 not configured
"Apple Inc. Bluetooth USB Host Controller" rev 2.00/0.79 addr 7 at uhub5 port 3 not configured
uhidev2 at uhub4 port 2 configuration 1 interface 0 "Apple, Inc. IR Receiver" rev 2.00/1.00 addr 8
uhidev2: iclass 3/0, 38 report ids
uhid at uhidev2 reportid 36 not configured
uhid at uhidev2 reportid 37 not configured
uhid at uhidev2 reportid 38 not configured
softraid0 at root
scsibus1 at softraid0: 256 targets
softraid0: trying to bring up sd2 degraded
sd2 at scsibus1 targ 1 lun 0: <OPENBSD, SR RAID 1, 005> SCSI2 0/direct fixed
sd2: 244190MB, 512 bytes/sector, 500102858 sectors
softraid0: roaming device  -> sd1a
root on rd0a swap on rd0b dump on rd0b
erase ^?, werase ^W, kill ^U, intr ^C, status ^T

Welcome to the OpenBSD/amd64 5.6 installation program.
(I)nstall, (U)pgrade, (A)utoinstall or (S)hell? _

起動時にUSBとキーボードが言及されていますが、この時点ではバックライトのキーボードがオンにならず、キーに何も起こりません。使用する他のキーボードはありません。システムのすべてのUSBポートにキーボードを接続してみましたが、役に立ちません。

どのアイデアが問題になる可能性がありますか？ USBキーボードなしでこのシステムを制御する方法はありますか？