When I disable USB legacy support in my motherboard's BIOS, I cannot use
the keyboard in the bootloader, which is quite frustrating. When I
enable USB legacy support, my machine often freezes while booting.

Below is the output of dmesg(1):


| Copyright (c) 1992-2006 The FreeBSD Project.
| Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
| 	The Regents of the University of California. All rights reserved.
| FreeBSD 6.1-STABLE #0: Sat Jun 24 18:16:39 CEST 2006
|     root@zonk.fxq.nl:/usr/obj/usr/src/sys/ZONK
| Timecounter "i8254" frequency 1193182 Hz quality 0
| CPU: Intel(R) Pentium(R) 4 CPU 2.26GHz (2266.76-MHz 686-class CPU)
|   Origin = "GenuineIntel"  Id = 0xf24  Stepping = 4
|   Features=0x3febfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM>
| real memory  = 536805376 (511 MB)
| avail memory = 511766528 (488 MB)
| ACPI APIC Table: <AMIINT INTEL845>
| ioapic0 <Version 2.0> irqs 0-23 on motherboard
| acpi0: <AMIINT INTEL845> on motherboard
| acpi0: Power Button (fixed)
| Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
| acpi_timer0: <24-bit timer at 3.579545MHz> port 0x808-0x80b on acpi0
| cpu0: <ACPI CPU> on acpi0
| acpi_throttle0: <ACPI CPU Throttling> on cpu0
| acpi_button0: <Power Button> on acpi0
| pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0
| pci0: <ACPI PCI bus> on pcib0
| agp0: <Intel 82845 host to AGP bridge> mem 0xe0000000-0xe3ffffff at device 0.0 on pci0
| pcib1: <PCI-PCI bridge> at device 1.0 on pci0
| pci1: <PCI bus> on pcib1
| nvidia0: <GeForce FX 5200> mem 0xde000000-0xdeffffff,0xd0000000-0xd7ffffff irq 16 at device 0.0 on pci1
| nvidia0: [GIANT-LOCKED]
| uhci0: <Intel 82801DB (ICH4) USB controller USB-A> port 0xd400-0xd41f irq 16 at device 29.0 on pci0
| uhci0: [GIANT-LOCKED]
| usb0: <Intel 82801DB (ICH4) USB controller USB-A> on uhci0
| usb0: USB revision 1.0
| uhub0: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
| uhub0: 2 ports with 2 removable, self powered
| uhci1: <Intel 82801DB (ICH4) USB controller USB-B> port 0xd800-0xd81f irq 19 at device 29.1 on pci0
| uhci1: [GIANT-LOCKED]
| usb1: <Intel 82801DB (ICH4) USB controller USB-B> on uhci1
| usb1: USB revision 1.0
| uhub1: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
| uhub1: 2 ports with 2 removable, self powered
| uhci2: <Intel 82801DB (ICH4) USB controller USB-C> port 0xdc00-0xdc1f irq 18 at device 29.2 on pci0
| uhci2: [GIANT-LOCKED]
| usb2: <Intel 82801DB (ICH4) USB controller USB-C> on uhci2
| usb2: USB revision 1.0
| uhub2: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
| uhub2: 2 ports with 2 removable, self powered
| ehci0: <Intel 82801DB/L/M (ICH4) USB 2.0 controller> mem 0xdffffc00-0xdfffffff irq 23 at device 29.7 on pci0
| ehci0: [GIANT-LOCKED]
| usb3: waiting for BIOS to give up control
| usb3: EHCI version 1.0
| usb3: companion controllers, 2 ports each: usb0 usb1 usb2
| usb3: <Intel 82801DB/L/M (ICH4) USB 2.0 controller> on ehci0
| usb3: USB revision 2.0
| uhub3: Intel EHCI root hub, class 9/0, rev 2.00/1.00, addr 1
| uhub3: 6 ports with 6 removable, self powered
| pcib2: <ACPI PCI-PCI bridge> at device 30.0 on pci0
| pci3: <ACPI PCI bus> on pcib2
| xl0: <3Com 3c905C-TX Fast Etherlink XL> port 0xc800-0xc87f mem 0xdfefff80-0xdfefffff irq 16 at device 4.0 on pci3
| miibus0: <MII bus> on xl0
| ukphy0: <Generic IEEE 802.3u media interface> on miibus0
| ukphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
| xl0: Ethernet address: 00:0a:5e:42:5a:e4
| pcm0: <Creative EMU10K1> port 0xc400-0xc41f irq 17 at device 5.0 on pci3
| pcm0: <TriTech TR28602 AC97 Codec>
| isab0: <PCI-ISA bridge> at device 31.0 on pci0
| isa0: <ISA bus> on isab0
| atapci0: <Intel ICH4 UDMA100 controller> port 0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0xfc00-0xfc0f at device 31.1 on pci0
| ata0: <ATA channel 0> on atapci0
| ata1: <ATA channel 1> on atapci0
| pci0: <serial bus, SMBus> at device 31.3 (no driver attached)
| acpi_button1: <Sleep Button> on acpi0
| sc0: <System console> at flags 0x100 on isa0
| sc0: VGA <16 virtual consoles, flags=0x300>
| vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
%%%
| uhub4: Mitsumi Electric Hub in Apple Extended USB Keyboard, class 9/0, rev 1.10/4.10, addr 2
| uhub4: 3 ports with 2 removable, bus powered
| ukbd0: Mitsumi Electric Apple Extended USB Keyboard, rev 1.10/4.10, addr 3, iclass 3/1
| uhid0: Mitsumi Electric Apple Extended USB Keyboard, rev 1.10/4.10, addr 3, iclass 3/1
| uhub5: vendor 0x0451 General Purpose USB Hub, class 9/0, rev 1.10/1.01, addr 4
| uhub5: 2 ports with 0 removable, bus powered
| ums0: Logitech USB Receiver, rev 1.10/27.04, addr 5, iclass 3/1
| ums0: 8 buttons and Z dir.
| uhid1: Logitech USB Receiver, rev 1.10/27.04, addr 5, iclass 3/1
| Timecounter "TSC" frequency 2266758972 Hz quality 800
| Timecounters tick every 1.000 msec
| ad0: 117800MB <IC35L120AVV207 0 V24OA63A> at ata0-master UDMA100
| ad1: 286103MB <Maxtor 5A300J0 RAMB1TV0> at ata0-slave UDMA100
| acd0: DVDROM <JLMS XJ-HD163D/GHR8> at ata1-master UDMA33
| Trying to mount root from ufs:/dev/ad0s2a

The line marked with %%% is where it sometimes locks up. When I disable
USB legacy support, my machine always boots perfectly.

Fix: 

None.
How-To-Repeat: Go to the BIOS, reset the defaults. FreeBSD boots file. Then go to the
BIOS, enable USB legacy support. FreeBSD will only boot half of the
time, freezing right before attaching the integrated HUB of my Apple
keyboard.