VirtualBox archive

as of 2011 January: Virtualbox runs with PureDarwin nano

the following info is kept here for historical reasons!

(Pure)Darwin 9 guest OS not supported or it doesn't seem to be trivial to make it works.
No problem concerning loading the bootloader.
Latest versions tested:
  • VirtualBox 3.0.2 on Mac OS X
  • VirtualBox 3.0.6 on Windows XP 32 bits

Problem: black screen at kernel loading (just after kexts decompression), framebuffer unsupported?


VirtualBox random settings

Set up "OS Type" variable as a "FreeBSD" machine.
VT-x/AMD-v is a must.
(ACPI must be disabled)
PAE/NX seems to be needed1 and enabled2
(please add more text)

Physical Address Extension (PAE)

"Physical addresses greater than 32 bits are supported:
extended page table entry formats, an extra level in the page translation tables is defined, 2-MByte pages are supported instead of 4 Mbyte pages if PAE bit is 1.
The actual number of address bits beyond 32 is not defined, and is implementation specific." said Intel


Boot arguments

-v is not needed since it is enabled by default.
(please add more text)

dfe bootloader

Note: Pressing ? + Enter doesn't give any output.

?video flag

?video works in booter and returns:

Note: Passing kernel flag "Graphics Mode"="<value>" also seems to work.

?memory flag

A bit obscure...
Please let us know if you know about.

SMBIOS table not found

Then it fails, attempting to find SMBIOS table.

After using booter boot-132_dfe_r146 (instead of dfe_r28 version) from David Elliott, another problematic error is raised about determination of CPU:FSB multiplier (0 is found...).

Pressing 'y' leads irremediably to a (resized) blank screen, full cpu load, and a critical error forcing to poweroff the vm.

See corresponding VirtualBox log of pressing 'y':

00:00:03.572 Display::handleDisplayResize(): uScreenId = 0, pvVRAM=184d9000 w=640 h=480 bpp=32 cbLine=0xA00
00:00:05.906 Guest Log: Key pressed: 0086
00:00:05.942 Display::handleDisplayResize(): uScreenId = 0, pvVRAM=00000000 w=720 h=400 bpp=0 cbLine=0x0
00:00:09.600 Guest Log: Key pressed: 002E

Please, let us know if you have a solution.

Chameleon bootloader and Voodoo kernel

Other attempts have been made, combining xnu-dev kernel (Voodoo BETA 2b ) and chameleon bootloader (v1.0.11).
We can bypass the error above about CPU:FSB multiplier with the boot argument busratio=...

With ACPI enabled in VirtualBox, the vm hangs at "Local APIC version not 0x14 as expected":

Without ACPI, it complains about and irremediably lead to a kernel panic.


Problem: "Unable to find SMBIOS table"
Solution 0: So, need another BIOS (with correct offset)?
Another solution would be to use the host SMBIOS table, or a copy of it.
See for more information.
Solution 1: It's still remain possible to modify and recompile the VirtualBox sources in order to give a correct SMBIOS.
See VirtualBox/src/VBox/Devices/PC/DevPcBios.cpp
Solution 2: use another kernel (xnu-dev) and/or another bootloader (chameleon)

Machine Specific Registers (MSR)About MSR?

"The processor provides a variety of machine specific registers (accessed via the RDMSR and WRMSR instructions) that are used to control and report on processor performance. Virtually all MSRs handle system related functions and are not accessible to an application program. One exception to this rule is the time-stamp counter." said Intel

CPU:FSB multiplier

According to Wikipedia: "The clock multiplier (or CPU multiplier or bus/core ratio) is the ratio of the internal CPU clock rate to the frequency of its external address/data bus, today often termed front side bus(FSB). A system with a CPU multiplier of 10x will have its CPU execute 10 complete cycles for every cycle of its FSB. For example, a system with an FSB running at 133 MHz and a clock multiplier of 10x, the CPU will run at 1.33 GHz."

CPU model seems OK:
00:00:02.889 Full Name:                       Intel(R) Core(TM)2 CPU         T7400  @ 2.16GHz

T7400 specs example

  • FSB: 667 Mhz
  • Multiplier: 13x

Auto resize and blank screen

The highlighted line could explain why suddenly the screen is auto resized, and consequently why the screen goes blank.

00:00:09.666 Guest Log: BIOS: Booting from CD-ROM...
00:00:58.579 Display::handleDisplayResize(): uScreenId = 0, pvVRAM=184d9000 w=1024 h=768 bpp=32 cbLine=0x1000
00:00:58.608 VERR_REM_TOO_MANY_TRAPS -> uTrap=d error=6a next_eip=ffe01890 eip=ffe01890 cr2=ffe01890
00:00:58.608 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
00:00:58.608 !!
00:00:58.608 !!                 Guru Meditation -2304 (VERR_REM_TOO_MANY_TRAPS)
00:00:58.608 !!
00:00:58.608 !!
00:00:58.608 !! {mappings, <NULL>}
00:00:58.608 !!
1Why PAE/NX seems to be needed?

2How to enable PAE/NX?

Via command-line, assuming PureDarwin is the name of your vm:

/Applications/ modifyvm PureDarwin -pae on

Via gui, a simple checkbox in the settings.

Ressources (Allow SMBIOS information to be copied from host) ( / (A fork of the XNU kernel)