-v = verbose mode. Basically tells you wants happening during boot up.

-x
= Safe mode. Basically boots your system with the bare minimum kexts.

-s
= Single user mode. Command line only mode. Allows you to run commands as root to fix system.

-f
= Tells the machine to reload all kext and dump the boot configuration cache, (kext cache found in: /System/Library/Extensions.mkext, you can delete it manually and the system will recreate it).

"Graphics Mode"=
Tells the system what resolution width, height, color depth & refresh rate to boot the OS with.

Ex: "Graphics Mode"="1024x768x32" WIDTHxHEIGHTxDEPTH


For VESA 3.0 graphics, you may append a refresh rate after an "@" character


Ex: "Graphics Mode"="640x480x32@60" WIDTHxHEIGHTxDEPTH@REFRESHRATE


rd=
This parameter state what is the boot disk to use (instead of using the boot menu appearing before the prompt) you state the drive and partition in here: diskXsY where X stands for the disk number (first disk, usually primary master in IDE or SATA) 0 second disk is 1 etc.) and Y stands for the partition on that disk starting with 1 as the first partition.

Ex: rd=disk0s1 If you have one disk and one partition the parameter will look like this.


You can also use rd=*<IODeviceTree path> for booting from a PCI RAID card for example. Ex: of this would be rd=*/PCI0@0/CHN0@0/@0:1


Platform=
this parameter sets the platform to use at this boot time.

Examples of this flag are:


platform=ACPI (ACPI support)

platform=X86PC (non ACPI support)
platform=ACPI|86PC (try to support ACPI if fails do not support it)

?memory
= this info screen display information about the memory on the machine

?video
= this info screen display information about the video card supported graphic modes

ACPI Flags


acpi=off
= Don't enable ACPI

acpi=ht
= Use ACPI boot table parsing, but don't enable ACPI interpreter

acpi=force
= Force ACPI on (currently not needed)

acpi=strict
= Disable out of spec ACPI workarounds.

acpi_sci=
{edge,level,high,low} Set up ACPI SCI interrupt. EX: acpi_sci=edge

acpi=noirq
= Don't route interrupts