An intermediate bootloader may pass a boot command line to Memtest86+. The command line may contain one or more options, separated by spaces. Each option consists of an option name, optionally followed by an = sign and one or more parameters, separated by commas. The following options are recognised:

• nosmp
  • disables ACPI table parsing and the use of multiple CPU cores
• nobench
  • disables the integrated memory benchmark
• nobigstatus
  • disables the big PASS/FAIL pop-up status display
• nosm
  • disables SMBUS/SPD parsing, DMI decoding and memory benchmark
• nomch
  • disables memory controller configuration polling
• nopause
  • skips the pause for configuration at startup
• keyboard=type
  • where type is one of
    • legacy
    • usb
    • both
• dark
  • change the default background colour from blue to black
• screen.mode=wxh (EFI framebuffer only)
  • where wxh is the preferred screen resolution (e.g. 1024x768)
• screen.mode=bios (EFI framebuffer only)
  • uses the default screen resolution set by the UEFI BIOS
• screen.rhs-up (graphics mode only)
  • rotates the display clockwise by 90 degrees
• screen.lhs-up (graphics mode only)
  • rotates the display anti-clockwise by 90 degrees
• efidebug
  • displays information about the EFI framebuffer
• usbdebug
  • pauses after probing for USB keyboards
• usbinit=mode
  • where mode is one of
    • 1 = use the two-step init sequence for high speed devices
    • 2 = add a second USB reset in the init sequence
    • 3 = the combination of modes 1 and 2
• console=ttySx,y
  • activate serial/tty console output, where x is one of the following IO port
    • 0 = 0x3F8
    • 1 = 0x2F8
    • 2 = 0x3E8
    • 3 = 0x2E8
  • and y is an optional baud rate to choose from the following list
    • 9600
    • 19200
    • 38400
    • 57600
    • 115200 (default if not specified or invalid)
    • 230400
• console=x,y
  • activate MMIO UART console, where x is the MMIO stride (reg. width)
    • mmio = 8-bit MMIO
    • mmio16 = 16-bit MMIO
    • mmio32 = 32-bit MMIO
  • and y is the MMIO address in hex. with 0x prefix (eg: 0xFEDC9000)

Memtest86+ v6.0 was based on PCMemTest, developed by Martin Whitaker, which was based on Memtest86+ v5.01, developed by Samuel Demeulemeester, which in turn was based on Memtest86, developed by Chris Brady with the resources and assistance listed below:

• The initial versions of the source files bootsect.S, setup.S, head.S and build.c are from the Linux 1.2.1 kernel and have been heavily modified.

• Doug Sisk provided code to support a console connected via a serial port. (not currently used)

• Code to create BadRAM patterns was provided by Rick van Rein.

• The block move test is based on Robert Redelmeier's burnBX test.

• Screen buffer code was provided by Jani Averbach. (not used by Memtest86+ v6.0)

• Eric Biederman provided all of the feature content for version 3.0 plus many bugfixes and significant code cleanup.

• Major enhancements to hardware detection and reporting in version 3.2, 3.3 and 3.4 provided by Samuel Demeulemeester (from Memtest86+ v1.11, v1.60 and v1.70).

In addition, several bug fixes for Memtest86+ were imported from anphsw/memtest86.