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Boot Monitor

This page describes the NetBSD bootloader, as used by MINIX3.

To get a summary of what the it can do, while in it, you can select “Drop to boot prompt” from the menu and type:


Commonly Used MINIX3 Boot Options

A rundown of oft-used MINIX3 boot options:

cttyline=0 Used for serial debugging; parameter selects serial port.
cttybaud= Sets serial baud rate. 115200 is recommended.
bootopts=-s Enables single-user mode.
no_apic= <zero> to turn APIC on, <non-zero> to turn it off. There is also apic_timer_x=<n>. acpi=yes is required with no_apic=0
no_smp= <zero> to turn SMP on, <non-zero> to turn it off.
pci_debug=1 Enable PCI driver debug prints.
rootdevname= E.g. c0d0p0s0; Sets the partition from which to load boot components.
watchdog= <non-zero> to turn on the NMI watchdog (kernel lock up detection; also requires no_apic=0 and acpi=yes).

Some less used options:

acpi=yes Use the ACPI driver.
ahci=yes Use the AHCI driver instead of the “at_wini” IDE driver (experimental!). Many other ahci= options are available to help debugging; see the code.
ata_no_dma=1 Disable DMA.
ata_pci_debug=1 Enable PCI-related debugging info in at_wini driver. Some other ata= options are available to help debugging; see the code.
atapi_dma=1 Enable ATAPI DMA.
bios_wini=yes Use the BIOS driver instead of the “at_wini” IDE driver.
bios_remap_first=1 Force the boot drive to be remapped as d7; this allows a machine booted from an inserted media (like a faked disk image from CD booting or a USB thumb drive) to retain its normal drive assignation.
console=8003 Enable 50 lines for the text-mode console.
debug_fkeys=1 Enable pressing F1..F10 keys to show information about the system on the console.
disable=<daemon> Prevent one daemon (optional service) to start; useful when debugging, or if some piece of hardware has problems; disable=inet will prevent the INET network stack to start; disable=lwip,lance will prevent both the LWIP network stack and the LANCE driver to start.
hz=60 Set the system heart beat.
label=<label> Allows the binding of several configurations in a single image.
memory=<range> Describe the installed memory in the computer; useful to override incorrect or faulty detection or to fake a memory-starved machine.
oxpcie= <hexport> document me!
rootdev=<device> document me! Also bootdev, ramimagedev, and ramsize, described in the monitor(8) manpage.
rs_verbose=1 Enable debugging of Resurrection Server.
skip_boot_config=1 Prevents the service edit operation on the booting processes (??? document me better!)
sticky_alt=1 Changes the behaviour of the Alt key to match Unix practice (Meta key).
verbose=1 Enable debugging while loading and starting kernel; verbose=2 is much more verbose.
vm_sanitychecklevel=<n> Enable debugging of VM Server.

Booatloader commands

Some bootloader commands (to be extended):

menu Shows the Menu.
edit Edit a boot menu option before executing it.
ls Lists the files present on the root device.
boot Boots the kernel.
load_mods Loads specified modules by path; wildcard (“*”) searches in the path are accepted.
multiboot Boots the kernel with loaded modules; boot -s will stop before running optional services.
usersguide/bootmonitor.txt · Last modified: 2015/10/31 15:53 by dcvmoole