This page describes the NetBSD boot monitor, as used by MINIX 3.
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:
help
A rundown of oft-used boot monitor commands and options:
| ctty 0 | Used for serial debugging; parameter selects serial port. |
| cttybaud= | Sets serial baud rate. 115200 is recommended. |
| menu | Shows the Menu. |
| ls | Lists the files present on the root device. |
| boot | Boots the kernel. |
| bootopts=-s | Enables single-user mode. |
| 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. |
| 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. |
Some obsolete options, carried over from MINIX 2; information about them will be found in old manual pages.
| bus=at or bus=mca | Mainly determine the kind of PIC to use. |
| processor=586 | Force the detection of a given CPU family. |
| video=vga or video=ega | No noticeable effects are expected. |
| XXXETH<n>= <hardware-dependent> and XXXETH<n>_EA= <MAC address> | Allows the setup of non-PnP hardwares, mainly the network cards; all this has been mostly obsoleted by PCI. The actual names of the variables depend on the driver. |