NAME
multiboot —
procedure for booting
NetBSD/x86 from a Multiboot-compliant boot loader
DESCRIPTION
Multiboot is a specification that defines a protocol between a boot loader and a
kernel. This protocol allows passing boot information between the two in a
standard way, allowing any Multiboot-compliant boot loader to boot any
Multiboot-compliant kernel. The
NetBSD kernel supports
Multiboot if it was compiled with
options MULTIBOOT (the
default in the ‘GENERIC’ and ‘GENERIC_LAPTOP’
configurations).
Unlike when using the native boot loader, the
NetBSD
kernel recognizes a set of command line arguments if booted through a
Multiboot-compliant boot loader. This is because the Multiboot protocol is not
complete enough to completely configure a
NetBSD
kernel.
The following arguments are recognized:
-
-
- console
- Specifies the console device name. Can be one of
‘com’ or ‘pc’. If the former,
console_addr and console_speed
should be given too.
-
-
- console_addr
- Specifies the serial port address for the console. Defaults
to the value of options CONADDR or ‘0x3f8’
if this was not given.
-
-
- console_speed
- Specifies the serial port speed for the console. Defaults
to the value of options CONSPEED or ‘9600’
if this was not given.
-
-
- root
- Specifies the name of the device to be mounted as the root
partition. It should not be needed because the kernel tries its best to
guess which is the root partition (basing the decision on the device from
which the kernel was loaded from). In cases where the automatic detection
fails, this flag comes useful. Example: ‘root=wd0e’.
Booting with GRUB Legacy
GRUB Legacy is the most popular bootloader that supports Multiboot. You can boot
a
NetBSD kernel (assuming it is compiled with
Multiboot support) with a line similar to the following one:
kernel (fd0)/netbsd.gz -c console=pc root=wd0e
SEE ALSO
options(4)
HISTORY
multiboot support first appeared in
NetBSD
4.0.
AUTHORS
multiboot support was added by
Julio M.
Merino Vidal
<
jmmv@NetBSD.org>.