boot
—
system bootstrapping procedures
When the NetBSD kernel is booted normally (using one of
the two methods discussed below), it initializes itself and proceeds to boot
the system. An automatic consistency check of the file systems takes place,
and unless this fails, the system comes up to multi-user operations. The
proper way to shut the system down is with the
shutdown(8) command.
If the system crashes, it will enter the kernel debugger,
ddb(4), if it is configured in
the kernel. If the debugger is not present, or the debugger is exited, the
system will attempt a dump to the configured dump device (which will be
automatically recovered with
savecore(8) during the
next boot cycle). After the dump is complete (successful or not), the system
will attempt a reboot.
When a bootable NetBSD partition is created by means of
atari/installboot(8)
and the boot-preference bit in the NVRAM is either invalid or set to
NetBSD , the Atari BIOS will automatically start the
NetBSD bootloader. By default it will load the kernel
image /netbsd and attempts to boot it into multi-user
mode. This behaviour can be changed by either keeping the
Alternate or the Right-Shift
key pressed during the boot. When the Alternate key is
pressed, the bootstrap is aborted, causing the BIOS to continue scanning the
disks for a bootable partition (this is compatible with AHDI 3.0). Pressing
the Right-Shift key during the boot, causes the boot
loader to enter the interactive mode. In interactive mode, the command line
looks like:
[OS-type] [boot-path]
[boot-options]
Each component of the command can be omitted in which case the
defaults indicated will be used.
- OS-type:
-
- .netbsd (the default)
-
- .linux
-
- .asv
-
- .tos
-
If something other than .netbsd is
specified, control is returned to the BIOS with the boot preference set
to the selected type. Due to limitations of the BIOS however, the search
for bootblocks is continued rather than restarted.
- boot-path
- This gives you the opportunity to boot another kernel, say:
/netbsd.old. The default is
/netbsd
- boot-options
- These options are a subset of the
loadbsd(8) options.
-a
- Boot into multi-user mode (the default)
-b
- Prompt for the root file system device, the system crash dump device,
and the path to
init(8).
-d
- Enter the kernel debugger
-q
- Boot in quiet mode
-v
- Boot in verbose mode
When you want (or have to) start NetBSD from GEM, you
have to use the loadbsd(8)
program that is supplied on the kernel-floppy. The loadbsd command line
specification is:
loadbsd
[-abdhqstvwDV
] [-S
amount] [-T
amount] kernel-path
Description of options:
-a
- Boot automatically into multi-user mode.
-b
- Prompt for the root file system device, the system crash dump device, and
the path to init(8).
-d
- Enter the kernel debugger after booting.
-h
- Print a help screen that tries to explain the same options as mentioned
here.
-o
outputfile
- Write all output to the file outputfile.
-q
- Boot in quiet mode.
-s
- Tell NetBSD only to use ST compatible RAM.
-t
- Test loading of the kernel but don't start
NetBSD.
-v
- Boot in verbose mode.
-w
- Wait for a keypress before exiting loadbsd. This is useful when starting
this program under GEM.
-D
- Show debugging output while booting the kernel.
-S
amount
- Set the amount of available ST compatible RAM in bytes. Normally this
value is set automatically from the values initialized by the BIOS.
-T
amount
- Set the amount of available TT compatible RAM in bytes. Normally this
value is set automatically from the values initialized by the BIOS.
-V
- Print the version of
loadbsd(8) that you are
using.
- kernel-path
- This is a GEMDOS path specification of the kernel to boot.
Note: Because the loadbsd program can only read kernels from a
GEMDOS filesystem, the file /netbsd is usually not the
same as the actual kernel booted. This can cause some programs to fail.