390 lines
8.1 KiB
Text
390 lines
8.1 KiB
Text
|
.TH BOOT 8
|
||
|
|
.SH NAME
|
||
|
|
boot \- connect to the root file server
|
||
|
|
.SH SYNOPSIS
|
||
|
|
.B /boot/boot
|
||
|
|
[
|
||
|
|
.B -fkm
|
||
|
|
]
|
||
|
|
[
|
||
|
|
.BI -u username
|
||
|
|
]
|
||
|
|
[
|
||
|
|
.IB method ! fs-addr
|
||
|
|
]
|
||
|
|
[
|
||
|
|
.I args
|
||
|
|
]
|
||
|
|
.SH DESCRIPTION
|
||
|
|
.I Boot
|
||
|
|
is the first program run after a kernel has been loaded.
|
||
|
|
It connects to the file server that will serve the
|
||
|
|
root, performs any authentication needed to
|
||
|
|
connect to that server, and
|
||
|
|
.IR exec (2)'s
|
||
|
|
the
|
||
|
|
.IR init (8)
|
||
|
|
program.
|
||
|
|
It is started by the kernel, never run directly by the user. See
|
||
|
|
.IR booting (8)
|
||
|
|
for information about the process of loading the kernel (and
|
||
|
|
.IR boot )
|
||
|
|
into memory.
|
||
|
|
.PP
|
||
|
|
Once loaded, the kernel initializes its data structures and devices.
|
||
|
|
It sets the two environment variables
|
||
|
|
.B /env/cputype
|
||
|
|
and
|
||
|
|
.B /env/terminal
|
||
|
|
to describe the processor.
|
||
|
|
It then binds a place-holder file server,
|
||
|
|
.IR root (3),
|
||
|
|
onto
|
||
|
|
.B /
|
||
|
|
and crafts an initial process whose sole function is to
|
||
|
|
.IR exec (2)
|
||
|
|
.BR /boot/boot ,
|
||
|
|
a binary which is compiled into
|
||
|
|
.IR root (3).
|
||
|
|
.PP
|
||
|
|
The command line passed depends
|
||
|
|
on the information passed from boot ROM
|
||
|
|
to kernel.
|
||
|
|
Machines that boot directly from ROM (that is, most machines other than PCs)
|
||
|
|
pass the boot line given to the ROM directly to
|
||
|
|
.IR boot .
|
||
|
|
.PP
|
||
|
|
On the PC, each line in the DOS file
|
||
|
|
.B plan9.ini
|
||
|
|
of the form
|
||
|
|
.IB name = value
|
||
|
|
is passed to the boot program as an environment
|
||
|
|
variable with the same name and value.
|
||
|
|
The command line is
|
||
|
|
.IP
|
||
|
|
.B /386/9dos
|
||
|
|
.IB method ! server
|
||
|
|
.PP
|
||
|
|
(The first argument is ignored by
|
||
|
|
.IR boot .)
|
||
|
|
.I Boot
|
||
|
|
must determine the file
|
||
|
|
.I server
|
||
|
|
to use
|
||
|
|
and a
|
||
|
|
.I method
|
||
|
|
with which to connect to it.
|
||
|
|
Typically this will name a file server on the network,
|
||
|
|
or state that the root file system is on local disk and name the partition.
|
||
|
|
The complete list of methods is given below.
|
||
|
|
.PP
|
||
|
|
.I Boot
|
||
|
|
must also set a user name to be used
|
||
|
|
as the owner of devices and all console
|
||
|
|
processes and an encryption key to be used
|
||
|
|
when challenged.
|
||
|
|
.I Boot
|
||
|
|
will prompt for these.
|
||
|
|
.PP
|
||
|
|
Method and address are prompted for first.
|
||
|
|
The prompt lists all valid methods, with the default in brackets, for example:
|
||
|
|
.IP
|
||
|
|
.EX
|
||
|
|
root is from (tcp, local!#S/sdC0/fs)[tcp]:
|
||
|
|
.EE
|
||
|
|
.PP
|
||
|
|
A newline picks the default.
|
||
|
|
Other possible responses are
|
||
|
|
.I method
|
||
|
|
or
|
||
|
|
.IB method ! address\f1.
|
||
|
|
To aid in automatic reboot, the default is automatically
|
||
|
|
taken on CPU servers if nothing is typed within 15 seconds.
|
||
|
|
.PP
|
||
|
|
The other interactions depend on whether the system
|
||
|
|
is a
|
||
|
|
terminal or a CPU server.
|
||
|
|
.SS Terminal
|
||
|
|
The terminal must have a
|
||
|
|
.I username
|
||
|
|
to set.
|
||
|
|
If none is specified with the
|
||
|
|
.B -u
|
||
|
|
option,
|
||
|
|
.I boot
|
||
|
|
will prompt for one on the console:
|
||
|
|
.IP
|
||
|
|
.EX
|
||
|
|
user:
|
||
|
|
.EE
|
||
|
|
.PP
|
||
|
|
The user will also be prompted for a password to
|
||
|
|
be used as an encryption key on each
|
||
|
|
.IR attach (5):
|
||
|
|
.IP
|
||
|
|
.EX
|
||
|
|
password:
|
||
|
|
.EE
|
||
|
|
.PP
|
||
|
|
With most
|
||
|
|
.I methods
|
||
|
|
.I boot
|
||
|
|
can now connect to the file server.
|
||
|
|
However, with the serial line
|
||
|
|
.I methods
|
||
|
|
.B 9600
|
||
|
|
and
|
||
|
|
.BR 19200 ,
|
||
|
|
the actual mechanics of setting up the complete connection
|
||
|
|
are too varied to put into the boot program.
|
||
|
|
Instead
|
||
|
|
.I boot
|
||
|
|
lets the user set up the connection.
|
||
|
|
It prints a prompt on the console and then simulates
|
||
|
|
a dumb terminal between the user and the serial line:
|
||
|
|
.IP
|
||
|
|
.EX
|
||
|
|
Connect to file system now, type ctrl-d when done.
|
||
|
|
(Use the view or down arrow key to send a break)
|
||
|
|
.EE
|
||
|
|
.PP
|
||
|
|
The user can now type at the modem to
|
||
|
|
dial the number. What is typed depends on
|
||
|
|
the modem and is beyond this discussion.
|
||
|
|
.PP
|
||
|
|
When the user types a control-D,
|
||
|
|
.I boot
|
||
|
|
stops simulating a terminal and starts the file
|
||
|
|
system protocol over the serial line.
|
||
|
|
.PP
|
||
|
|
Once connected,
|
||
|
|
.I boot
|
||
|
|
mounts
|
||
|
|
the root file system before
|
||
|
|
.B /
|
||
|
|
and makes the connection available as
|
||
|
|
.B #s/boot
|
||
|
|
for subsequent processes to
|
||
|
|
.B mount
|
||
|
|
(see
|
||
|
|
.IR bind (2)).
|
||
|
|
.I Boot
|
||
|
|
completes by
|
||
|
|
.IR exec (2)'ing
|
||
|
|
.B /$objtype/init
|
||
|
|
.BR -t .
|
||
|
|
If the
|
||
|
|
.B -m
|
||
|
|
option is given it is also passed as an option to
|
||
|
|
.IR init .
|
||
|
|
If the environment variable
|
||
|
|
.B init
|
||
|
|
is set (via
|
||
|
|
.IR plan9.ini (8)),
|
||
|
|
it is used as a command line to exec instead.
|
||
|
|
.PP
|
||
|
|
If the kernel has been built with the cache file system,
|
||
|
|
.IR cfs (4),
|
||
|
|
the local disk partition
|
||
|
|
.BI /dev/sd XX /cache
|
||
|
|
(where
|
||
|
|
.B XX
|
||
|
|
is a unit specifier)
|
||
|
|
exists, and the root file system is from a remote server,
|
||
|
|
then the kernel will insert a user level cache
|
||
|
|
process between the remote server and the local namespace
|
||
|
|
that caches all remote accesses on the local partition.
|
||
|
|
The
|
||
|
|
.B -f
|
||
|
|
flag commands
|
||
|
|
.B cfs
|
||
|
|
to reformat the cache partition.
|
||
|
|
.SS CPU Servers
|
||
|
|
The user owning devices and console processes on CPU servers
|
||
|
|
and that user's domain and encryption key are
|
||
|
|
read from NVRAM on all machines except PC's.
|
||
|
|
PC's keep the information in the disk partition
|
||
|
|
.BI /dev/sd XX /nvram\f1.
|
||
|
|
If a
|
||
|
|
.B -k
|
||
|
|
option is given or if no stored information is found
|
||
|
|
.I boot
|
||
|
|
will prompt for all three items and store them.
|
||
|
|
.IP
|
||
|
|
.EX
|
||
|
|
password:
|
||
|
|
authid: bootes
|
||
|
|
authdom: research.bell-labs.com
|
||
|
|
.EE
|
||
|
|
.PP
|
||
|
|
The key is used for mutual authentication of the server and its clients.
|
||
|
|
The domain and id identify the owner of the key.
|
||
|
|
.PP
|
||
|
|
Once connected,
|
||
|
|
.I boot
|
||
|
|
behaves as on the terminal except for
|
||
|
|
.IR exec (2)'ing
|
||
|
|
.B /$objtype/init
|
||
|
|
.BR -c .
|
||
|
|
.SS Booting Methods
|
||
|
|
The methods available to any system depend on what was
|
||
|
|
compiled into the kernel.
|
||
|
|
The complete list of booting methods are listed below.
|
||
|
|
.TP 8
|
||
|
|
.BR tcp
|
||
|
|
connect via Ethernet using the TCP protocol.
|
||
|
|
The
|
||
|
|
.I args
|
||
|
|
are passed to
|
||
|
|
.IR ipconfig (8)
|
||
|
|
when configuring the IP stack.
|
||
|
|
The
|
||
|
|
.IR plan9.ini (8)
|
||
|
|
variables
|
||
|
|
.B fs
|
||
|
|
and
|
||
|
|
.B auth
|
||
|
|
override the file server and authentication server IP addresses
|
||
|
|
obtained (if any) from DHCP during
|
||
|
|
.IR ipconfig (8).
|
||
|
|
.TP 8
|
||
|
|
.B local
|
||
|
|
connect to the local file system.
|
||
|
|
The first argument is a disk holding a file system.
|
||
|
|
.I Boot
|
||
|
|
inspects the disk.
|
||
|
|
If the disk is a
|
||
|
|
.IR fossil (4)
|
||
|
|
file system, it invokes
|
||
|
|
.B /boot/fossil
|
||
|
|
to serve it.
|
||
|
|
If the
|
||
|
|
.B venti
|
||
|
|
environment variable (really,
|
||
|
|
.IR plan9.ini (8)
|
||
|
|
variable) is set,
|
||
|
|
.I boot
|
||
|
|
first arranges for fossil to be able to
|
||
|
|
contact the named
|
||
|
|
.IR venti (8)
|
||
|
|
server.
|
||
|
|
The variable's value can take the following forms:
|
||
|
|
.RS
|
||
|
|
.TP
|
||
|
|
.B /dev/sdC0/arenas
|
||
|
|
the file should be a venti partition with a configuration
|
||
|
|
stored on it using
|
||
|
|
.I venti/conf
|
||
|
|
(see
|
||
|
|
.IR venti-fmt (8)).
|
||
|
|
.I Boot
|
||
|
|
will start a loopback IP interface on 127.0.0.1
|
||
|
|
and start
|
||
|
|
.I venti
|
||
|
|
announcing on
|
||
|
|
.B tcp!127.1!17034
|
||
|
|
for venti service
|
||
|
|
and
|
||
|
|
.B tcp!127.1!8000
|
||
|
|
for web service,
|
||
|
|
using the configuration stored in that partition.
|
||
|
|
.TP
|
||
|
|
.B /dev/sdC0/arenas tcp!*!17034
|
||
|
|
same as the last but specify an alternate venti service address.
|
||
|
|
In this example, using
|
||
|
|
.B *
|
||
|
|
will announce on all available IP interfaces (even ones configured later)
|
||
|
|
rather than just the loopback device.
|
||
|
|
The loopback interface is still configured.
|
||
|
|
.TP
|
||
|
|
.B /dev/sdC0/arenas tcp!*!17034 tcp!*!80
|
||
|
|
same as the last but specify alternate venti service and web addresses.
|
||
|
|
The loopback interface is still configured.
|
||
|
|
.TP
|
||
|
|
.B tcp!135.104.9.2!17034 \fR[ \fIargs\fR ]
|
||
|
|
the network address of a venti server running on a separate machine.
|
||
|
|
.I Boot
|
||
|
|
will configure the IP stack by passing
|
||
|
|
.IR args ,
|
||
|
|
if any, to
|
||
|
|
.IR ipconfig (8).
|
||
|
|
.RE
|
||
|
|
.PP
|
||
|
|
If the disk is not a
|
||
|
|
.IR fossil (4)
|
||
|
|
partition,
|
||
|
|
.I boot
|
||
|
|
invokes
|
||
|
|
.BR /boot/kfs .
|
||
|
|
A variety of programs, like
|
||
|
|
.I 9660srv
|
||
|
|
and
|
||
|
|
.IR dossrv (4)
|
||
|
|
masquerade as
|
||
|
|
.I kfs
|
||
|
|
to allow booting from alternate media formats,
|
||
|
|
so as long as the disk is not a
|
||
|
|
.I fossil
|
||
|
|
disk, no check is made that the disk is in fact
|
||
|
|
a
|
||
|
|
.I kfs
|
||
|
|
disk.
|
||
|
|
The args are passed to
|
||
|
|
.IR kfs (4).
|
||
|
|
.PP
|
||
|
|
For the
|
||
|
|
.B tcp
|
||
|
|
method,
|
||
|
|
the address must be a numeric IP address.
|
||
|
|
If no address is specified,
|
||
|
|
a file server address will be found from another
|
||
|
|
system on the network using the BOOTP protocol and
|
||
|
|
the Plan 9 vendor-specific fields.
|
||
|
|
.SH EXAMPLES
|
||
|
|
On PCs, the default arguments to boot are constructed using
|
||
|
|
the
|
||
|
|
.B bootargs
|
||
|
|
variable in
|
||
|
|
.IR plan9.ini (8).
|
||
|
|
.PP
|
||
|
|
Start
|
||
|
|
.IR kfs (4)
|
||
|
|
with extra disk buffers:
|
||
|
|
.IP
|
||
|
|
.EX
|
||
|
|
bootargs=local!#S/sdC0/fs -B 4096
|
||
|
|
.EE
|
||
|
|
.LP
|
||
|
|
Use an IP stack on an alternate ethernet interface
|
||
|
|
with a static address and fixed file server and authentication
|
||
|
|
server addresses.
|
||
|
|
.IP
|
||
|
|
.EX
|
||
|
|
fs=192.168.0.2
|
||
|
|
auth=192.168.0.3
|
||
|
|
bootargs=tcp -g 192.168.0.1 ether /net/ether1 \e
|
||
|
|
192.168.0.50 255.255.255.0
|
||
|
|
.EE
|
||
|
|
.LP
|
||
|
|
(The
|
||
|
|
.B bootargs
|
||
|
|
line is split only for presentation; it is one line in the file.)
|
||
|
|
.SH FILES
|
||
|
|
.B #s/boot
|
||
|
|
.br
|
||
|
|
.B #//boot/boot
|
||
|
|
.SH SOURCE
|
||
|
|
.B /sys/src/9/boot
|
||
|
|
.SH "SEE ALSO"
|
||
|
|
.IR root (3),
|
||
|
|
.IR dhcpd (8),
|
||
|
|
.IR init (8)
|
||
|
|
.SH BUGS
|
||
|
|
The use of
|
||
|
|
.B bootargs
|
||
|
|
in general is odd.
|
||
|
|
The configuration specification
|
||
|
|
for fossil and venti servers
|
||
|
|
is particularly odd, but it does
|
||
|
|
cover the common cases well.
|