.TH BOOT 8
.SH NAME
boot \- from power on to the login prompt
.SH DESCRIPTION
.de SP
.if t .sp 0.4
.if n .sp
..
At power on the machine reads the first sector of the boot device into memory
and executes it.  This bootstrap code loads
.BR /boot ,
the Minix Boot Monitor.  The monitor loads the kernel binaries from
.BR /minix ,
or the newest file in
.B /minix
if it is a directory.
.PP
The Minix system is now running, the different tasks initialize themselves
and control is transferred to the last one,
.BR init .
.PP
.B Init
is the grandparent of all Minix processes, it is responsible for starting
login processes on each terminal, but first it runs
.BR /etc/rc .
.PP
.B /etc/rc
checks the state of the system and starts daemons.  First it sets the
keyboard translation to the mapping in
.B /etc/keymap
if present, then it reads the time zone from
.B /etc/timeinfo
followed by a call to
.BR readclock (8)
to set Minix time from the hardware clock.  Next the file systems are checked
if necessary and the
.B /usr
file system is mounted.
.PP
The system is now ready for multiuser startup,
.B /etc/rc
starts the
.BR update (8)
and
.BR cron (8)
daemons, and initializes the network services.
.B /etc/rc
finally recovers crashed editor buffers and cleans out the
.B tmp
directories.
.PP
.B Init
reads
.B /etc/ttytab
and starts a
.BR getty (8)
for each enabled terminal line to allow a user to log in.
.SH "BOOT ENVIRONMENT"
Many features of the drivers inside the kernel are controlled by settings in
the boot environment.  The values of these variables are usually colon or
comma separated numbers configuring the driver.
.B "DPETH0 = 300:10"
tells the ethernet driver to use I/O address 0x300, interrupt request
10, and the default memory address (0xD0000, values may be omitted) for the
first ethernet board.  (Note that IRQ 2 is redirected to IRQ 9 on AT's and
PS/2's, so use 9 if a device is jumpered for 2.)
.PP
Variables that are special to both the monitor and the kernel are described
in
.BR monitor (8).
This section lists extra variables or variable settings:
.TP
\fBhd\fR = \fBat\fR | \fBbios\fP | \fBesdi\fR | \fBxt\fR
Choose the driver that is to be used for the hard disk, in order: IBM/AT
(classic AT or newer IDE), BIOS (generic driver), ESDI (some PS/2's), or
IBM/XT.  By default the first of these drivers that is enabled is used.
Most drivers are present in the kernel as distributed, but may be taken out
by modifying
.BR /usr/include/minix/config.h .
(An XT should always use the BIOS driver, not the XT driver, because BIOS
calls are cheap on an XT.  The XT driver can be used on AT machines with an
old XT controller.)
See
.BR hd (4).
.TP
\fBdosd\fR = \fBfile\fR | \fBfat\fR
Choose the driver that is to be used as the "DOS virtual disk", either the
"file" or the "FAT" driver.
See
.BR dosd (4).
.TP
\fBDPETH\fIn\fR = \fBon\fR | \fBoff\fR
Turn an ethernet board on or off.  The driver is by default in "sink" mode
for all boards.  The sink mode allows one to use the driver without an
ethernet board installed.  The driver will play /dev/null for that device,
i.e. nothing comes in, and anything send out is dropped on the floor.  If
the board is turned on then the driver will use it to send out packets, if
it is turned off then the driver will fail for that board.
.PP
.if n .ta \w'DPETHn = I/O-addr:irq:mem_addr:mem_size'u+2m
.if t .ta \w'\fBDPETH\fIn\fR = \fII/O-addr\fR:\fIirq\fR:\fImem_addr\fR:\fImem_size\fR'u+2m
\fBDPETH\fIn\fR = \fII/O-addr\fR:\fIirq\fR:\fImem_addr\fR:\fImem_size\fR	(WD80x3)
.br
\fBDPETH\fIn\fR = \fII/O-addr\fR:\fIirq\fR:\fB0\fR	(NE2000)
.br
\fBDPETH\fIn\fR = \fII/O-addr\fR:\fIirq\fR:\fIflags\fR	(3c503)
.RS
Set the I/O address (hex), IRQ (decimal), memory address (hex), memory
size (hex), or flags (hex) of the
.IR n -th
ethernet board and turn it on.  By default they are configured as
280:3:D0000 and 300:5:CC000 with the memory size set to 2000, 4000, or 8000
depending on the type of board found.
For the Western Digital cards the IRQ must be what the board expects,
but the memory address is programmed into the board by the driver.
The SMC EtherEZ board, a WD8013 successor, has only 8K
memory.  This confuses the driver, so you need to explicitly specify the
board size as being 2000.
The memory address and size have no meaning for the Novell ethernet boards,
but the address may be explicitly set to zero to indicate that the board
.B is
a Novell ethernet board.
For the 3Com 3c503 the third parameter are flags, with the low bit indicates
that the on-board tranceiver must be used if 0 (thin ethernet), or that an
external tranceiver is used on the AUI port if set to 1.
The IRQ is software settable, and must be specified as 2 (XT), 3, 4, 5,
or 9 (AT).  The memory address is set on the board by jumpers.  The driver
does not support I/O mode for the 3c503.
(Note the little differences between board types.  For the 8003/8013 and
NE1000/NE2000 the IRQ is fixed and the memory address variable, for the
3c503 the IRQ is variable and the memory address is fixed, but need not be
specified.  Messy.)
.RE
.TP
\fBDPETH\fIn\fB_EA\fR = \fIe0\fR:\fIe1\fR:\fIe2\fR:\fIe3\fR:\fIe4\fR:\fIe5\fR
Set the ethernet address of the
.IR n -th
ethernet board.  The address is normally obtained from the ethernet board,
so only in exceptional circumstances is this setting ever needed.  (Use the
address of the main server if you want a career change.)
.TP
\fBAHA0\fR = \fII/O-addr\fR:\fIbus-on\fR:\fIbus-off\fR:\fItr-speed\fR
Configure the Adaptec 154xA SCSI host adapter to use the given I/O address
(hex), Bus-on time (decimal), Bus-off time (decimal) and transfer speed
(hex).  The default is 330:15:1:00.  The default transfer speed is always
5.0 Mb/s (code 00) ignoring the jumper settings.
.TP
\fBsd\fIn\fR = \fItarget\fR,\fIlun\fR
Program SCSI disk
.BI sd n
to have the given target and logical unit number.  The target and lun
of a tape or other SCSI device may be changed by setting the
.BI sd n
variable that would be used had it been a disk.  So tape device st7 can be
set to target 4, lun 1 with sd35=4,1.
.TP
\fBMCD\fR = \fII/O-addr\fR:\fIirq\fR
I/O address (hex) and IRQ (decimal) of the Mitsumi CD-ROM driver, by default
300:10.
.PP
\fBdosd\fIn\fR = \fIfile\fR
.br
\fBdosd\fIn\fR = \fIpartition:file\fR
.RS
Tells the DOS virtual disk driver for device
.BI dosd n
.RI ( n
is 0 or 5) to use a given MS-DOS file as a disk.  Depending on whether the
"file" or the "FAT" driver is being used
.BI dosd n
is either set to a normal DOS file name, or to a Minix hard disk partition
name followed by a simple DOS file name.
See
.BR dosd (4).
.RE
.SH "TCP/IP CONFIGURATION"
To use TCP/IP you have to compile a kernel with networking enabled, and
unless you are running standalone you have to enable the ethernet driver.
See the
.BI DPETH n
boot variable above.  The driver supports these ethernet cards:  Western
Digital 8003, Western Digital 8013, SMC Elite Ultra 16,
Novell NE1000 and NE2000, 3Com Etherlink II (3c503).  Many newer
variants of the WD8013, now under the SMC brand, are also supported.
.PP
You are likely to use TCP/IP in one of three situations:
.PP
.RS
Standalone with no connection to a network.
.SP
In a small network with no support from a "big" host.
.SP
Connected to a large network with address and name servers.
.RE
.PP
In each situation you need a different set of configuration files.
.SS Standalone
If
.B rarpd
notices that there is no connection to the outside world then it will
configure the default network to address
.BR 10.0.0.1 .
You need to create one file,
.BR /etc/hosts ,
that should look like this (using the name "flotsam" as the example name
of the machine):
.PP
.RS
.ta +\w'127.0.0.1'u+3n
127.0.0.1	localhost
.br
10.0.0.1	flotsam
.RE
.SS "Small Network"
In a network where the Minix machine can't obtain its IP address and name
from a different host you need specify the ethernet address to host name
translation in the
.B /etc/ethers
file for use by
.BR rarpd .
Suppose your machine is to be named "flotsam", and another machine in the
network is named "jetsam".  The file
.B /etc/ethers
should at least contain an entry for flotsam:
.PP
.RS
.ta +\w'0:0:c0:a:77:23'u+3n
0:0:c0:a:77:23	flotsam
.RE
.PP
Use
.B hostaddr \-e
to find out what the six octet ethernet address of a host is.  Use the address
as printed: lowercase hex digits, no leading zeros.
The
.B /etc/hosts
file shows all IP addresses of the machines flotsam needs to know about,
and the netmask of the 10.*.*.* network:
.PP
.RS
.ta +\w'255.0.0.0'u+3n
127.0.0.1	localhost
.br
10.0.0.1	flotsam
.br
10.0.0.2	jetsam
.br
255.0.0.0	0.0.0.10.in-addr.arpa
.RE
.PP
.B Warning!
Do not add ethernet addresses of diskless workstations to your ethers file.
A Sun for instance has the stupid habit of booting from the first RARP server
that answers, probably your Minix machine...
.SS "Large Network"
In a network with a central network administration your machine's IP address
and name are given by the RARP and name services of the special servers on
the network.  For a new machine you need to apply for an IP address and host
name with your network administrator supplying the ethernet address of your
machine.  You don't need any configuration files now, the
.B irdpd
and
.B nonamed
daemons automatically find a router and a name server.
.PP
Note that no knowledge of the IP address or hostname of the Minix machine
itself is necessary, it all comes from the RARP and name servers.  A series
of Minix machines can therefore set up identically.  Even if you have no RARP
or name servers you can still set them up identically if you list all the
Minix hosts in the hosts and ethers files.
.SS "Netmasks"
An important parameter of a network is the netmask.  A netmask is a bit mask
that you apply to IP addresses to find out if two IP addresses are on the
same network.  So if a network interface has address 172.16.102.65 with
netmask 255.255.255.224 then the 32 addresses 172.16.102.64 through
172.16.102.95 are all on the same network as 172.16.102.65.  The
.B rarpd
daemon figures out the netmask by repeatedly looking up the netmask
corresponding to an interfaces' network address: ip-address AND
current-netmask.  Suppose for example that the address for an interface is
172.16.102.65.  The initial netmask for this class B address is 255.255.0.0.
So we look up the netmask associated with 172.16.0.0 (172.16.102.65 &
255.255.0.0).  This lookup yields 255.255.255.0, so now look up 172.16.102.0
to find 255.255.255.224.  Lastly we look up 172.16.102.64 to find
255.255.255.224 again so we use it as the netmask.  These netmasks can be
specified in
.B /etc/hosts
as follows:
.PP
.RS
.ta +\w'255.255.255.224'u+3n
255.255.255.0	0.0.16.172.in-addr.arpa
.br
255.255.255.224	0.102.16.172.in-addr.arpa
.br
255.255.255.224	64.102.16.172.in-addr.arpa
.RE
.PP
This should not be necessary on a large network that has name servers if
the Network Administrators have done their jobs properly.  Check with
.B ifconfig
if the netmask is as it should be.  If not then try to find the netmask
manually with
.B host
commands on the appropriate *.*.*.in-addr.arpa names.  The initial netmask
you start with is 255.0.0.0 for a class A network (0.*.*.* to 127.*.*.*),
255.255.0.0 for a class B network (128.*.*.* to 191.*.*.*) and 255.255.255.0
for class C networks (192.*.*.* to 223.*.*.*).  If you've found the mistake
then you can either try to convince your Network Administrator to fix it,
or you can add the appropriate entries to /etc/hosts to please
.BR rarpd .
.SS "Simpler configuration tools"
The
.BR rarpd ,
.BR irdpd
and
.BR nonamed
daemons are complex little programs that try to obtain information about
their surroundings automatically to tell the machine what its place in the
network is.  It should come as no surprise that there are simpler utilities
to configure a machine.  On a memory starved machine it may even be wise to
configure a machine statically to get rid of the daemons.  The first daemon,
.BR rarpd ,
can be replaced by:
.PP
.RS
.B ifconfig \-h
.I host-IP-address
.B \-n
.I netmask
.RE
.PP
to set the IP address of the machine.  Note that this is only necessary if
there is no external RARP service.  The second daemon
.B irdpd
can be replaced by setting a static route:
.PP
.RS
.B add_route \-g
.I router-IP-address
.RE
.PP
(if there is a router.)  The last daemon,
.BR nonamed ,
can be replaced by an entry in
.B /etc/resolv.conf
that specifies an external name daemon:
.PP
.RS
.B nameserver
.I nameserver-IP-address
.RE
.PP
Edit
.B /etc/rc
just above the point where the network daemons are started to add the calls
to
.B ifconfig
and
.BR add_route .
Remove the names of the daemons that no longer needed.
Note that these changes undo all the efforts to make Minix TCP/IP
autoconfigurable.  Make very sure that all the IP addresses are correct, and
that the IP address of your machine is unique.  (Mistakenly using the
address of a main server will make all other machines look at your machine,
and will make all the users of all other machines look at you.)
.SH FILES
.TP 20n
/boot
Minix Boot Monitor.
.TP
/minix
Kernel image, or directory containing them.
.TP
/etc/rc
First of the system initialization files.
.TP
/etc/hosts
Name to IP address mapping.
.TP
/etc/ethers
Name to ethernet address mapping.
.TP
/etc/resolv.conf
Name resolver configuration.
.SH "SEE ALSO"
.BR monitor (8),
.BR init (8),
.BR inet (8),
.BR loadkeys (8),
.BR readclock (8),
.BR fsck (1),
.BR update (8),
.BR cron (8),
.BR ttytab (5),
.BR getty (8),
.BR hostaddr (1),
.BR ifconfig (8),
.BR irdpd (8),
.BR nonamed (8),
.BR rarpd (8),
.BR hosts (5),
.BR ethers (5),
.BR resolv.conf (5),
.BR netdefault (8).
.SH DIAGNOSTICS
.TP 5n
Checking File Systems.
If the system has crashed then
.B fsck
is called for the root and /usr file systems.  It is wise to reboot if the
root file system must be fixed.
.TP
Finish the name of device to mount as /usr: /dev/
If the name of the /usr file system has not been set in /etc/fstab.
You can type a device name, say
.BR fd0 .
.TP
hostaddr: unable to fetch IP address
TCP/IP misconfiguration.  The RARP may have failed because the ethernet
address of the machine is not entered in either the remote or the local
ethers file.  Either talk to your Network Administrator, or make an ethers
and a hosts file.
.TP
1.2.3.4 login:
If you see an IP address instead of a host name then the system failed to
translate the IP address.  Either talk to your Network Administrator to
have the reverse address translation tables fixed, or make a hosts file.
.SH NOTES
The 10.*.*.* network can be used for private networks.  Next to this class A
network there are 16 private class B networks, 172.16.*.* to 172.31.*.*, and
256 private class C networks, 192.168.0.* to 192.168.255.*.  RFC-1597 will
tell you why they are good, and RFC-1627 why they are bad.
.SH BUGS
Indefinite hangs are possible if I/O addresses or IRQ's are wrong.  A driver
may babble about addresses and IRQ's, but that does not mean that what it
says is true, it may just be configured that way.  It is very difficult to
find peripherals on a PC automatically, and Minix doesn't even try.
.PP
.B Rarpd
should learn to also speak the BOOTP and DHCP protocols.
.SH AUTHOR
Kees J. Bot (kjb@cs.vu.nl)