

BOOT(8)                   Minix Programmer's Manual                    BOOT(8)


NAME
     boot - from power on to the login prompt

DESCRIPTION
     At power on the machine reads the first sector of the  boot  device  into
     memory  and executes it.  This bootstrap code loads /boot, the Minix Boot
     Monitor.  The monitor loads the  kernel  binaries  from  /minix,  or  the
     newest file in /minix if it is a directory.

     The  Minix  system  is  now  running,  the  different  tasks   initialize
     themselves and control is transferred to the last one, init.

     Init is the grandparent of all Minix processes,  it  is  responsible  for
     starting login processes on each terminal, but first it runs /etc/rc.

     /etc/rc checks the state of the system and starts daemons.  First it sets
     the  keyboard  translation  to  the  mapping  in  /etc/keymap if present,
     followed by a call to readclock(8) to set Minix time  from  the  hardware
     clock.   Next the file systems are checked if necessary and the /usr file
     system is mounted.

     The system is now ready for multiuser startup, /etc/rc calls  /usr/etc/rc
     that cleans out /tmp, /usr/tmp, and resets or cycles log files by running
     /usr/etc/daily, starts the update(8) and cron(8) daemons, and initializes
     the  network services.  /etc/rc finally runs /usr/local/etc to initialize
     the system in a site or host dependent way.

     Init reads /etc/ttytab and starts a getty(8) for  each  enabled  terminal
     line to allow a user to log in.

OPTIONS

     bootopts=-s
          The value of the boot variable bootopts is passed to /etc/rc.  If it
          contains  -s  then  the  system  will run a single user shell before
          continuing with multiuser startup.  (Note  that  one  normally  uses
          boot -s instead of setting bootopts.)

     bootopts=-a
          This flag tells that /etc/fstab must be ignored.   The  system  asks
          for  a device to use as /usr instead.  This will also be done if the
          root device is not as mentioned in /etc/fstab.

     bootopts=-f
          Force a file  system  check,  even  if  the  system  was  shut  down
          properly.   (Do  this  once in a while to be sure about the state of
          the file systems.)





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     servers=program[,program...]
          Names the special servers that must be started in /usr/etc/rc.   The
          setting servers=inet will start the TCP/IP server.

BOOT ENVIRONMENT
     Many features of the drivers inside the kernel are controlled by settings
     in  the  boot  environmenti,  like  bootopts above does for /etc/rc.  The
     values of these variables are usually colon or  comma  separated  numbers
     configuring  the driver.  DPETH0 = 300:10 tells the DP 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.)

     Variables that are special  to  both  the  monitor  and  the  kernel  are
     described  in monitor(8).  This section lists extra variables or variable
     settings:

     cn = at | bios | esdi | xt | aha1540 | dosfile | fatfile
          Choose the driver that is to be used  as  controller  n,  in  order:
          IBM/AT  (classic  AT  or  newer  IDE),  BIOS  (any disk), ESDI (some
          PS/2s), IBM/XT, Adaptec 154x, Minix under DOS "file  as  disk",  FAT
          file  system  "file  as  disk".   By  default  at  is used on AT bus
          systems, bios on PS/2s and XTs, and dosfile when running under  DOS.
          Most  drivers  are  present in the kernel as distributed, but may be
          taken   out   by   modifying    /usr/include/minix/config.h.     See
          controller(4).  (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.)

     DPETHn = on | off
          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.

     DPETHn = I/O-addr:irq:mem_addr:mem_size  (WD80x3)
     DPETHn = I/O-addr:irq:0                  (NE2000)
     DPETHn = I/O-addr:irq:flags              (3c503)
          Set the I/O address (hex),  IRQ  (decimal),  memory  address  (hex),
          memory  size  (hex),  or  flags (hex) of the n-th ethernet board and
          turn it on.  By default  they  are  configured  as  280:3:D0000  and
          300:5:C8000  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


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          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 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.)

     DPETHn_EA = e0:e1:e2:e3:e4:e5
          Set the ethernet address of the 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.)

     AHA0 = I/O-addr:bus-on:bus-off:tr-speed
          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.

     aha1540-dn = sleep-time:target,lun
          Program SCSI disk 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 aha1540-dn variable that would be used had it
          been a disk.  So tape device c0t7 can be set to target 4, lun 1 with
          aha1540-d7=:4,1.  (The sleep-time parameter is present  but  ignored
          to be compatible with Minix-vmd.)

     dosfile-dn = file
          Tells the DOS virtual disk driver for disk n to use a given file  as
          a  disk.   The file is a DOS file name that the boot monitor must be
          able to open.

     fatfile-dn = driver:minor:file
          Tells the FAT virtual disk driver for disk n to use a given file  as
          a disk.  The driver parameter is the name of driver that handles the
          disk, and minor is the device number of the partition where the file
          is  found.   See  controller(4)  for  names  and  numbers.  The file
          argument is the path to the file from the root directory down.   The
          driver  named  must also be tied to a controller with a cn variable,
          so that the FAT file driver can find it.



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     TZ = GMT0
          This sets the time zone the hardware clock is running in.  Readclock
          uses  this  to correctly obtain the time of the clock.  The timezone
          of the system  is  set  in  /etc/profile.   This  boot  variable  is
          normally not set, only a few UNIX die-hards who don't care about the
          time Windows sees and don't want to change the clock  twice  a  year
          for daylight savings use this option.  (Set Windows time to the time
          zone of Casablanca to match.)

TCP/IP CONFIGURATION
     To use TCP/IP you need to run the inet server, and unless you are running
     standalone  you  have to enable the ethernet driver.  See the servers and
     DPETHn boot variables 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, may also work.

     You are likely to use TCP/IP in one of three situations:

          Standalone with no connection to a network.

          In a small network with no support from a "big" host.

          Connected to a large network with address and name servers.

     In each situation you need a different set of configuration files.

  Standalone
     All you need is a name and an IP address.  Suppose the name is  "flotsam"
     and the IP address is 192.168.0.1 from the private IP space, then this is
     put in /etc/hosts:

          192.168.0.1   flotsam

     And this in /etc/dhcpd.conf:

          host 192.168.0.0/24 {};
          interface ip0 flotsam;

  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 of your
     machine  and  host  names  of  all  machines  in  the  hosts   and   DHCP
     configuration  files.  Suppose your machine is to be named "flotsam", and
     another machine in the network is named "jetsam", and let's  use  network
     192.168.0.0/24 again.  The file /etc/hosts now looks like this:

          192.168.0.1   flotsam
          192.168.0.2   jetsam



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     And /etc/dhcp.conf like this:

          host 192.168.0.0/24 {};
          client 0:1:1b:a:68:ce flotsam;

     Use hostaddr -e to find out what the ethernet  address  of  your  network
     card is.  (The address above is an example.)

     A host needs to have all hostnames used on your  little  network  in  its
     host  file.   In the DHCP configuration you only need the client entry of
     the system itself, but it may be useful to add all client entries to make
     them all the same.

     If one of the machines is always on when any of the others is,  then  you
     can  let  it  be a DHCP server.  The other machines don't need a hosts or
     DHCP file anymore.  If flotsam is  the  server  then  its  /etc/dhcp.conf
     looks like this:

          host 192.168.0.0/24 {
              DNSserver flotsam;
          };
          client 0:1:1b:a:68:ce flotsam { option server; };
          client 0:0:c0:3a:12:10 jetsam;

  Large Network
     In a network with a central  network  administration  your  machine's  IP
     address  and  name  are  given  by  the  DHCP server.  You don't need any
     configuration files.  If you want your machine to do more, like  being  a
     router or something, then see inet(8) on setting up more networks.

  Simpler configuration tools
     The dhcpd and 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, dhcpd, can be replaced by:

          ifconfig -h host-IP-address -n netmask
          add_route -g gateway-IP-address

     to set the IP address and netmask of the machine.  Note that you can only
     do  this  if  the  machine has a static IP address, or chaos will follow.
     Remove /usr/adm/dhcp.cache if the DHCP daemon has run before.

     The name daemon, nonamed, can be replaced by an entry in /etc/resolv.conf
     that specifies an external name daemon:





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          nameserver nameserver-IP-address

     The ifconfig and add_route calls can be placed in the  file  /etc/rc.net.
     Check  /usr/etc/rc to see how /etc/rc.net can be used to override running
     the normal series of network deamons.  Note that /etc/rc.net is  sourced,
     so  you  can  use the same variables and functions that /usr/etc/rc uses.
     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.)

FILES

     /boot               Minix Boot Monitor.

     /minix              Kernel image, or directory containing them.

     /etc/rc             Basic system initialization.

     /usr/etc/rc         Complete system initialization.

     /etc/rc.net         Specialized network initialization.

     /usr/local/etc/rc   Per site initialization.

     /etc/hosts          Name to IP address mapping.

     /etc/dhcp.conf      Network initialization.

     /etc/resolv.conf    Name resolver configuration.

SEE ALSO
     monitor(8),  init(8),  inet(8),   loadkeys(8),   readclock(8),   fsck(1),
     fstab(5),   update(8),   cron(8),   ttytab(5),   getty(8),   hostaddr(1),
     ifconfig(8),  dhcpd(8),   nonamed(8),   tcpd(8),   hosts(5),   ethers(5),
     resolv.conf(5), inet(8).

DIAGNOSTICS

     Checking File Systems.
          If the system has crashed then fsck is called for the root and  /usr
          file  systems.  It is wise to reboot if the root file system must be
          fixed.

     Finish the name of device to mount as /usr: /dev/
          The prompt for the -a option, or if the name of the /usr file system
          has  not  been  set  in /etc/fstab.  You can type a device name, say
          fd0.



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     Unable to obtain an IP address after 10 seconds.
          TCP/IP misconfiguration.  The DHCP daemon may  have  failed  because
          the ethernet address of the machine is not known to the DHCP server,
          the DHCP configuration is not filled in properly, or the DHCP server
          can  not  be reached.  Either talk to your Network Administrator, or
          make a dhcp.conf and a hosts file.

     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.

NOTES
     The 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 networks  can  be  used
     for  private networks.  (This so-called CIDR notation names an IP address
     and the number of bits in the network number.  So 172.16.0.0/12  includes
     all addresses from 172.16.0.0 to 172.31.255.255.)  RFC-1597 will tell you
     why private networks are good, and RFC-1627 why they are bad.

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.

AUTHOR
     Kees J. Bot <kjb@cs.vu.nl>























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