BOOT(8) BSD System Manager's Manual BOOT(8)
b
\bbo
\boo
\bot
\bt - system bootstrapping procedures
D
\bDE
\bES
\bSC
\bCR
\bRI
\bIP
\bPT
\bTI
\bIO
\bON
\bN
P
\bPo
\bow
\bwe
\ber
\br f
\bfa
\bai
\bil
\bl a
\ban
\bnd
\bd c
\bcr
\bra
\bas
\bsh
\bh r
\bre
\bec
\bco
\bov
\bve
\ber
\bry
\by.
\b. Normally, the system will reboot itself at
power-up or after crashes. An automatic consistency check of the file
systems will be performed, and unless this fails, the system will resume
C
\bCo
\bol
\bld
\bd s
\bst
\bta
\bar
\brt
\bts
\bs.
\b. The 386 PC AT clones attempt to boot the floppy disk drive A
(otherwise known as drive 0) first, and failing that, attempt to boot the
hard disk C (otherwise known as hard disk controller 1, drive 0). The
automatic boot will attempt to load _
\bv_
\bm_
\bu_
\bn_
\bi_
\bx from partition A of either the
floppy or the hard disk. This boot may be aborted by typing any charac-
ter on the keyboard repeatedly (four or five times at least) during the
operating system load phase, after which the bootstrap will prompt for
the file that you wish to load instead.
One exception to this is the `d' key, which will not abort the load but
instead silently force the DEBUG boot flags. The boot flags for an auto-
boot are 0, and 3 for the successive boot after an aborted autoboot se-
quence. No other provison is made for setting boot flags (yet). A spe-
cific device or bootstrap file may be used; for example,
The file specifications used for the boostrap when loaded with the
``askme'' flag (e.g. an aborted autoboot) are of the form:
where _
\bd_
\be_
\bv_
\bi_
\bc_
\be is the type of the device, assumed to be on the ISA bus, to
be searched, _
\bu_
\bn_
\bi_
\bt is the unit number of the disk or tape, and _
\bp_
\ba_
\br_
\bt_
\bi_
\bt_
\bi_
\bo_
\bn
is the disk partition or tape file number. Normal line editing charac-
ters can be used when typing the file specification. The following list
of supported devices may vary from installation to installation:
wd ST506, IDE, ESDI, RLL disks on a WD100[2367] or lookalike
fd 5 1/4" or 3 1/2" High density floppies
For example, to boot from a file system which starts at cylinder 0 of
unit 0 of an IDE disk, type ``wd0a:vmunix'' to the boot prompt;
``fd0a:vmunix'' would specify a 3 1/2" floppy drive 0 .
In an emergency, the bootstrap methods described in the paper _
\bI_
\bn_
\bs_
\bt_
\ba_
\bl_
\bl_
\bi_
\bn_
\bg
_
\ba_
\bn_
\bd _
\bO_
\bp_
\be_
\br_
\ba_
\bt_
\bi_
\bn_
\bg _
\b4_
\b._
\b3 _
\bB_
\bS_
\bD_
\b-_
\bR_
\be_
\bn_
\bo _
\bU_
\bN_
\bI_
\bX _
\bo_
\bn _
\bt_
\bh_
\be _
\bA_
\bT_
\b/_
\b3_
\b8_
\b6 can be used to boot from a
S
\bSE
\bEE
\bE A
\bAL
\bLS
\bSO
\bO
halt(8), reboot(8), shutdown(8)
The disklabel format used by this version of BSD is quite different from
that of other architectures.
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