BOOT(8) BSD System Manager's Manual BOOT(8) NNAAMMEE bboooott - system bootstrapping procedures DDEESSCCRRIIPPTTIIOONN PPoowweerr ffaaiill aanndd ccrraasshh rreeccoovveerryy.. 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 multi-user operations. CCoolldd ssttaarrttss.. 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 _v_m_u_n_i_x 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: device unit partition: where _d_e_v_i_c_e is the type of the device, assumed to be on the ISA bus, to be searched, _u_n_i_t is the unit number of the disk or tape, and _p_a_r_t_i_t_i_o_n 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 controller 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 _I_n_s_t_a_l_l_i_n_g _a_n_d _O_p_e_r_a_t_i_n_g _4_._3 _B_S_D_-_R_e_n_o _U_N_I_X _o_n _t_h_e _A_T_/_3_8_6 can be used to boot from a distribution tape. FFIILLEESS /vmunix system code /boot system bootstrap SSEEEE AALLSSOO halt(8), reboot(8), shutdown(8) BBUUGGSS The disklabel format used by this version of BSD is quite different from that of other architectures. 4.4BSD June 5, 1993 1