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Diffstat (limited to 'sbin/nextboot/nextboot.8')
-rw-r--r-- | sbin/nextboot/nextboot.8 | 116 |
1 files changed, 0 insertions, 116 deletions
diff --git a/sbin/nextboot/nextboot.8 b/sbin/nextboot/nextboot.8 deleted file mode 100644 index fa9882b..0000000 --- a/sbin/nextboot/nextboot.8 +++ /dev/null @@ -1,116 +0,0 @@ -.\" $FreeBSD$ -.Dd July 9, 1996 -.Dt NEXTBOOT 8 -.Os -.Sh NAME -.Nm nextboot -.Nd install a default bootstring block on the boot disk -.Sh SYNOPSIS -.Nm -.Op Fl b -.Ar filename bootstring -.Ar -.Nm -.Op Fl ed -.Ar filename -.Sh DESCRIPTION -The -.Fx -program -.Nm -controls the actions of the boot blocks at the time of the next boot. -If compiled with the correct option, -the boot blocks will check the nameblock for a magic number and a -default name to use for booting. -If compiled to do so they will also -delete the name from the block, ensuring that if the boot should fail, -then it will not be tried again. -It is the job of -.Pa /etc/rc -to use -.Nm -to re-install the string if that boot is found to have succeeded. -This allows a one-time only boot string to be used for such applications -as remote debugging, and installation of new, untrusted kernels. -The nameblock is defined at compile time to be the second physical block -on the disk. -.Pp -The following options are available: -.Bl -tag -width indent -.It Fl b -Is used for bootstrapping (initially configuring) the nameblock. -Without -this, -.Nm -will refuse to write to a block that does not already contain the magic -number. -.It Fl d -Disable (temporarily) an existing name block by changing a bit -in the magic number. -.It Fl e -Restore the good magic number on a block disabled by -.Fl d . -.El -.Pp -The -.Fl e -and -.Fl d -flags are mutually exclusive. -.Sh DESCRIPTION -.Nm Nextboot -first checks that the disk has an fdisk table and checks that none of the -partitions defined in that table include the nameblock. -If the name block is -shown to be unused, it will install the bootstrings given as arguments, -one after the other, each preceded by a small magic number, and NULL -terminated. -The end of the list of strings is delimited by a sequence of -0xff bytes. -If the boot blocks are compiled to write back the nameblock -after each boot, it will zero out the supplied names as it uses them, -one per boot, -until it reaches the 0xff, at which time it will revert to the compiled in -boot string. -At this time the nameblock will contain only zeroed out names. -.Pp -An example of usage might be: -.Bd -literal - nextboot -b /dev/rwd0 1:sd(0,a)/boot/kernel/kernel.experimental \\ - wd(0,a)/boot/kernel.old/kernel -.Ed -.Pp -Which would instruct the boot blocks at the next boot, -to try boot the experimental kernel off the SCSI disk. -If for any reason this failed, the next boot attempt would -boot the kernel -.Pa /boot/kernel.old/kernel -off the IDE drive. (Assuming the write-back option were enabled) If this -in turn failed. -The compiled in default would be used. -.Pp -If the write-back feature is disabled, the nextboot program is a convenient way -to change the default boot string. -Note, that should the file specified in -the nameblock be non-existent, then the name compiled into the boot blocks -will be used for the boot rather than the next name in the nameblock. -The -nameblock is only consulted -.Em once -per boot. -.Sh SEE ALSO -.Xr boot 8 , -.Xr disklabel 8 , -.Xr fdisk 8 -.Sh BUGS -This program works only in conjunction with the legacy boot code. -.Pp -The entire program should be made more user-friendly. -The option of whether to write back or not should be stored on the -disk and not a compile time option. -I want to rethink this at some -later stage to make it co-exist with disks that do not have -a fdisk partitioning table (i.e. purely disklabel'd systems). -.Pp -Whether to write back or not should be specified at run-time in the nameblock -so that the boot blocks need not be altered to get this feature. |