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7e8cc2bd03
revised/modified by me) to store dhcp options into kenv variables,
so the information is available to the boot loader and can be used
to customize the boot process.
The change is totally unintrusive, essentially made of a single
function to be called while parsing a dhcp response, and a couple
of tables to classify options. The values extracted from dhcp
options are stored in the kenv environment in one of these forms:
+ options whose name and type is known are saved as
dhcp.name = value (string, or number/ip addresses lists)
+ unknown options are assumed to be strings and saved as
dhcp.option-NNN = "value"
+ options listed as '__INDIR' and sent on the wire as e.g.
option unknown-252 "some.name=the actual value"
are saved as
some.name = "the actual value"
+ options listed as '__ILIST' and sent on the wire as e.g.
option unknown-249 "a.b=foo bar; c.d= 123; e.f=done"
are saved as multiple values
a.b="foo bar"
c.d="123"
e.f="done"
As you can see there is quite a bit of flexibility on what can
be passed to the loader or the kernel.
For the time being the vendor-specific table is mostly disabled,
because there is no standard set of options for FreeBSD, and I don't
know all the pxe-specific vendor options.
Also, applications using libstand may live in memory-constrained
environments, so it makes sense to keep these tables as small as
possible, especially considering that one can generate arbitrary
name=value pairs using site-specific options of type __INDIR or
__ILIST (there are 4 __ILIST and 5 __INDIR in the table, numbered
246..249 and 250..254).
Actually, considering that probably 75% of the standard dhcp options
are totally useless, it might make sense to remove them as well.
Submitted by: Danny Braniss
MFC after: 4 weeks
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| contrib | ||
| crypto | ||
| etc | ||
| games | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| ObsoleteFiles.inc | ||
| README | ||
| UPDATING | ||
This is the top level of the FreeBSD source directory. This file was last revised on: $FreeBSD$ For copyright information, please see the file COPYRIGHT in this directory (additional copyright information also exists for some sources in this tree - please see the specific source directories for more information). The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree, the most commonly used one being ``world'', which rebuilds and installs everything in the FreeBSD system from the source tree except the kernel, the kernel-modules and the contents of /etc. The ``world'' target should only be used in cases where the source tree has not changed from the currently running version. See: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html for more information, including setting make(1) variables. The ``buildkernel'' and ``installkernel'' targets build and install the kernel and the modules (see below). Please see the top of the Makefile in this directory for more information on the standard build targets and compile-time flags. Building a kernel is a somewhat more involved process, documentation for which can be found at: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html And in the config(8) man page. Note: If you want to build and install the kernel with the ``buildkernel'' and ``installkernel'' targets, you might need to build world before. More information is available in the handbook. The sample kernel configuration files reside in the sys/<arch>/conf sub-directory (assuming that you've installed the kernel sources), the file named GENERIC being the one used to build your initial installation kernel. The file NOTES contains entries and documentation for all possible devices, not just those commonly used. It is the successor of the ancient LINT file, but in contrast to LINT, it is not buildable as a kernel but a pure reference and documentation file. Source Roadmap: --------------- bin System/user commands. contrib Packages contributed by 3rd parties. crypto Cryptography stuff (see crypto/README). etc Template files for /etc. games Amusements. gnu Various commands and libraries under the GNU Public License. Please see gnu/COPYING* for more information. include System include files. kerberos5 Kerberos5 (Heimdal) package. lib System libraries. libexec System daemons. release Release building Makefile & associated tools. rescue Build system for statically linked /rescue utilities. sbin System commands. secure Cryptographic libraries and commands. share Shared resources. sys Kernel sources. tools Utilities for regression testing and miscellaneous tasks. usr.bin User commands. usr.sbin System administration commands. For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html