freebsd kernel with SKQ
0f399181d3
intent was (and still is) that if a user has say
CPUTYPE=i686 set in /etc/make.conf, we don't print
the assignment type warning unless TARGET_CPUTYPE
is overridden.
Unfortunately, the implementation was buggy, and
only recent changes to bsd.cpu.mk that swapped
canonical and alias values of some CPU types made
the bug apparent.
Here's what happens here.
- CPUTYPE=i686 is set in /etc/make.conf,
- bsd.cpu.mk reset it to "pentiumpro",
- Makefile.inc1 compares this canonical value
with the result of the following test,
make -f /dev/null CPUTYPE=pentiumpro -V CPUTYPE
and expects the result to be "pentiumpro" too,
but "i686" is returned, here's why. We have two
CPUTYPE variables, global, set to "i686" in
/etc/make.conf, and command-line (of a higher
precedence), set to "pentiumpro".
The following part of bsd.cpu.mk,
. elif ${CPUTYPE} == "i686"
CPUTYPE = pentiumpro
which is responsible for converting aliases to
canonical values, sees the value of the CPUTYPE
command-line variable first, "pentiumpro", and
no conversion is done -- the net effect is that
CPUTYPE global stays with its old value "i686",
and "make -V CPUTYPE" (which prints variables
in the global context) returns "i686".
The fix was to pass the CPUTYPE in the test above
as an environment variable instead of as a command
line variable, i.e.,
CPUTYPE=pentiumpro make -f /dev/null -V CPUTYPE
This time, CPUTYPE global is still set to "i686"
initially (by /etc/make.conf), and an envieronment
variable CPUTYPE (of a lower precedence) is set
to "pentiumpro". The .elif sees it's set to
"i686" and resets it to "pentiumpro", and so
"make -V" returns "pentiumpro".
NB: these various types of make(1) variables can
be very painful, especially when combined with
"make -V".
|
||
|---|---|---|
| bin | ||
| contrib | ||
| crypto | ||
| etc | ||
| games | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| COPYRIGHT | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| 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 ``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. 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