simplifying the module linking process and eliminating the risks
associated with doubly-defined variables.
Cases where commons were legitimately used (detection of
compiled-in subsystems) have been converted to use sysinits, and
any new code should use this or an equivalent practice as a
matter of course.
Modules can override this behaviour by substituting -fno-common
out of ${CFLAGS} in cases where commons are necessary
(eg. third-party object modules). Commons will be resolved and
allocated space when the kld is linked as part of the module
build process, so they will not pose a risk to the kernel or
other modules.
Provide a mechanism for controlling the export of symbols from
the module namespace. The EXPORT_SYMS variable may be set in the
Makefile to NO (export no symbols), a list of symbols to export,
or the name of a file containing a newline-seperated list of
symbols to be exported. Non-exported symbols are converted to
local symbols. If EXPORT_SYMS is not set, all global symbols are
currently exported. This behaviour is expected to change (to
exporting no symbols) once modules have been converted.
Reviewed by: peter (in principle)
Obtained from: green (kmod_syms.awk)
Assert that compilation takes place in a freestanding environment. This
implies `-fno-builtin'. A freestanding environment is one in which the
standard library may not exist, and program startup may not necessarily be
at main. The most obvious example is an OS kernel. This is equivalent to
`-fno-hosted'.
kern.post.mk.
# this should allow us to move kern.post.mk to the last line of the makefiles,
# but I'll do that slowly as I verify that one can do that w/o breaking things.
Submitted by: naddy
new files: kern.pre.mk, which contains most of the definitions, and
kern.post.mk, which contains most of the rules.
I've tested this on i386 and pc98. I have had feedback on the sparc64
port, but no reports from anybody on alpha, ia64 or powerpc. I
appologize in advance if I've broken you.
Reviewed by: jake, jhb, arch@
