Initiate the de-orbit burn sequence for <bsd.kern.mk>.

Always use sys/conf/kern.mk when building kernel/modules.
<bsd.kern.mk> is only preserved for sys/boot/pc98/boot2
for now, but this will be fixed.  If there are other
users of <bsd.kern.mk>, please let me know.

Reminded by:	bde

share/mk/bsd.kern.mk

@@ -1,59 +1,13 @@
 # $FreeBSD$
 
-#
-# Warning flags for compiling the kernel and components of the kernel.
-#
-# Note that the newly added -Wcast-qual is responsible for generating 
-# most of the remaining warnings.  Warnings introduced with -Wall will
-# also pop up, but are easier to fix.
-CWARNFLAGS?=	-Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \
-		-Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual \
-		-fformat-extensions -ansi
-#
-# The following flags are next up for working on:
-#	-W
-
-#
-# On the i386, do not align the stack to 16-byte boundaries.  Otherwise GCC
-# 2.95 adds code to the entry and exit point of every function to align the
-# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack
-# per function call.  While the 16-byte alignment may benefit micro benchmarks, 
-# it is probably an overall loss as it makes the code bigger (less efficient
-# use of code cache tag lines) and uses more stack (less efficient use of data
-# cache tag lines)
-#
-.if ${MACHINE_ARCH} == "i386"
-CFLAGS+=	-mno-align-long-strings -mpreferred-stack-boundary=2
+# Search for kernel source tree in standard places.
+.for _dir in ${.CURDIR}/../.. ${.CURDIR}/../../.. ${.CURDIR}/../../../.. /sys /usr/src/sys
+.if !defined(SYSDIR) && exists(${_dir}/conf/kern.mk)
+SYSDIR=	${_dir}
+.endif
+.endfor
+.if !defined(SYSDIR) || !exists(${SYSDIR}/kern) || !exists(${SYSDIR}/conf/)
+.error "can't find kernel source tree"
 .endif
 
-#
-# On the alpha, make sure that we don't use floating-point registers and
-# allow the use of BWX etc instructions (only needed for low-level i/o).
-# Also, reserve register t7 to point at per-cpu global variables.
-#
-.if ${MACHINE_ARCH} == "alpha"
-CFLAGS+=	-mno-fp-regs -ffixed-8 -Wa,-mev6
-.endif
-
-#
-# For IA-64, we use r13 for the kernel globals pointer and we only use
-# a very small subset of float registers for integer divides.
-#
-.if ${MACHINE_ARCH} == "ia64"
-CFLAGS+=	-ffixed-r13 -mfixed-range=f32-f127 -mno-sdata
-.endif
-
-#
-# For sparc64 we want medlow code model, and we tell gcc to use floating
-# point emulation.  This avoids using floating point registers for integer
-# operations which it has a tendency to do.
-#
-.if ${MACHINE_ARCH} == "sparc64"
-CFLAGS+=	-mcmodel=medlow -msoft-float
-.endif
-
-#
-# GCC 3.0 and above like to do certain optimizations based on the
-# assumption that the program is linked against libc.  Stop this.
-#
-CFLAGS+=	-ffreestanding
+.include "${SYSDIR}/conf/kern.mk"

sys/conf/kern.post.mk

@@ -221,4 +221,4 @@ majors.c: $S/conf/majors $S/conf/majors.awk
 majors.o:
 	${NORMAL_C}
 
-.include <bsd.kern.mk>
+.include "kern.mk"

sys/conf/kmod.mk

@@ -309,4 +309,4 @@ ${OBJS}: ${SRCS:M*.h}
 .endif
 
 .include <bsd.obj.mk>
-.include <bsd.kern.mk>
+.include "kern.mk"