[src/trunk]: src/share/mk Add support for generating tramponlines in the modu...

[matt <matt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ba7190feae4a
branches:  trunk
changeset: 789122:ba7190feae4a
user:      matt <matt%NetBSD.org@localhost>
date:      Wed Aug 07 17:36:11 2013 +0000

description:
Add support for generating tramponlines in the module at link time.
This is done using some awk scripts and KMODTRAMPOLINE in <machine/asm.h>
It's not as efficient as having the kloader do it but it is a lot simpler.

diffstat:

 share/mk/bsd.kmodule.mk |  39 +++++++++++++++++++++++++++++++++++++--
 1 files changed, 37 insertions(+), 2 deletions(-)

diffs (65 lines):

diff -r 47f7c813591b -r ba7190feae4a share/mk/bsd.kmodule.mk
--- a/share/mk/bsd.kmodule.mk   Wed Aug 07 17:29:15 2013 +0000
+++ b/share/mk/bsd.kmodule.mk   Wed Aug 07 17:36:11 2013 +0000
@@ -1,4 +1,4 @@
-#      $NetBSD: bsd.kmodule.mk,v 1.38 2013/08/06 06:08:39 skrll Exp $
+#      $NetBSD: bsd.kmodule.mk,v 1.39 2013/08/07 17:36:11 matt Exp $
 
 # We are not building this with PIE
 MKPIE=no
@@ -27,7 +27,7 @@
 # relocations inside the loader and removing this workaround, as the
 # resulting code would be much faster.
 .if ${MACHINE_CPU} == "arm"
-CFLAGS+=       -mlong-calls
+CFLAGS+=       -fno-common
 .elif ${MACHINE_CPU} == "hppa"
 CFLAGS+=       -mlong-calls
 .elif ${MACHINE_CPU} == "powerpc"
@@ -104,11 +104,46 @@
 
 ${OBJS} ${LOBJS}: ${DPSRCS}
 
+.if ${MACHINE_CPU} == "arm"
+# The solution to limited branch space involves generating trampolines for
+# those relocations while creating the module, as the resulting code will
+# be much faster and simplifies the loader.
+ARCHDIR=       $S/modules/arch/${MACHINE_CPU}
+ASM_H=         $S/arch/${MACHINE_CPU}/include/asm.h
+CLEANFILES+=   tmp.o tmp.S ${KMOD}_tmp.o ${KMOD}_tramp.o ${KMOD}_tramp.S
+${KMOD}_tmp.o: ${OBJS} ${DPADD}
+       ${_MKTARGET_LINK}
+       ${LD} -r -o tmp.o ${OBJS}
+       ${LD} -r \
+               `${OBJDUMP} --syms --reloc tmp.o | \
+                       ${TOOL_AWK} -f ${ARCHDIR}/kmodwrap.awk` \
+                -o ${.TARGET} tmp.o
+
+${KMOD}_tramp.S: ${KMOD}_tmp.o ${ARCHDIR}/kmodtramp.awk ${ASM_H}
+       ${_MKTARGET_CREATE}
+       ${OBJDUMP} --syms --reloc ${KMOD}_tmp.o | \
+                ${TOOL_AWK} -f ${ARCHDIR}/kmodtramp.awk \
+                > tmp.S && \
+       mv tmp.S ${.TARGET}
+
+${PROG}: ${KMOD}_tmp.o ${KMOD}_tramp.o
+       ${_MKTARGET_LINK}
+.if exists(${ARCHDIR}/kmodhide.awk)
+       ${LD} -r -o tmp.o ${KMOD}_tmp.o ${KMOD}_tramp.o
+       ${OBJCOPY} \
+               `${NM} tmp.o | ${TOOL_AWK} -f ${ARCHDIR}/kmodhide.awk` \
+               tmp.o ${.TARGET} && \
+       rm tmp.o
+.else
+       ${LD} -r -o ${.TARGET} ${KMOD}_tmp.o ${KMOD}_tramp.o
+.endif
+.else
 ${PROG}: ${OBJS} ${DPADD}
        ${_MKTARGET_LINK}
        ${CC} ${LDFLAGS} -nostdlib -r -Wl,-T,${KMODSCRIPT},-d \
                -o ${.TARGET} ${OBJS}
 .endif
+.endif
 
 ##### Install rules
 .if !target(kmodinstall)