kbuild: Disable depmod in cross-compile kernel build
PATCH 1/1 kbuild: Disable depmod in cross-compile kernel build
When building embedded systems in a cross-compile environment and populating a target's file system image, we don't want to run the depmod on the host as we may be building for a completely different architecture. Since there's no such thing as a cross-depmod, we just disable running depmod in the cross-compile case and we just run depmod on the target at bootup.
Makefile +5 -1
@@ -1032,7 +1032,11 @@ depmod_opts := -b $(INSTALL_MOD_PATH) -r endif PHONY += _modinst_post _modinst_post: _modinst_ - if [ -r System.map -a -x $(DEPMOD) ]; then $(DEPMOD) -ae -F System.map $(depmod_opts) $(KERNELRELEASE); fi + @if [ "$(CROSS_COMPILE)" = "" ]; then \ + if [ -r System.map -a -x $(DEPMOD) ]; then \ + $(DEPMOD) -ae -F System.map $(depmod_opts) $(KERNELRELEASE); \ + fi \ + fi else # CONFIG_MODULES
Signature · 3 lines
Deepak Saxena - [email protected] - http://www.plexity.net "He who sacrifices freedom for security deserves neither" - Ben Franklin
Quoted 10 lines · Deepak Saxena
When building embedded systems in a cross-compile environment and populating a target's file system image, we don't want to run the depmod on the host as we may be building for a completely different architecture. Since there's no such thing as a cross-depmod, we just disable running depmod in the cross-compile case and we just run depmod on the target at bootup.
Signed-off-by Armin Kuster <[email protected]>Signed-off-by Deepak Saxena <[email protected]>
The root problem is depmod that should understand more targets. But testing for CROSS_COMPILE is not good enough - we should test is host target and buildtarget differs.
I took a look at it and came up with the attached patch. This btw solves:
http://bugzilla.kernel.org/show_bug.cgi?id=3881
Sam
Makefile +12 -18
@@ -1030,19 +1030,12 @@ _modinst_: fi $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst -# If System.map exists, run depmod. This deliberately does not have a -# dependency on System.map since that would run the dependency tree on -# vmlinux. This depmod is only for convenience to give the initial +# This depmod is only for convenience to give the initial # boot a modules.dep even before / is mounted read-write. However the # boot script depmod is the master version. -ifeq "$(strip $(INSTALL_MOD_PATH))" "" -depmod_opts := -else -depmod_opts := -b $(INSTALL_MOD_PATH) -r -endif PHONY += _modinst_post _modinst_post: _modinst_ - if [ -r System.map -a -x $(DEPMOD) ]; then $(DEPMOD) -ae -F System.map $(depmod_opts) $(KERNELRELEASE); fi + $(call cmd,depmod) else # CONFIG_MODULES
@@ -1259,15 +1252,6 @@ _emodinst_: $(Q)mkdir -p $(MODLIB)/$(install-dir) $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst -# Run depmod only is we have System.map and depmod is executable -quiet_cmd_depmod = DEPMOD $(KERNELRELEASE) - cmd_depmod = if [ -r System.map -a -x $(DEPMOD) ]; then \ - $(DEPMOD) -ae -F System.map \ - $(if $(strip $(INSTALL_MOD_PATH)), \ - -b $(INSTALL_MOD_PATH) -r) \ - $(KERNELRELEASE); \ - fi - PHONY += _emodinst_post _emodinst_post: _emodinst_ $(call cmd,depmod)
@@ -1516,6 +1500,16 @@ quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs))) quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files))) cmd_rmfiles = rm -f $(rm-files) +# Run depmod only is we have System.map and depmod is executable +# and we build for the host arch +quiet_cmd_depmod = DEPMOD $(KERNELRELEASE) + cmd_depmod = \ + if [ -r System.map -a -x $(DEPMOD) -a "$(SUBARCH)" == "$(ARCH)" ]; then \ + $(DEPMOD) -ae -F System.map \ + $(if $(strip $(INSTALL_MOD_PATH)), -b $(INSTALL_MOD_PATH) -r) \ + $(KERNELRELEASE); \ + fi + a_flags = -Wp,-MD,$(depfile) $(KBUILD_AFLAGS) $(AFLAGS_KERNEL) \ $(NOSTDINC_FLAGS) $(KBUILD_CPPFLAGS) \