kbuild: Add new Kbuild variable KBUILD_EXTRA_SYMBOLS

This patch adds a new (Kbuild) Makefile variable KBUILD_EXTRA_SYMBOLS. The space separated list of file names assigned to KBUILD_EXTRA_SYMBOLS is used when calling scripts/mod/modpost during stage 2 of the Kbuild process for non-kernel-tree modules. Signed-off-by: Richard Hacker <lerichi@gmx.net> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kbuild: Add new Kbuild variable KBUILD_EXTRA_SYMBOLS
This patch adds a new (Kbuild) Makefile variable KBUILD_EXTRA_SYMBOLS. The space separated list of file names assigned to KBUILD_EXTRA_SYMBOLS is used when calling scripts/mod/modpost during stage 2 of the Kbuild process for non-kernel-tree modules. Signed-off-by: Richard Hacker <lerichi@gmx.net> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Richard Hacker · Sam Ravnborg
1 parent 2d04b5ae1b
Showing 2 changed files with 16 additions and 1 deletions Side-by-side Diff
Documentation/kbuild/modules.txt
scripts/Makefile.modpost
@@ -486,7 +486,7 @@
 	Sometimes, an external module uses exported symbols from another
 	external module. Kbuild needs to have full knowledge on all symbols
 	to avoid spitting out warnings about undefined symbols.
-	Two solutions exist to let kbuild know all symbols of more than
+	Three solutions exist to let kbuild know all symbols of more than
 	one external module.
 	The method with a top-level kbuild file is recommended but may be
 	impractical in certain situations.
@@ -522,6 +522,13 @@
 		build is finished, a new Module.symvers file is created
 		containing the sum of all symbols defined and not part of the
 		kernel.
+
+	Use make variable KBUILD_EXTRA_SYMBOLS in the Makefile
+		If it is impractical to copy Module.symvers from another
+		module, you can assign a space separated list of files to
+		KBUILD_EXTRA_SYMBOLS in your Makfile. These files will be
+		loaded by modpost during the initialisation of its symbol
+		tables.
  
 === 8. Tips & Tricks
  
@@ -42,6 +42,13 @@
  
 include include/config/auto.conf
 include scripts/Kbuild.include
+
+ifneq ($(KBUILD_EXTMOD),)
+# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
+include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
+             $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
+endif
+
 include scripts/Makefile.lib
  
 kernelsymfile := $(objtree)/Module.symvers
@@ -69,6 +76,7 @@
  $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,)       \
  $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile)   \
  $(if $(KBUILD_EXTMOD),-I $(modulesymfile))      \
+ $(if $(iKBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(EXTRA_SYMBOLS))) \
  $(if $(KBUILD_EXTMOD),-o $(modulesymfile))      \
  $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S)      \
  $(if $(CONFIG_MARKERS),-K $(kernelmarkersfile)) \
...	...	@@ -486,7 +486,7 @@
486	486	Sometimes, an external module uses exported symbols from another
487	487	external module. Kbuild needs to have full knowledge on all symbols
488	488	to avoid spitting out warnings about undefined symbols.
489		- Two solutions exist to let kbuild know all symbols of more than
	489	+ Three solutions exist to let kbuild know all symbols of more than
490	490	one external module.
491	491	The method with a top-level kbuild file is recommended but may be
492	492	impractical in certain situations.
...	...	@@ -522,6 +522,13 @@
522	522	build is finished, a new Module.symvers file is created
523	523	containing the sum of all symbols defined and not part of the
524	524	kernel.
	525	+
	526	+ Use make variable KBUILD_EXTRA_SYMBOLS in the Makefile
	527	+ If it is impractical to copy Module.symvers from another
	528	+ module, you can assign a space separated list of files to
	529	+ KBUILD_EXTRA_SYMBOLS in your Makfile. These files will be
	530	+ loaded by modpost during the initialisation of its symbol
	531	+ tables.
525	532
526	533	=== 8. Tips & Tricks
527	534
...	...	@@ -42,6 +42,13 @@
42	42
43	43	include include/config/auto.conf
44	44	include scripts/Kbuild.include
	45	+
	46	+ifneq ($(KBUILD_EXTMOD),)
	47	+# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
	48	+include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
	49	+ $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
	50	+endif
	51	+
45	52	include scripts/Makefile.lib
46	53
47	54	kernelsymfile := $(objtree)/Module.symvers
...	...	@@ -69,6 +76,7 @@
69	76	$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \
70	77	$(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
71	78	$(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
	79	+ $(if $(iKBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(EXTRA_SYMBOLS))) \
72	80	$(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
73	81	$(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \
74	82	$(if $(CONFIG_MARKERS),-K $(kernelmarkersfile)) \