Build userland examples separately

packages/kernel_modules/Makefile

@@ -1,4 +1,13 @@
+ifeq ($(OBJECT_FILES),)
+obj-m += $(addsuffix .o, $(notdir $(basename $(filter-out %.mod.c, $(wildcard $(BR2_EXTERNAL_KERNEL_MODULES_PATH)/*.c)))))
+else
+# Trying to do:
+# $(MAKE) -C '$(LINUX_DIR)' M='$(M)' hello.ko hello2.ko
+# to restrict which modules are built leads to failures
+# when doing parallel builds. The only solution I could find
+# was to let the host select obj-m itself.
 obj-m += $(OBJECT_FILES)
+endif
 ccflags-y := -DDEBUG -g -std=gnu99 -Werror -Wno-declaration-after-statement -Wframe-larger-than=1000000000
 
 .PHONY: all

packages/kernel_modules/external.mk

@@ -19,10 +19,10 @@ ifeq ($(BR2_PACKAGE_OPENBLAS),y)
 endif
 
 define KERNEL_MODULES_BUILD_CMDS
-	$(MAKE) -C '$(@D)/user' $(TARGET_CONFIGURE_OPTS) \
-	  BR2_PACKAGE_EIGEN="$(BR2_PACKAGE_EIGEN)" \
-	  BR2_PACKAGE_LIBDRM="$(BR2_PACKAGE_LIBDRM)" \
-	  BR2_PACKAGE_OPENBLAS="$(BR2_PACKAGE_OPENBLAS)" \
+	$(MAKE) -C '$(@D)/userland' $(TARGET_CONFIGURE_OPTS) \
+	  HAS_EIGEN="$(BR2_PACKAGE_EIGEN)" \
+	  HAS_LIBDRM="$(BR2_PACKAGE_LIBDRM)" \
+	  HAS_OPENBLAS="$(BR2_PACKAGE_OPENBLAS)" \
 	;
 endef
 
@@ -33,7 +33,7 @@ define KERNEL_MODULES_INSTALL_TARGET_CMDS
 	#
 	# Modules can be still be easily inserted with "modprobe module" however.
 	$(INSTALL) -D -m 0655 $(@D)/*.ko '$(TARGET_DIR)'
-	$(INSTALL) -D -m 0755 $(@D)/user/*.out '$(TARGET_DIR)'
+	$(INSTALL) -D -m 0755 $(@D)/userland/*.out '$(TARGET_DIR)'
 endef
 
 $(eval $(kernel-module))

packages/kernel_modules/user/README.adoc

@@ -1,3 +0,0 @@
-https://github.com/cirosantilli/linux-kernel-module-cheat#rootfs_overlay
-
-. link:sched_getaffinity.c[]

packages/kernel_modules/userland/Makefile

@@ -10,7 +10,7 @@ OUT_EXT = .out
 OUT_DIR = .
 
 OUTS := $(foreach IN_EXT,$(IN_EXT_C) $(IN_EXT_CXX),$(addsuffix $(OUT_EXT), $(basename $(wildcard *$(IN_EXT)))))
-ifeq ($(BR2_PACKAGE_EIGEN),y)
+ifeq ($(HAS_EIGEN),y)
 	CXXFLAGS_EXTRA += -I$(STAGING_DIR)/usr/include/eigen3
 	# TODO: was failing with:
 	# fatal error: Eigen/Dense: No such file or directory as of
@@ -20,26 +20,27 @@ ifeq ($(BR2_PACKAGE_EIGEN),y)
 else
 	OUTS := $(filter-out eigen_%$(OUT_EXT),$(OUTS))
 endif
-ifeq ($(BR2_PACKAGE_LIBDRM),y)
+ifeq ($(HAS_LIBDRM),y)
 	LIBS += $(shell $(PKG_CONFIG) --libs libdrm)
 	CFLAGS_EXTRA += $(shell $(PKG_CONFIG) --cflags libdrm)
 else
 	OUTS := $(filter-out libdrm_%$(OUT_EXT),$(OUTS))
 endif
-ifeq ($(BR2_PACKAGE_OPENBLAS),y)
-	LIBS += -lopenblas
+ifeq ($(HAS_OPENBLAS),y)
+	LIBS += $(shell $(PKG_CONFIG) --libs openblas)
+	CFLAGS_EXTRA += $(shell $(PKG_CONFIG) --cflags openblas)
 else
-	OUTS := $(filter-out openblas$(OUT_EXT),$(OUTS))
+	OUTS := $(filter-out openblas_%$(OUT_EXT),$(OUTS))
 endif
 OUTS := $(addprefix $(OUT_DIR)/,$(OUTS))
 
 all: mkdir $(OUTS)
 
 $(OUT_DIR)/%$(OUT_EXT): %$(IN_EXT_C)
-	$(CC) $(CFLAGS) $(CFLAGS_EXTRA) -o '$@' '$<' $(LIBS)
+	$(CC) $(CFLAGS) $(CCFLAGS) $(CFLAGS_EXTRA) -o '$@' '$<' $(LIBS)
 
 $(OUT_DIR)/%$(OUT_EXT): %$(IN_EXT_CXX)
-	$(CXX) $(CXXFLAGS) $(CXXFLAGS_EXTRA) -o '$@' '$<' $(LIBS)
+	$(CXX) $(CXXFLAGS) $(CCFLAGS) $(CXXFLAGS_EXTRA) -o '$@' '$<' $(LIBS)
 
 clean:
 	rm -f *'$(OUT_EXT)'

packages/kernel_modules/userland/external.desc

@@ -0,0 +1 @@
+name: USERLAND

packages/kernel_modules/userland/external.mk

@@ -0,0 +1,34 @@
+################################################################################
+#
+# kernel_modules
+#
+################################################################################
+
+KERNEL_MODULES_VERSION = 1.0
+KERNEL_MODULES_SITE = $(BR2_EXTERNAL_KERNEL_MODULES_PATH)
+KERNEL_MODULES_SITE_METHOD = local
+
+ifeq ($(BR2_PACKAGE_EIGEN),y)
+	KERNEL_MODULES_DEPENDENCIES += eigen
+endif
+ifeq ($(BR2_PACKAGE_LIBDRM),y)
+	KERNEL_MODULES_DEPENDENCIES += libdrm
+endif
+ifeq ($(BR2_PACKAGE_OPENBLAS),y)
+	KERNEL_MODULES_DEPENDENCIES += openblas
+endif
+
+define KERNEL_MODULES_BUILD_CMDS
+	$(MAKE) -C '$(@D)' $(TARGET_CONFIGURE_OPTS) \
+	  BR2_PACKAGE_EIGEN="$(BR2_PACKAGE_EIGEN)" \
+	  BR2_PACKAGE_LIBDRM="$(BR2_PACKAGE_LIBDRM)" \
+	  BR2_PACKAGE_OPENBLAS="$(BR2_PACKAGE_OPENBLAS)" \
+	;
+endef
+
+define KERNEL_MODULES_INSTALL_TARGET_CMDS
+	$(INSTALL) -D -m 0755 $(@D)/*.out '$(TARGET_DIR)'
+endef
+
+$(eval $(kernel-module))
+$(eval $(generic-package))

packages/kernel_modules/userland/netlink.c

@@ -20,7 +20,7 @@ struct msghdr msg;
 struct nlmsghdr *nlh;
 struct sockaddr_nl src_addr, dest_addr;
 
-int main()
+int main(void)
 {
 	sock_fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_USER);
 	if (sock_fd < 0) {

packages/kernel_modules/userland/openblas_hello.c

@@ -6,7 +6,7 @@
 #include <assert.h>
 #include <cblas.h>
 
-int main()
+int main(void)
 {
 	double A[6] = {1.0, 2.0, 1.0, -3.0, 4.0, -1.0};
 	double B[6] = {1.0, 2.0, 1.0, -3.0, 4.0, -1.0};

packages/kernel_modules/userland/proc_events.c

@@ -5,7 +5,7 @@
 
 #if defined(__aarch64__)
 
-int main() {}
+int main(void) {}
 
 #else
 
@@ -147,7 +147,7 @@ static void on_sigint(__attribute__ ((unused)) int unused)
 	need_exit = true;
 }
 
-int main()
+int main(void)
 {
 	int nl_sock;
 	int rc = EXIT_SUCCESS;

packages/kernel_modules/userland/uio_read.c

@@ -66,7 +66,7 @@ int main(int argc, char **argv)
 #include <unistd.h>
 #include <unistd.h>
 
-int main()
+int main(void)
 {
     int uiofd;
     int configfd;