lx_emul: generate initcalls during build

Functions registered with 'module_init' (i.e., '__define_initcalls'),
'OF_DECLARE', and 'DECLARE_PCI_FIXUP_CLASS_FINAL' used to be static
constructors and had be explicitly registered using
'exec_static_constructors' before executing any Linux code.

With this commit we remove the constructor attributes from these
functions and create a global function pointer in the form of

__initptr_<name>_<id>_<counter>_<line number of macro>

'import-lx_emul_common.inc' will collect these '__initptr' symbols after
the compile step and generate a 'lx_emul_register_initcalls' function
that executes the functions pointed to. This step is now automatically
performed in 'lx_emul_start_kernel'. This way a call to
'exec_static_constructors' can be omitted in case there are no other
constructors in place.

issue #5096

repos/dde_linux/lib/import/import-lx_emul_common.inc

@@ -211,3 +211,57 @@ GLOBAL_DEPS += $(wildcard $(addsuffix /linux/*.h,$(SHADOW_INC_DIR))) \
 GLOBAL_DEPS += $(wildcard $(addsuffix /linux/*.h,$(SPEC_SHADOW_INC_DIR))) \
                $(wildcard $(addsuffix /asm/*.h,$(SPEC_SHADOW_INC_DIR)))
 
+
+#
+# Generate initcall_table.c and create 'lx_emul_register_initcalls' which  calls
+# global '__initptr_*' functions created by 'module_init'
+#
+
+define print_file_header
+echo "/*"                                                          > $(2);
+echo " * \\brief  Register initcalls from __initptr_*"            >> $(2);
+echo " * \\author Automatically generated file - do no edit"      >> $(2);
+echo " * \\date   $(1)"                                           >> $(2);
+echo " */"                                                        >> $(2);
+echo ""                                                           >> $(2);
+echo ""                                                           >> $(2);
+endef
+
+define print_declaration
+echo "extern void * $(1);" >> $(2);
+endef
+
+define print_function_start
+echo ""                                      >> $(1)
+echo "void lx_emul_register_initcalls(void)" >> $(1);
+echo "{"                                     >> $(1);
+echo "	typedef void (*func)(void);"         >> $(1);
+endef
+
+define print_call
+echo "	((func)$(1))();" >> $(2);
+endef
+
+define print_function_end
+echo "}" >> $(1);
+endef
+
+
+# 'module_init' calls should only be in C-sources
+WAIT_FOR_OBJECTS = $(addsuffix .o,$(basename $(filter-out initcall_table.c,$(SRC_C))))
+
+# retrieve 'initptr_*' using nm from object files
+INITCALLS = $(sort $(shell $(NM) -U $(WAIT_FOR_OBJECTS) |\
+              grep "__initptr" |\
+              awk '{print $$3}'))
+
+SRC_C += initcall_table.c
+
+initcall_table.c: $(WAIT_FOR_OBJECTS)
+	$(MSG_CONFIG)$@
+	@$(call print_file_header,$(shell date +"%F"),$@)
+	@$(foreach sym,$(INITCALLS),$(call print_declaration,$(sym),$@))
+	@$(call print_function_start,$@)
+	@$(foreach sym,$(INITCALLS),$(call print_call,$(sym),$@))
+	@$(call print_function_end,$@)
+

repos/dde_linux/src/include/lx_emul/init.h

@@ -20,6 +20,9 @@ extern "C" {
 
 void lx_emul_initcalls(void);
 
+/* this function is generated into 'initcall_table.c' */
+void lx_emul_register_initcalls(void);
+
 void lx_emul_register_initcall(int (*initcall)(void), const char * name);
 
 void lx_emul_start_kernel(void * dtb);

repos/dde_linux/src/include/lx_emul/shadow/include/linux/init.h

@@ -27,9 +27,16 @@
 #undef ___define_initcall
 #undef __define_initcall
 
-#define __define_initcall(fn, id) \
+/*
-	static void __initcall_##fn##id(void)__attribute__((constructor)); \
+ * Define local register function and global pointer to function in the form
-	static void __initcall_##fn##id() { \
+ * '__initptr_<function name>_<id>_<counter>_<line number of macro>'
-			lx_emul_register_initcall(fn, __func__); };
+ */
+#define __define_initcall(fn, id)                    \
+	static void __initcall_##fn##id(void) {            \
+		lx_emul_register_initcall(fn, __func__); }       \
+	                                                   \
+	void * __PASTE(__initptr_##fn##id##_,              \
+	       __PASTE(__COUNTER__,                        \
+	       __PASTE(_,__LINE__))) = __initcall_##fn##id;
 
 #endif /* _LX_EMUL__SHADOW__LINUX__INIT_H_ */

repos/dde_linux/src/include/lx_emul/shadow/include/linux/of.h

@@ -21,15 +21,19 @@
 #undef OF_DECLARE_2
 
 /* used to populate __clk_of_table */
-#define OF_DECLARE_1(table, name, compat, fn) \
+#define OF_DECLARE_1(table, name, compat, fn)                   \
-	static void __of_declare_initcall_##name(void) __attribute__((constructor)); \
+	static void __of_declare_initcall_##name(void) {              \
-	static void __of_declare_initcall_##name() { \
+			lx_emul_register_of_##table##_initcall(compat, fn); };    \
-			lx_emul_register_of_##table##_initcall(compat, fn); };
+	void * __PASTE(__initptr_of_declare_initcall_##name##_,       \
+	       __PASTE(__COUNTER__,                                   \
+	       __PASTE(_, __LINE__))) = __of_declare_initcall_##name;
 
 /* used to populate __irqchip_of_table */
-#define OF_DECLARE_2(table, name, compat, fn) \
+#define OF_DECLARE_2(table, name, compat, fn)                   \
-	static void __of_declare_initcall_##name(void) __attribute__((constructor)); \
+	static void __of_declare_initcall_##name(void) {              \
-	static void __of_declare_initcall_##name() { \
+			lx_emul_register_of_##table##_initcall(compat, fn); };    \
-			lx_emul_register_of_##table##_initcall(compat, fn); };
+	void * __PASTE(__initptr_of_declare_initcall_##name##_,       \
+	       __PASTE(__COUNTER__,                                   \
+	       __PASTE(_, __LINE__))) = __of_declare_initcall_##name;
 
 #endif /* _LX_EMUL__SHADOW__LINUX__OF_H_ */

repos/dde_linux/src/include/lx_emul/shadow/include/linux/pci.h

@@ -14,9 +14,13 @@
 #undef DECLARE_PCI_FIXUP_CLASS_FINAL
 
 #define DECLARE_PCI_FIXUP_CLASS_FINAL(vendor, device, class, \
-                     class_shift, hook) \
+                     class_shift, hook)                      \
-static void __pci_fixup_final_##hook(struct pci_dev *dev) __attribute__((constructor)); \
+static void __pci_fixup_final_##hook(struct pci_dev *dev) {  \
-static void __pci_fixup_final_##hook(struct pci_dev *dev) { \
+	lx_emul_register_pci_fixup(hook, __func__); };             \
-	lx_emul_register_pci_fixup(hook, __func__); };
+	void * __PASTE(__initptr_pci_fixup_final_##hook##_,        \
+	       __PASTE(__COUNTER__,                                \
+	       __PASTE(_, __LINE__))) = __pci_fixup_final_##hook;
+
+
 
 #endif /* _LINUX__PCI_H_ */

repos/dde_linux/src/lib/lx_emul/init.cc

@@ -52,6 +52,9 @@ extern "C" void lx_emul_start_kernel(void * dtb)
 {
 	using namespace Lx_kit;
 
+	/* register 'module_init' calls and friends */
+	lx_emul_register_initcalls();
+
 	new (env().heap) Task(lx_emul_init_task_function, dtb,
 	                      lx_emul_init_task_struct, SWAPPER_PID, "swapper",
 	                      env().scheduler, Task::TIME_HANDLER);

repos/pc/lib/import/import-pc_lx_emul.mk

@@ -44,7 +44,7 @@ SRC_C   += lx_emul/shadow/drivers/pci/search.c
 SRC_C   += lx_emul/shadow/drivers/pci/setup-irq.c
 SRC_C   += lx_emul/shadow/drivers/pci/setup-res.c
 SRC_CC  += lx_emul/pci.cc
-SRC_CC  += lx_emul/pci_bus.c
+SRC_C   += lx_emul/pci_bus.c
 SRC_CC  += lx_kit/device.cc
 SRC_CC  += lx_kit/memory_dma.cc