feat: added support for constructors/desctructors

yak-kernel/CMakeLists.txt

@@ -67,12 +67,22 @@ if (NOT IS_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/src/platform/${CMAKE_SYSTEM_PRO
     message(FATAL_ERROR "Unknown architecture ${CMAKE_CURRENT_SOURCE_DIR}/src/platform/${CMAKE_SYSTEM_PROCESSOR}")
 endif ()
 
-file(GLOB PLATFORM_SPECIFIC_SOURCES src/platform/x86_64/*.c)
+file(GLOB PLATFORM_SPECIFIC_SOURCES src/platform/${CMAKE_SYSTEM_PROCESSOR}/*.c)
+file(GLOB PLATFORM_SPECIFIC_ASM_SOURCES src/platform/${CMAKE_SYSTEM_PROCESSOR}/*.asm)
+
+file(GLOB CRTI src/platform/generic/crt/crti.c)
+file(GLOB CRTN src/platform/generic/crt/crtn.c)
 
 # Define aggregate sources
-set(KERNEL_SOURCE_FILES ${KERNEL_SOURCES} ${LIMINE_KERNEL_SOURCES} ${PLATFORM_GENERIC_SOURCES} ${PLATFORM_SPECIFIC_SOURCES})
+set(KERNEL_SOURCE_FILES
+        ${KERNEL_SOURCES}
+        ${LIMINE_KERNEL_SOURCES}
+        ${PLATFORM_GENERIC_SOURCES}
+        ${PLATFORM_SPECIFIC_SOURCES}
+        ${PLATFORM_SPECIFIC_ASM_SOURCES}
+)
 
 # Define executable
-add_executable(yak.elf ${KERNEL_SOURCE_FILES})
+add_executable(yak.elf ${CRTI} ${KERNEL_SOURCE_FILES} ${CRTN})
 target_link_libraries(yak.elf PRIVATE ${BUILTINS_LIB})
 target_include_directories(yak.elf PRIVATE include ../limine/include ${printf_library_SOURCE_DIR}/src)# ${printf_library_SOURCE_DIR}/src)

yak-kernel/include/yak/platform/generic/platform.h

@@ -5,6 +5,18 @@
 #ifndef YAK_PLATFORM_H
 #define YAK_PLATFORM_H
 
+#if __x86_64__ || __x86_64
+#define HAS_INIT
+#endif
+
+#ifdef HAS_INIT
+void _init();
+void _fini();
+#else
+#define _init
+#define _fini
+#endif
+
 void platform_init();
 
 void __attribute__((noreturn)) halt_forever();

yak-kernel/linker.lds

@@ -23,6 +23,8 @@ SECTIONS
     . = 0xffffffff80000000;
 
     .text : {
+        *(.init)
+        *(.fini)
         *(.text .text.*)
     } :text
 
@@ -33,6 +35,20 @@ SECTIONS
         *(.rodata .rodata.*)
     } :rodata
 
+    /* Include the list of initialization functions sorted. */
+    .init_array :
+    {
+        KEEP (*(.init_array.*))
+        KEEP (*(.init_array))
+    } :rodata
+
+    /* Include the list of termination functions sorted. */
+    .fini_array :
+    {
+        KEEP (*(SORT(.fini_array.*)))
+        KEEP (*(.fini_array))
+    } :rodata
+
     /* Move to the next memory page for .data */
     . += CONSTANT(MAXPAGESIZE);
 

yak-kernel/src/platform/generic/crt/crti.c

@@ -0,0 +1,21 @@
+//
+// Created by rick on 9-5-23.
+//
+// Based upon https://wiki.osdev.org/Calling_Global_Constructors
+typedef void (*func_ptr)(void);
+
+extern func_ptr _init_array_start[0], _init_array_end[0];
+extern func_ptr _fini_array_start[0], _fini_array_end[0];
+
+void _init(void) {
+    for (func_ptr *func = _init_array_start; func != _init_array_end; func++)
+        (*func)();
+}
+
+void _fini(void) {
+    for (func_ptr *func = _fini_array_start; func != _fini_array_end; func++)
+        (*func)();
+}
+
+func_ptr _init_array_start[0] __attribute__ ((used, section(".init_array"), aligned(sizeof(func_ptr)))) = {};
+func_ptr _fini_array_start[0] __attribute__ ((used, section(".fini_array"), aligned(sizeof(func_ptr)))) = {};

yak-kernel/src/platform/generic/crt/crtn.c

@@ -0,0 +1,7 @@
+//
+// Created by rick on 9-5-23.
+//
+typedef void (*func_ptr)(void);
+
+func_ptr _init_array_end[0] __attribute__ ((used, section(".init_array"), aligned(sizeof(func_ptr)))) = {};
+func_ptr _fini_array_end[0] __attribute__ ((used, section(".fini_array"), aligned(sizeof(func_ptr)))) = {};

yak-kernel/src/rt/kmain.c

@@ -3,6 +3,7 @@
 #include "yak/platform/generic/platform.h"
 
 void kmain() {
+    _init();
     // kmain is called from one of the bootloader implementations
 
     // perform platform specific initialisation
@@ -10,4 +11,5 @@ void kmain() {
 
     // this should (eventually) be unreachable
     panic("End of kmain");
+    _fini();
 }