kernel: implement initcalls and a testing system

arch/x86_64/initcall.c

@@ -0,0 +1,41 @@
+#include <socks/init.h>
+
+extern char __initcall0_start[];
+extern char __initcall1_start[];
+extern char __initcall2_start[];
+extern char __initcall3_start[];
+extern char __initcall4_start[];
+extern char __initcall5_start[];
+extern char __initcall6_start[];
+extern char __initcall7_start[];
+extern char __initcall8_start[];
+extern char __initcall_end[];
+
+static initcall_t *m_init_func_levels[] = {
+    (initcall_t *)__initcall0_start,
+    (initcall_t *)__initcall1_start,
+    (initcall_t *)__initcall2_start,
+    (initcall_t *)__initcall3_start,
+    (initcall_t *)__initcall4_start,
+    (initcall_t *)__initcall5_start,
+    (initcall_t *)__initcall6_start,
+    (initcall_t *)__initcall7_start,
+    (initcall_t *)__initcall8_start,
+    (initcall_t *)__initcall_end,
+};
+
+int start_initlevel(int level) {
+    if (m_init_func_levels[level] == m_init_func_levels[level + 1]) {
+        return 0;
+    }
+
+    for (initcall_t *fn = m_init_func_levels[level]; fn < m_init_func_levels[level + 1]; fn++) {
+	    int res = (*fn)();
+
+	    if (res != 0) {
+		    return res;
+	    }
+    }
+
+    return 0;
+}