initd: implement simple test init daemon

CMakeLists.txt

@@ -71,7 +71,7 @@ configure_file(
 
 add_subdirectory(arch)
 
-#add_subdirectory(init)
+add_subdirectory(init)
 add_subdirectory(kernel)
 add_subdirectory(lib)
 
@@ -86,7 +86,7 @@ add_custom_command(
 	COMMAND ${CMAKE_LINKER}
 	ARGS ${ARDIX_LINKER_FLAGS} -o ardix.elf
 		$<TARGET_FILE:ardix_arch>
-		#$<TARGET_FILE:ardix_init>
+		$<TARGET_FILE:ardix_init>
 		$<TARGET_FILE:ardix_kernel>
 		$<TARGET_FILE:ardix_kernel_fs>
 		$<TARGET_FILE:ardix_lib>

init/main.c

@@ -0,0 +1,52 @@
+/* See the end of this file for copyright, license, and warranty information. */
+
+#include <ardix/io.h>
+#include <ardix/kent.h>
+#include <ardix/kevent.h>
+#include <ardix/sched.h>
+
+#include <config.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+
+int child_test(void)
+{
+	printf("[child ] i'm so sleempy,, calling sleep(),,\n");
+	sleep(1000);
+	printf("[child ] sleep() returned, i'm gonna kill myself now uwu\n");
+	return 69;
+}
+
+/**
+ * @brief init daemon entry point.
+ */
+int init_main(void)
+{
+	printf("[parent] calling exec()\n");
+	pid_t pid = exec(child_test);
+	printf("[parent] exec() returned, child pid = %d\n", pid);
+
+	int status;
+	printf("[parent] calling waitpid()\n");
+	waitpid(-1, &status, 0);
+	printf("[parent] waitpid() returned, child exit code = %d\n", status);
+	printf("[parent] my child has died, goodbye cruel world qwq\n");
+
+	return 0;
+}
+
+/*
+ * This file is part of Ardix.
+ * Copyright (c) 2020, 2021 Felix Kopp <owo@fef.moe>.
+ *
+ * Ardix is non-violent software: you may only use, redistribute,
+ * and/or modify it under the terms of the CNPLv6+ as found in
+ * the LICENSE file in the source code root directory or at
+ * <https://git.pixie.town/thufie/CNPL>.
+ *
+ * Ardix comes with ABSOLUTELY NO WARRANTY, to the extent
+ * permitted by applicable law.  See the CNPLv6+ for details.
+ */

kernel/main.c

@@ -12,6 +12,8 @@
 #include <stdio.h>
 #include <unistd.h>
 
+extern int init_main(void); /* init/main.c */
+
 /**
  * Core init routine.
  *
@@ -44,9 +46,10 @@ int main(void)
 	printf("This is non-violent software, and there is NO WARRANTY.\n");
 	printf("See <https://git.fef.moe/fef/ardix> for details.\n\n");
 
-	/* TODO: The next big step is to write initd and fork to it here. */
-	while (1)
-		sleep(1000);
+	pid_t pid = exec(init_main);
+	waitpid(pid, &err, 0);
+	printf("initd exited with status %d, system halted\n", err);
+	while (1);
 }
 
 /*