lib: launch: implement passing args and environment variables to new tasks

lib/liblaunch/stack.h

@@ -0,0 +1,26 @@
+#ifndef LIBLAUNCH_STACK_H_
+#define LIBLAUNCH_STACK_H_
+
+#include <mango/types.h>
+
+struct stack_writer {
+	virt_addr_t w_local_sp;
+	virt_addr_t w_remote_sp;
+};
+
+extern void stack_writer_init(
+	struct stack_writer *w,
+	virt_addr_t local_sp,
+	virt_addr_t remote_sp);
+
+extern void *stack_writer_put_string(
+	struct stack_writer *w,
+	const char *s,
+	virt_addr_t *out_remote);
+extern void *stack_writer_put(
+	struct stack_writer *w,
+	const void *p,
+	size_t len,
+	virt_addr_t *out_remote);
+
+#endif