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

lib/liblaunch/stack.c

@@ -0,0 +1,59 @@
+#include "stack.h"
+
+#include <mango/log.h>
+#include <string.h>
+
+void stack_writer_init(
+	struct stack_writer *w,
+	virt_addr_t local_sp,
+	virt_addr_t remote_sp)
+{
+	memset(w, 0x0, sizeof *w);
+
+	w->w_local_sp = local_sp;
+	w->w_remote_sp = remote_sp;
+}
+
+void *stack_writer_put_string(
+	struct stack_writer *w,
+	const char *s,
+	virt_addr_t *out_remote)
+{
+	size_t len = strlen(s);
+
+	w->w_local_sp -= (len + 1);
+	w->w_remote_sp -= (len + 1);
+
+	char *local_ptr = (char *)w->w_local_sp;
+	virt_addr_t remote_ptr = w->w_remote_sp;
+
+	memcpy(local_ptr, s, len);
+	local_ptr[len] = '\0';
+
+	if (out_remote) {
+		*out_remote = remote_ptr;
+	}
+
+	return local_ptr;
+}
+
+void *stack_writer_put(
+	struct stack_writer *w,
+	const void *p,
+	size_t len,
+	virt_addr_t *out_remote)
+{
+	w->w_local_sp -= len;
+	w->w_remote_sp -= len;
+
+	void *local_ptr = (char *)w->w_local_sp;
+	virt_addr_t remote_ptr = w->w_remote_sp;
+
+	memset(local_ptr, 0x0, len);
+
+	if (out_remote) {
+		*out_remote = remote_ptr;
+	}
+
+	return local_ptr;
+}