Implement passing commandline strings

libu/system.c

@@ -39,7 +39,9 @@ int device_do(const char* device_key, int cmd, void* a1, void* a2, void* a3, voi
   return (int)do_syscall(SYS_DEVICE_DO, device_key, cmd, a1, a2, a3, a4);
 }
 
-int exec(const char* volume, const char* path) { return (int)do_syscall(SYS_EXEC, volume, path); }
+int exec(const char* volume, const char* path, const char* cmdline) {
+  return (int)do_syscall(SYS_EXEC, volume, path, cmdline);
+}
 
 int volume_open(const char* volume) { return (int)do_syscall(SYS_VOLUME_OPEN, volume); }
 
@@ -126,3 +128,5 @@ int get_volume_info(struct volume_info* infos, size_t count) {
 int volume_delete(const char* key) { return (int)do_syscall(SYS_VOLUME_DELETE, key); }
 
 int date_time(struct date_time* dt) { return (int)do_syscall(SYS_DATE_TIME, dt); }
+
+const char* get_cmdline(void) { return (const char*)do_syscall(SYS_GET_CMDLINE, 0); }