Implement a very crude busy-wait based select() mechanism for consol input.

--HG--
branch : dtrg-videocore
rename : plat/rpi/include/ack/config.h => plat/rpi/include/sys/select.h
rename : plat/rpi/libsys/time.c => plat/rpi/libsys/select.c

plat/rpi/include/sys/select.h

@@ -0,0 +1,13 @@
+/*
+ * Raspberry Pi support library for the ACK
+ * © 2013 David Given
+ * This file is redistributable under the terms of the 3-clause BSD license.
+ * See the file 'Copying' in the root of the distribution for the full text.
+ */
+
+#ifndef _SYS_SELECT_H
+#define _SYS_SELECT_H
+
+#include <unistd.h>
+
+#endif

plat/rpi/include/unistd.h

@@ -90,4 +90,16 @@ typedef void (*sighandler_t)(int);
 extern sighandler_t signal(int signum, sighandler_t handler);
 extern int raise(int signum);
 
+/* Select */
+
+typedef uint32_t fd_set;
+
+extern int select(int nfds, fd_set *readfds, fd_set *writefds,
+                  fd_set *exceptfds, struct timeval *timeout);
+
+#define FD_ZERO(set) do { *set = 0; } while (0)
+#define FD_SET(fd, set) do { *set |= (1<<fd); } while (0);
+#define FD_CLR(fd, set) do { *set &= ~(1<<fd); } while (0);
+#define FD_ISSET(fd, set) (*set | (1<<fd))
+
 #endif