Add hardware buttons, cpu booting, tsec booting.

hwinit/btn.c

@@ -0,0 +1,25 @@
+#include "btn.h"
+#include "i2c.h"
+#include "t210.h"
+
+u32 btn_read()
+{
+	u32 res = 0;
+	if(!(GPIO_6(0x3C) & 0x80))
+		res |= BTN_VOL_DOWN;
+	if(!(GPIO_6(0x3C) & 0x40))
+		res |= BTN_VOL_UP;
+	if(i2c_recv_byte(4, 0x3C, 0x15) & 0x4)
+		res |= BTN_POWER;
+	return res;
+}
+
+u32 btn_wait()
+{
+	u32 res = 0, btn = btn_read();
+	do
+	{
+		res = btn_read();
+	} while (btn == res);
+	return res;
+}