1 files changed, 91 insertions, 0 deletions
diff --git a/app/kvm.c b/app/kvm.c
new file mode 100644
index 0000000..3c8a900
--- /dev/null
+++ b/app/kvm.c
@@ -0,0 +1,91 @@
+#include "project.h"
+
+
+static enum
+{
+  STATE_SYNC = 0,
+  STATE_ADDR = 1,
+  STATE_ENDPOINT = 2,
+  STATE_LEN = 3,
+  STATE_DATA = 4,
+} state = STATE_SYNC;
+
+
+static uint8_t buf[16];
+static int addr;
+static int endpoint;
+static unsigned int len;
+static unsigned int ptr;
+
+void
+kvm_dispatch (void)
+{
+#if 0
+  printf
+    ("Addr %d, Write to ep %x, %d bytes %02x %02x %02x %02x ...\r\n",
+     addr, endpoint, len, buf[0], buf[1], buf[2], buf[3]);
+#endif
+
+  if (len)
+    usbd_ep_write_packet (usbd_dev, endpoint, buf, len);
+}
+
+void
+kvm_recv (uint8_t d)
+{
+//  printf ("S%d V0x%02x\r\n", state, d);
+
+  if (state == STATE_ADDR)
+    {
+      addr = d;
+      usart_queue (d - 1);
+      state = STATE_ENDPOINT;
+      return;
+    }
+  else
+    {
+      usart_queue (d);
+    }
+
+
+  switch (state)
+    {
+    case STATE_SYNC:
+      if (d != 0x5a)
+        break;
+      state = STATE_ADDR;
+      break;
+    case STATE_ENDPOINT:
+      endpoint = d;
+      if ((endpoint < 0x81) || (endpoint > 0x83))
+        {
+          state = STATE_SYNC;
+        }
+      else
+        {
+          state = STATE_LEN;
+        }
+      break;
+    case STATE_LEN:
+      len = d;
+      ptr = 0;
+      if (len > sizeof (buf))
+        {
+          state = STATE_SYNC;
+        }
+      else
+        {
+          state = STATE_DATA;
+        }
+      break;
+    case STATE_DATA:
+      buf[ptr++] = d;
+      if (ptr >= len)
+        {
+          if (!addr)
+            kvm_dispatch ();
+          state = STATE_SYNC;
+        }
+      break;
+    }
+}