AI 146184: am: CL 145976 am: CL 145806 Add qemud-version auto-detection logic to android/hw-qemud.c
  Document the supported QEMUD services in known Android systems
  Print "Press F6 to exit trackball mode..." in the window title bar when one
  activates the persistent trackball mode. The actual text depends on your
  key binding configuration.
  Refine the skin directory auto-search paths when an AVD name is not given on the
  command line. This makes the following work correctly:
  tools/emulator -sysdir platforms/android-1.5/images -data foo.img
  Original author: digit
  Merged from: //branches/cupcake/...
  Original author: android-build

Automated import of CL 146184
diff --git a/docs/ANDROID-QEMUD.TXT b/docs/ANDROID-QEMUD.TXT
index 6415a47..1364553 100644
--- a/docs/ANDROID-QEMUD.TXT
+++ b/docs/ANDROID-QEMUD.TXT
@@ -92,7 +92,7 @@
 
         connect:<service>:<id>
 
-      where <service> is the service name, and <id> is a 4-hexchar string
+      where <service> is the service name, and <id> is a 2-hexchar string
       giving the allocated channel index for the client.
 
 
@@ -181,9 +181,19 @@
 implementation code of android/hw-qemud.c
 
 The old scheme also used a serial port to allow the daemon and the emulator
-to communicate. Besides, the same multiplexing protocol was used to pass
-messages through multiple channels. However, several other differences
-exist, best illustrated by the following graphics:
+to communicate. However, the multiplexing protocol swaps the position of
+'channel' and 'length' in the header:
+
+           offset    size    description
+
+               0       4     4-char hex string giving the payload size
+
+               4       2     2-char hex string giving the destination or
+                             source channel
+
+               6       n     the message payload
+
+Several other differences, best illustrated by the following graphics:
 
     emulator <==serial==> qemud <-+--> /dev/socket/qemud_gsm <--> GSM client
                                   |