Hi,
I finally figure out how to compile with the recent release of openwrt (r19501) to make an image for WiFi radio. And I can confirm that mpd 0.15 bring in quite a bit of libraries (glib2 for example), and the compiled image won't fit into the 4MB ROM (the image size is about 3.8MB, but I think anything more than 3.5MB is problem) . So the trick is to go into feeds/packages/sound/mpd directory and replace the makefile with older version of makefile. The makefile contain instruction of how to install source code and dependency of libraries. One can go into dev.openwrt.org to retrieve older version of makefile. For my case, the makefile for mpd-0.13.2.
The compiled image is about 2.5MB and is working nicely as WiFi radio now.
Thought I share in case someone is also trying to compile their own.
