Hi Charles,
please ignore the previous patch which was not complete for linux 
compilation.
I splitted it and did some more modifications:

1. Minor fixes:
- some inlines
- extern "C" to include yaffsfs.h from C++
- u32/unsigned type mismatch in yaffs_query_init_block_state() prototype
- int yaffsfs_GetLastError(void) should be defined is yaffs_osglue.h
- struct yaffsfs_DeviceConfiguration no longer needed in yaffscfg.h
- remove invalid state value in trace message in yaffs2_checkpt_find_block()
- some redundant includes in yaffsfs.c

2. string functions macros with yaffs_ prefix

3. Patch for more customization of ydirectenv.h from user defined 
configuration in yaffscg.h, and remove debug functions

-- 
Stephane Lesage