[Yaffs] How to compile yaffs utils

Hallo!

I have downloaded latest yaffs2 source and want to compile yaffs2 utils.
Make generates some errors:

ln -s ../yaffs_ecc.c yaffs_ecc.c
gcc -c -I/usr/include -I.. -O2 -Wall -DCONFIG_YAFFS_UTIL -Wshadow -Wpointer-arith -Wwrite-strings -Wstrict-prototypes -Wmissing-declarations -Wmissing-prototypes -Wredundant-decls -Wnested-externs -Winline yaffs_ecc.c -o yaffs_ecc.o
yaffs_ecc.c:24:22: error: yportenv.h: No such file or directory
yaffs_ecc.c: In function ‘yaffs_ecc_correct’:
yaffs_ecc.c:201: warning: implicit declaration of function ‘hweight8’
yaffs_ecc.c:201: warning: nested extern declaration of ‘hweight8’
yaffs_ecc.c: In function ‘yaffs_ecc_correct_other’:
yaffs_ecc.c:284: warning: implicit declaration of function ‘hweight32’
yaffs_ecc.c:284: warning: nested extern declaration of ‘hweight32’
make: *** [yaffs_ecc.o] Error 1

Please, help me!

Regards,
Vitaly Stolyarov.