Hello Gary and others,

I was too much concerned of pointers' contents being NULL.
I am ashamed.

I directed my attention toward if_lan91cxx.c.

I added my coding in if_lan91cxx.c,eth_drv.c,if_ethersubr.c,
so I exchanged them with original CVS current sources.

Result was ng_ether_attach_p==NULL and passed out (*ng_ether_attach_p)(ifp),
in next function as before.

ether_ifattach(ifp, bpf)
 register struct ifnet *ifp;
 int bpf;
{
     |
     |
 if (ng_ether_attach_p != NULL)
  (*ng_ether_attach_p)(ifp);
}

I setted DEBUG=0xFF and stored serial output log.
Although I checked it I couldn't pinpoint suspicious point.
I continue to check it.

As I send you gzip file of it,would you please check it.

Also,I remember one point I changed that I should tell you.
Although I don't know it is related to right now problem.

I changed cdl_option CYGBLD_GLOBAL_CFLAGS to next
           default_value { CYGHWR_HAL_SH_BIGENDIAN ?
"-D_KERNEL -D__ECOS -gdwarf-22 -mb -m3 -Wall -Wpointer-arith -Wstrict-prototypes
 -Winline -Wundef -Woverloaded-virtual -ggdb -O1 -ffunction-sections -fdata-sections
 -fno-rtti -fno-exceptions -fvtable-gc -finit-priority" :
"-D_KERNEL -D__ECOS -ml -m3 -Wall -Wpointer-arith -Wstrict-prototypes -Winline
 -Wundef -Woverloaded-virtual -ggdb -O1 -ffunction-sections -fdata-sections
-fno-rtti -fno-exceptions -fvtable-gc -finit-priority" }
from original.
#original  default_value { CYGHWR_HAL_SH_BIGENDIAN ?
"-mb -m3 -Wall -Wpointer-arith -Wstrict-prototypes -Winline -Wundef -Woverloaded-virtual
 -ggdb -O2 -ffunction-sections -fdata-sections -fno-rtti -fno-exceptions -fvtable-gc
 -finit-priority" :
"-ml -m3 -Wall -Wpointer-arith -Wstrict-prototypes -Winline -Wundef -Woverloaded-virtual
 -ggdb -O2 -ffunction-sections -fdata-sections -fno-rtti -fno-exceptions -fvtable-gc
 -finit-priority" }

I changed optimization level from -O2 to -O1
because when I built on cygwin as it was, there happend many Segmentation
errors.
I perused old mailing lists and found that there is bug in sh-elf-gcc,
and on cygwin -O2 causes above errors whereas less than -O1 causes no error.
So I changed to -O1.

And -gdwarf-22 is for making it readable for ICE(PalmICE).

I look forward your reply.

Thank you in advance.

Masahiro Ariga