[ELDK] why the dtc in ELDK cannot compiled the mpc8544ds.dts properly?

[林志平]

I am using ELDK4.2 tool chain to boot linux2.6.24 with device tree blob.
I used dtc under ~/ELDK/sbin to compile mpc8544ds.dts

the command I typed are:
#  dtc –I dts –O dtb –V 0x10 –f ./arch/powerpc/boot/dts/mpc8544ds.dts >
mpc8544ds.dtb
DTC: dts->dtb  on file "./arch/powerpc/boot/dts/mpc8544ds.dts"
FATAL ERROR: Reference to non-existent node "mpic"

It seem error exits in mpc8544ds.dts, and only an empty file generated
But when I use the dtc (version 1.0 compiled by myself with the downloaded
source code)

the command I type are:
#  /home/lyn/dtc/dtc -I dts -O dtb -V 0x10 -f
./arch/powerpc/boot/dts/mpc8544ds.dts>mpc8544ds.dtb
DTC: dts->dtb  on file "./arch/powerpc/boot/dts/mpc8544ds.dts"
Warning: physical boot CPU not set.  Use -b option to set

there is only a warning and mpc8544ds.dtb generated, not an empty file.
I am confused about this problem.
why the dtc in ELDK cannot compiled the mpc8544ds.dts properly?
And what is the dtc used for under ~/ELDK/ppc_85xx/sbin, which is a powerpc
format.