[ELDK] linux 2.6.24 hangs after print "Uncompressing Kernel Image ... OK"

[林志平]

I am using ELDK4.1
Uboot1.3.1 can boot linux2.4 kernel successfully.
But when I boot the 2.6.24 kernel, It hangs after print

=> tftpboot 0x2000000 uImage
Trying FCC1 ETHERNET
Using FCC1 ETHERNET device
TFTP from server 10.1.26.128; our IP address is 10.1.0.4
Filename 'uImage_10.14_2'.
Load address: 0x2000000
Loading: #################################################################
         ###################################
done
Bytes transferred = 1461513 (164d09 hex)
=> bootm 0x2000000
## Booting image at 02000000 ...
   Image Name:   Linux-2.6.24.2
   Image Type:   PowerPC Linux Kernel Image (gzip compressed)
   Data Size:    1461449 Bytes =  1.4 MB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum ... OK
   Uncompressing Kernel Image ... OK

and it stops forever

2.6.24 kernel is directly produced by invoke:
make mpc8272_ads_defconfig   (which is in the directory
linux-2.6.24/arch/powerpc/configs/mpc8272_ads_defconfig)
make menuconfig
make

I am using CPU mpc8260

And I wonder, if it is because of the incorrect set of bootargs

setenv bootargs console=ttyCPM0,115200 root=/dev/ram

because 2.6.24 kernel seems use ttyCPM0 instead of ttyS0

is it right?
thanks
I am really confused.