[U-Boot-Users] about the system clock config

wang cheng wangcheng at rails.com.cn
Sat Nov 1 16:32:06 CET 2003

Dear Wolfgang Denk:
    I have configed my WindRiver mdppro8xx board 

according to the  TQM8xxL module.The outcome is :
U-Boot 0.4.8 (Oct 31 2003 - 15:47:15)

CPU:   XPC823xxZTnnB2 at 25 MHz: 2 kB I-Cache 1 kB 

Board: WindRiver mdppro8xx
DRAM:  16 MB
before relocate_code()
Now I want to set my system clock to 50MHz.

In the TQM8XXL.h there are clauses like these:
"#if   defined(CONFIG_80MHz)
 #elif defined(CONFIG_66MHz)
 #else		/*   50 MHz */
 so I added these:#define CONFIG_80/66/50MHz,but the 

outcome are still :
CPU:   XPC823xxZTnnB2 at 25 MHz: 2 kB I-Cache 1 kB 

Why  did my #define CONFIG_80/66/50MHz not work?
The gd->cpu_clk is evaluated in cpu/mpc8xx/speed.c by 

gd->cpu_clk = measure_gclk();but the function 

measure_gclk() seems have nothing to do with my 

board.h,right? So where to modify my system clock to 


I have a vxWorks BSP of my WindRiver MDP8xx pro 

board.Everything is OK in vxWorks enviroment,now I 

want to run linux on it so the first thing is to port 

 u-boot to it.I have modified the system_clock 

registers like SCCR/PLPRCR according to the romINIT.s 

in vxworks bsp,but there are nothing outcome in the 


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