Dear Sam,
sorry for the delay.
In message 20040504010903.79934.qmail@web15212.mail.bjs.yahoo.com you wrote:
- 64MHz/48MHz system clock options;
If possible, make it automatically detect the clock frequency and auto-adjust. Your users will praise you if the same binary image works on both configurations.
This is really a challenge for me.I meant to build two targets for it and did.How to make it?Usually we set PLPRCR in <board.h> to choose system clock for board init.It seems that it's programmers to decide the value according to CPU max frequency and oscillator's frequency on the board.Any clue with it?
How do you you initialize your HRCW? Again, you can check the TQM8xxL boards to see how to deal with differing clock configurations; you can even allow the user to adjust the clock frequency using the "cpuclk" environment variable.
- ENV_IS_IN_FLASH/ENV_IS_IN_NVRAM;
Either make it a different build targets, or select a standard configuration and let the user decide to modify the board config file.
I really want to make the second possible.Did u-boot command do this job?
I recommend to provide a default configuration which uses environment in flash; you provide the second option (environment in NVRAM) commented out ("# if 0" or so) in the config file, so the user can enable it if he likes so.
Best regards,
Wolfgang Denk