In message 20110713105743.0C2C116F12CE@gemini.denx.de Wolfgang Denk wrote:
In my preloader some exception vector were setted to print message. So it seems uboot.bin had some illegal asm code in it.
Are you sure that your preloader analyses the binary image it loads and that it would detect specific assembler code in it? I tend to doubt that.
No, No, No it is impossibe, My preloader just set exception vector and it jump to the message output code, It print out error message when a undef instruction exception occurs.
So what compiler options should be use? I notice some u-boot compile commandline has option '-march=armv4'. Why with this option it is still generate wrong code
Thi sis a strong statement, based on somewhat weak facts. Why are you so sure that there is any "wrong code" being generated? Please show which exact instructions you are talking about.
Because the code raised a 'undef instruction' exception, So I guess some illegal code for arm920(may be legal for other armVs) exist.
I will try to objbump u-boot and analyses it later.