Simon Xin Cheng wrote:
Richard,
Thanks for your suggestions. I tried them, however, the system still hangs when jumping to boot code at 0x7c00.
Right now I suspect that something wrong with loder.s. My question is how to debug loader.s? Thanks again.
The most likely problem is that your shadowing is not working.
Right after loader finishes copying to ram and you have enabled reads to be routed to RAM dump the first few bytes from 0x7c00 and dump them out the seial port and make sure things really got copied to RAM.