[Qemu-ppc] Customize QEMU

[Sijia Li]

Hi:

Recently I plan to customize QEMU for my own embedded system. The 
content of customization is to add a new QEMU monitor command, so that I 
can use this command to directly modify the value of specific main 
memory space. I know it's dangerous to directly write in memory. But I 
really need this function. Could you give me some tutorial about memory 
management of QEMU and how to add new QEMU monitor command so that I 
could know how to customize QEMU, eg, which lib I should call in QEMU? 
And BTW, my specific board is ref405ep.

Best Regards
Sijia Li