如何移植Uboot到自己的板子？这段是Uboot源码readme中给出的大体步骤
If the system board that you have is not listed, then you will need
to port U-Boot to your hardware platform. To do this, follow these
steps:
1. Add a new configuration option for your board to the toplevel
"Makefile" and to the "MAKEALL" script, using the existing
entries as examples. Note that here and at many other places
boards and other names are listed in alphabetical sort order. Please
keep this order.
2. Create a new directory to hold your board specific code. Add any
files you need. In your board directory, you will need at least
the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3. Create a new configuration file "include/configs/<board>.h" for
your board
3. If you're porting U-Boot to a new CPU, then also create a new
directory to hold your CPU specific code. Add any files you need.
4. Run "make <board>_config" with your new name.
5. Type "make", and you should get a working "u-boot.srec" file
to be installed on your target system.
6. Debug and solve any problems that might arise.
[Of course, this last step is much harder than it sounds.]
