P1022, problems running u-boot out of RAM

[caryo_brien]

We have a new P1022 board, and we would like to run u-boot out of ram (DDR) to

debug the flash subsystem.  We're using QorIQ-SDK-V1.6 to build.

I've followed the document in doc/README.ramboot.ramboot-ppc85xx, so

I've got a u-boot.bin linked what seems to be the right way, but I'm having

troouble getting it to run.  I can load it into ram with CW + USB Tap,

and start and step through the code, but it won't run far.

The primary problem is I'm uncertain of the entry point.  When I start

at _start_e500 the init process seems to overwrite the MMU and LAW

buffers supporting access to DDR, and things stop.  Similar problems

starting at _start_cont.  If I setup stack and start from board_init_f, the

there are things not configured, i.e. global data.

Is there a good way to do this without modifying too much code?

Thanks in Advance,

-- cary

[addiyi]

Take a look on this application note, CodeWarrior U-Boot Debugging.

Adrian

[caryo_brien]

This helped a lot.

I also found out that I had to have my setup script use L2TLB 0, LAW 0, and CS0

to setup ddr.  If I used different entries, u-boot would clear them in the startup

process and then fail since it had unmapped it's own code.  And not move

CCSRBAR.

-- cary