[U-Boot-Users] Setting up reset on the EP885C
Hello,
I am still trying to get my port of u-boot to the EP885C to run. When I use the Planet Core bootloader on this board it seems to execute from address 0xFC000000 in flash, so I set the text base and monitor base to this value. When I program the binary to the board using a BDM, I can see the u-boot string at 0xFC000000. However, when I try to run from 0xFC000000 or 0xFC000100 I get no display at all, and the BDM reads -TARGET: STOPPED. Also, when I try to just program to flash and then reset the board it seems as if no code is executing.
Can anyone verify that 0xFC000000 is the correct flash location for an EP885C? Also, I am thinking that by resetting the hard reset configuration word, I could force the board to jump to the correct instruction location, but I am at a loss to figure out how to change the hrcw's value. Any help would be greatly appreciated--I can't test to see what works if the code won't even execute.
Thanks in advance, Will Haines
I realize now where I was going wrong. I shouldn't jump to conclusions without running the debugger correctly.
Will
In message loom.20050712T193709-463@post.gmane.org you wrote:
However, when I try to run from 0xFC000000 or 0xFC000100 I get no display at all, and the BDM reads -TARGET: STOPPED. Also, when I try to just program to flash and then reset the board it seems as if no code is executing.
Don't try to run any code from any specific address at all. Let the CPU do what it wants to do. Force a reset, and then just single step in your debugger. I would be surprised if the CPU would not start at either 0x0100 or 0xFFF0100.
Can anyone verify that 0xFC000000 is the correct flash location for an EP885C?
It is as good as any other. You can map the flash basicly everywhere and get a working system.
Also, I am thinking that by resetting the hard reset configuration word, I could
Oops? I cannot parse that. Reset the HRCW? What exactly do you mean?
force the board to jump to the correct instruction location, but I am at a loss to figure out how to change the hrcw's value. Any help would be greatly
The HRCW is something you (resp. your hadrware) applies to the bus at reset. Study the schematics of your hw - this might be as simple as pull-ups or -downs (if your hw is half-broken), or some more sophisticated way to drive a certain value on the bus in this situation. Unless you use some prgrammable device fort his purpose you cannot "reset" the HRCW - and if you can change it, it will take effect only at the next reset. It will definitely not make the CPU "jump to the correct instruction location".
Best regards,
Wolfgang Denk
participants (2)
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Will Haines -
Wolfgang Denk