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EDK + XMD

Hi,

Here is my problem.

My memory map is as follows:

ISBRAM : 0xFFFFE000:0xFFFFFFFF SDRAM : = 0xF0000000:0xF1FFFFFF

I download bootloop program with the bitstream. The program I want to execute is linked at 0xF0400000.

Then I open XMD and write following commands:

connect ppc hw -debugdevice cpunr 1 dow sw_projects/dpmain/executable.elf run

This works fine the program starts to run, BUT I always get a machine check error at the start of the program. The PLB_Error is caused when I run dow sw_projects/dpmain/executable.elf, because for whatever reason the processor at this moment tries to read address 0xFFFFFFFC on the PLB bus.

Any ideas, why this is and how it could be removed?

Thanks, e

Reply to
eascheiber
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0xFFFFFFFC is the reset vector, and I thought perhaps there is a problem with mapping this to ISBRAM. (If you are searching for this, you get more results searching for ISOCM.)

Other designs have PLB bram at this address and jump to ISBRAM. But the Xilinx Ultracontroller doesn't use PLB bram.

Looking at xapp575.pdf, however, it looks like they use some trickery to make this work correctly. It is not clear what they do, but it appears they have hard wired the reset vector to the otherwise unused PLB bus.

I would be interested to know if other people have ISBRAM at the top of memory and how it was made to work. I have been thinking about changing my PLB bram to ISBRAM for speed.

Alan Nishioka

Reply to
Alan Nishioka

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