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code hang after loading through gdb

Hi,

I'm trying to do a design with dual ppc on an ml410 board with virtex

  1. I first followed an example given on xilinx website and everything seems to be ok. But after I add only one more uartlite (there is already one in the original design), when I load the code through gdb, the code hang there and don't stop at the breakpoint at the beginning of the main function. What could possibly cause the code hang? Since I didn't touch the software, it has to be hardware problem. I checked the mhs file and made sure the second uart has same parameter as the first one. I'm a newbie in using FPGA and don't know what else I should check. Could anybody give me some direction what I should try? Thanks.
Reply to
xmkong
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Try accessing memory from XMD: mrd mwr

Also, you can perform a "sanity" check on the PPC by using 'rrd' to read all the standard registers. If the same value is "smeared" over all the registers, besides the PC which will always have the lowest 2 bits be 0, then it usually means that the accesses timed out.

I've seen issues with memory not being accessible and that causes the situation you are describing.

-- Mike

Reply to
morphiend

Mike,

Thanks for the help. I checked the register values. They are correct. Also, I tried several memory addresses and they are accessible. After trying to reload several times, I found that sometimes, one processor stopped at the beginning as it should be, but the other processor still failed to do so. Now I'm really lost.

--Cathy

Reply to
xmkong

I found the reason now. In my case, I have several software applications. When I downloaded the bitstream, sometimes pc register doesn't contain correct value. Using GDB to download the elf file of the application I want to run doesn't correct the pc register value and hence the code hang. But downloading the elf file through xmd shell can solve the problem.

Reply to
xmkong

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