Yet another Pulpissimo (on Zedboard) bring-up thread
#1
Hi,

I don't want to hijack one of the other current threads on getting started with Pulpissimo and my problem does not seem to be related to any of them anyway.
I am trying to get Pulpissimo to run on a Zedboard and would like to ask anybody who successfully done this to share his/her exact git revisions of the various related repositories. I think this might be the cause of my problems.

What (presumably) works:
  1. Synthesis: I was able to synthesize the design and download it to the zedboard. When I do so the hardware sets the LD0 LED.
  2. Compilation: I have built the PULP-SDK and I am able to compile binaries using pulp-rt. So far I have only tested the hello pulp-rt-example.
  3. Debugging: Since I don't have the Digilent JTAG adapter I am using an old Altera USB Blaster attached to the PMOD pins. I have changed the OpenOCD configuration accordingly and are able to connect, load and control execution of the RISC-V core with GDB. On first connect it is stopped at 0x1c008080, i.e. _start.
*However*, when I load and run the application that way, it does not work as expected. If we assume that we can trust the debugger then it seems like it gets stuck in rt_user_alloc(). pt and  size get initialized to 0 and 144 (0x90), respectively. Thus, the function returns to rt_alloc() where it is retried. On the second, try pt gets initialized to 0x4c4b40 because a equals the address of __rt_freq_domains and it tries to get its first_free field which is completely bogus!?

Since rt_event_alloc() uses the result of rt_cluster_id() for the values eventually ending up in rt_user_alloc() I presume this might be one of the problems that changing the core ID has as discussed in https://github.com/pulp-platform/pulpissimo/issues/107

KR
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Yet another Pulpissimo (on Zedboard) bring-up thread - by stefanct - 12-20-2019, 03:58 PM

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