With the debug de1_boot.bin I couldn't boot at all, but with the de1_boot.bin from the previous re6b2 release I can now reliably get to the kick screen every time. That may have been what you meant to do anyway!
OK, this is what I think is going on: that debug firmware build divides the SPI clock, so it is not running at full speed. Unfortunately there is a problem that I was sure was going to bite us in the ass someday - the SPI link between the control block and minimig is running on two different, non-aligned clocks, and the SPI bus is not completely properly handled for clock domain crossing. It only (more or less) works if the SPI master is faster - in a certain range - from the slave.
What I did for this last FPGA build is reduce the SRAM controller and control block clock from 100MHz/50MHz to 80MHz/40MHz, as that seemed (from your serial output) as a possible cause of the problems (spurious resets of the control CPU). The default clock of 100MHz actually requires that the SRAM is slightly faster than 100MHz because of the delay from the FPGA core to the IO pins and through the board to the SRAM.
That is why the debug firmware build is not working - since the SPI clock is derived from the ctrl clock, when divided it became less than 7MHz. The not-completely-working clock domain crossing could also be a problem why the OSD isn't working 100% for you for the normal firmware build.
MMrobinsonb5: thanks for reporting the same problems from the atariage forum. Although I can hardly believe it, this could indeed be a faulty SRAM chip (but come on, they have been making the same SRAM for years and years, in an old process technology, they should be close to 0 errors by now!
Perhaps bad waffers, or a small change that wasn't tested ...).
Tobiflexx' builds did use the SRAM, it was used for the HDD buffers if I'm not mistaken. I think it was running at a much lower clock, though - probably 28MHz.
Can you please report any new findings from the atariage forums?
MartinW: I'm not sure what else I can do at the moment, but you could try running the Spectrum core for the DE1 or the cores from atariage to see if any of them has similiar problems. Unfortunately I don't have any experience with any of the mentioned cores. You could also try the default core from Terasic, together with the DE1 control panel - I think there is a SRAM test there.