iCE40HX8K-EVB REV-B or REV-B1?

[Gene]

I just got a iCE40HX8K-EVB from Mouser, did I get a REV-B or REV-B1? Looking at the pdf schematics side by side I did not immediately see the difference. Is there some practical difference I should be aware of?

I was able to blink the led, programmed using the 32U4. And I was able to load and run the apple-one project and use PS/2 keyboard and VGA (via iCE40-IO) to play with wozmon. So the board seems to work as far as that goes.

My attempts to run the xv6-riscv-fpga project didn't seem to work. I'm not sure how to debug from here. The apple-one project doesn't use the SRAM chip, as far as I can tell; there is a comment on the schematics about switching a resistor with regard to the SRAM, but I didn't understand the implications of that.

What should I check to get the xv6 project going?

[LubOlimex]

Glad you managed to program it, it is the most important step.

You probably got B1 since we've been making that for a few years now. Quite unlikely Mouser still have left over revision B boards. Anyway, hardware revision changes file was missing from GitHub, and the only change is component U1 was changed from W25Q16BVSSIG(SOIC-8_208mil) to EN25Q16B-104HIP(SOIC-8_208mil). Maybe this will help you confirm the revision.

About the software project, we don't have much experience with that maybe some customer would know more.

[Gene]

My U1 part says ZD25Q16.

[LubOlimex]

Hello,

I looked through the production logs and I can confirm latest batch of boards manufactured have ZD25Q16BTIGT SPI memory. This looks like a miss in the documentation and the schematic. I will add a reminder to the designers to fix it. Thanks for the notice.

From our testing the ZD25Q16BTIGT should behave exactly the same as EN25Q16B-104HIP but let me know if you notice something strange.


Best regards,
Lub/OLIMEX

[Gene]

I did get the xv6-riscv-fpga project working on my device (kudos to Michael Schröder @x653) although I don't know if I have everything exactly right. The usertests program failed with "preempt: fork failed" but the 16 tests before that one did seem to pass.

I did use a newer version of GCC to compile the boot code, kernel, and user space.

$ /opt/riscv/bin/riscv64-unknown-elf-gcc --version
riscv64-unknown-elf-gcc (g646b5650a) 14.2.1 20240919

Using "-march=rv32ia_zicsr -mabi=ilp32".

I will continue to tinker and learn, it's great fun!