BrunoLevy / learn-fpga

Learning FPGA, yosys, nextpnr, and RISC-V
BSD 3-Clause "New" or "Revised" License
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Which linker script should I be using with the ULX3S? #94

Closed JamesTimothyMeech closed 1 year ago

JamesTimothyMeech commented 1 year ago

With the current version of the repo when I attempt to compile a C program and load it onto the ULX3S the Makefile points to a file that does not exist:

cannot open linker script file /home/james/Desktop/Casino/learn-fpga/FemtoRV/FIRMWARE//CRT/spiflash_ulx3s.ld: No such file or directory

which linker script should I be using with the ULX3S?

BrunoLevy commented 1 year ago

You need to configure the firmware for ULX3S before compiling your C program, as follows:

$ cd learn-fpga/FemtoRV
$ make ULX3S.firware_config 

This will create the file FIRMWARE/config.mk with compilation flags and defines.

Then there are two options to load software on the ULX3S, either use FemtOS, and create .elf binaries stored on the SDCard, more details in the tutorial, or generate .hex files directly incorporated in your design. You can use the Mafile from FIRMWARE/FEMTOS as a starting point for writing your own baremetal software.

JamesTimothyMeech commented 1 year ago

Thanks when I wrote the issue it was not clear to me that I should be loading .elf binaries on an SD card to run them on the ULX3S.