Program Arty A7 FPGA to be a RISC-V processor - Part II

 When I started on this journey by following instruction from https://digilent.com/reference/programmable-logic/arty-a7/start, I installed Xilinx Vivado on Windows PC as that is the primary working environment. Then when I started building RISC-v, I realized the instruction is all Linux oriented, so I decided to use WSL2 environment to build. The toolchain was successfully built. "make -f Makefile.e300artydevkit verilog" is also OK. But running into problem with "make -f Makefile.e300artydevkit mcs" runs into problem, as it needs to invoke vivado, which I haven't installed, and do not plan to install it under WSL2, simply because it takes too much disk space, and I'm not sure the sure the GUI would work well under WSL2.

Farther looking into the print out from the make mcs output, turns out it is running this from common.mk:

bit := $(BUILD_DIR)/obj/$(MODEL).bit
$(bit): $(romgen) $(f)
        cd $(BUILD_DIR); vivado \
                -nojournal -mode batch \
                -source $(fpga_common_script_dir)/vivado.tcl \
                -tclargs \
                -top-module "$(MODEL)" \
                -F "$(f)" \
                -ip-vivado-tcls "$(shell find '$(BUILD_DIR)' -name '*.vivado.tcl')" \
                -board "$(BOARD)"


# Build .mcs
mcs := $(BUILD_DIR)/obj/$(MODEL).mcs
$(mcs): $(bit)
        cd $(BUILD_DIR); vivado -nojournal -mode batch -source $(fpga_common_script_dir)/write_cfgmem.tcl -tclargs $(BOARD) $@ $<
So it is possible to utilize the Vivado Windows installation, either still do the make under WSL2, or run the make with GNU shell under Windows (such as Cygwin). 

Approach A: Run make under WSL2, install missing Vivado Linux executable

For Windows Vivado installation, it also include Linux vivado shell script under the bin folder. So would need to add the path to the bin like below:

export PATH=$PATH:/mnt/c/Xilinx/Vivado/2022.1/bin

However, Windows Vivado installation won't have Linux executable installed. Would see error like:

WARNING: /mnt/c/Xilinx/Vivado/2022.1/tps/lnx64/jre11.0.11_9 does not exist.
ERROR: Could not find 64-bit executable.
ERROR: /mnt/c/Xilinx/Vivado/2022.1/bin/unwrapped/lnx64.o/vivado does not exist
So would need to extract these missing binaries from installation package.

Approach B: Run make using Cygwin

My freedom.git was synced to my WSL2 home folder. So first thing is find out the Windows path to it. Information can be found from https://superuser.com/questions/1185033/what-is-the-home-directory-on-windows-subsystem-for-linux. For my WSL2 installed on Windows 11, under %LOCALAPPDATA%\Packages\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState is only a 'ext4.vhdx' file, which likely is a virtual disk file. So the way to access it from Cygwin would be map it as a driver, with command like this: net use U: \\wsl.localhost\Ubuntu

Then from Cygwin, cd U: should change CWD to the root dir of WSL2 Ubuntu. However, the make command might still fail with error like this:

Sourcing tcl script 'C:/Users/$win_user/AppData/Roaming/Xilinx/Vivado/Vivado_init.tcl'
source /cygdrive/u/home/$wsl_user/freedom/fpga-shells/xilinx/common/tcl/vivado.tcl
couldn't read file "/cygdrive/u/home/$wsl_user/freedom/fpga-shells/xilinx/common/tcl/vivado.tcl": no such file or directory

To get around this, I moved the freedom folder to be under /mnt/c, which is the Windows C: drive. And this time, it gave me a new error when running make under Cygwin:

Cannot find a jar file even the file exist. So for now, give up on this, until later have some time. Probably can do that directly from Vivado?

<to be continue: moving to do that on Linux>