This guide explains how to produce a linux kernel and boot it on CVA6 on a Genesys 2 board. It uses the CVA6 SDK repository and follows the instructions given there.
To build a linux image, first clone the CVA6 SDK repository, cd into it and clone all submodules:
git clone https://github.com/openhwgroup/cva6-sdk.git
cd cva6-sdk
git submodule update --init --recursive
and install the following required packages:
sudo apt install autoconf automake autotools-dev curl libmpc-dev libmpfr-dev libgmp-dev libusb-1.0-0-dev gawk build-essential bison flex texinfo gperf libtool patchutils bc zlib1g-dev device-tree-compiler pkg-config libexpat-dev
You can then build the SBI firmware and the Linux image with the following command:
make images
Once the SBI firmware and Linux image built, you have to write them to an SD card which will let CVA6 boot linux once inserted in the Genesys 2 board.
The CVA6 SDK Makefile offers the flash-sdcard target which uses the SDDEVICE environment variable to specify the device to write to.
Assuming your SD card shows as /dev/sdb on your system and that you need root privileges to access it, you will need to run the make command with elevated privileges.
Using sudo will allow access but will need to be called with the -E flag which will take care to preserve the calling environment (and the SDDEVICE variable in particular!).
Run the following command (adapting /dev/sdb to your needs) to write the SD card:
sudo -E make flash-sdcard SDDEVICE=/dev/sdb
Prepare a Genesys 2 board with a CVA6 image (as explained here).
Insert the SD card written with the SBI firmware and the Linux image in the Genesys 2 board.
Connect to the serial port, using picocom or screen for example (as suggeseted in the CVA6 repository).
screen /dev/ttyUSB0 115200
You can also use PlatformIO serial connection directly if using a PlatformIO flow.
Finally, turn on the Genesys 2 board and should be able to sede bootloader messages followed by Linux kernel messages, and eventually reach a root prompt.