HowTo Linux on Pano Logic G2

Linux on Pano Logic G2

Introduction

This how-to guide is for people who want to run Linux on Pano Logic G2 devices using LiteX BuildEnv.

You will need:

• A PC running Linux natively or in a VM.

• Xilinx ISE with support for the XC6SLX100/XC6SLX150 chip, there are three ways to obtain it (all of them involve a valid Xilinx account):

  • download a VM image from the Xilinx website
  • get the Xilinx ISE for Windows 10 with the free Webpack license
  • get the Xilinx ISE for Linux with a regular (non-free) Xilinx license

  All of these options should come with a valid license for the FPGA part on the Pano Logic G2. Note that a standard Webpack ISE download for Linux will most probably not support this part (please use the VM instead). Note the large download size (e.g. the VM is 6.9 GB).

• JTAG adapter

• USB-UART adapter.

All shell commands in this guide use bash.

Gateware and Firmware

To build Gateware for the board you need to use the pano_logic_g2 platform and the base target of LiteX BuildEnv. On top of that you should use VexRiscv Soft CPU with CPU_VARIANT=linux and BUILD_BUILDROOT=1 exported.

After building the Gateware you can use ./scripts/build-linux.sh to build a custom RootFS and Linux kernel for the board.

That should generate the following files:

• <build_dir>/software/linux/firmware.bin
• <build_dir>/software/linux/riscv32-rootfs.cpio
• <build_dir>/software/linux/rv32.dtb
• <build_dir>/emulator/emulator.bin

Accessing the serial port

To access the serial console and upload the Linux image you will need to use a USB-UART adapter. UART can be accessed via 2 DDC pins on the DVI connector, RX is attached to DDC Data and TX is on DDC Clock.

Loading Linux

You can load files generated by build-linux.sh by creating an image.json file similar to this one:

{
        "build/pano_logic_g2_base_vexriscv.linux/software/linux/firmware.bin": "0xc0000000",
        "build/pano_logic_g2_base_vexriscv.linux/software/linux/riscv32-rootfs.cpio": "0xc0800000",
        "build/pano_logic_g2_base_vexriscv.linux/software/linux/rv32.dtb": "0xc1000000",
        "build/pano_logic_g2_base_vexriscv.linux/emulator/emulator.bin": "0x50000000"
}

And then using lxterm --speed <configured_baud_rate> /dev/ttyUSB0 --images <path_to_created_image_json_file> you should be able to load the Linux kernel and the RootFS image into the DDR memory, and shortly after it finishes uploading, a Linux prompt should appear.