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TrLeo42 edited this page Apr 12, 2021 · 8 revisions

Prerequisites

Buildroot

Using a Zynq or an SoCFGPA means dealing with the FPGA part, but also with the CPU part. Thus, before configuring the oscimpDigital environment, the operating system must be configured for the targeted board, including by providing a cross-compiler to build drivers, libraries and userspace applications. See the buildroot page for detailed information about this topic.

Download OscimpDigital

Downloading this repository and its submodules in a single command is achieved with

git clone --recursive https://github.com/oscimp/oscimpDigital.git

which can be split in the following individual commands

git clone https://github.com/oscimp/oscimpDigital.git
cd oscimpDigital
git submodule init
git submodule update

to 1/ clone oscimpDigital and 2/ add submodule contents.

Update

If later the repository is updated, the local copy of the repositories can be updated as well using the following commands

git pull
git submodule update

Configure environment

All environment variable information is provided by the settings.sh.sample bash script. This file provides all used env variables and needs to be tuned according to the local setup.

# define the board being used. Must be adapted to either:
# plutosdr for the Xilinx Zynq-based ADI PlutoSDR board
# redpitaya for the Xilinx Zynq-based 14-bit legacy Red Pitaya board
# redpitaya16 for the new Xilinx Zynq-based 16-bit Red Pitaya board
# de0nansoc for the Altera/Intel Terrasic DE0Nano SoC
export BOARD_NAME=

#define Buildroot location
export BR_DIR=

# define target IP
# 192.168.0.10 for RedPitaya
# 192.168.2.1 for PlutoSDR
export IP=

#only mandatory for plutosdr
#export ADI_HDL_DIR=

# define where to install apps, drivers, etc
export OSCIMP_DIGITAL_NFS=/nfs

OSCIMP_DIGITAL=$(cd `dirname "${BASH_SOURCE[0]}"` && pwd)
source $OSCIMP_DIGITAL/app/setenv.sh        # defines $OSCIMP_DIGITAL_APP
source $OSCIMP_DIGITAL/fpga_ip/setenv.sh    # defines OSCIMP_DIGITAL_IP
source $OSCIMP_DIGITAL/lib/setenv.sh        # OSCIMP_DIGITAL_LIB
source $OSCIMP_DIGITAL/linux_driver/setenv.sh

export PATH=$PATH:$OSCIMP_DIGITAL_APP/tools/module_generator:$OSCIMP_DIGITAL_IP/tools/

# /!\ locale settings for Vivado (uses '.' as separator, as opposed to the French ',')
export LANG=en_US.UTF-8
# /!\ check /etc/locale.gen: en_US.UTF-8 UTF-8 must be UNcommented. If it was commented:
#     remove comment and execute as root locale-gen

We recommend you to make a copy of this file and name it settings.sh and to modify this file instead of the settings.sh.sample to keep the empty file in case you need to make a new configuration.

Most important information are:

  • BOARD_NAME used to determine target board and adapt the behavior of Makefiles
  • BR_DIR variable provides the path to the buildroot directory. Mandatory to build drivers, library and userspace applications.

Additional variables are less important but must defined:

  • NFS_DIR: a solution to share bitstream and binaries, is to use NFS (Network File System. By using this variable, a directory located on the host system (personal computer) will be shared with the target (embedded) board. This directory (and sub-directories) will be available from your target platform.

For example for the Redpitaya STEM-125 14 board, the sample file is copied as settings.sh in the oscimpDigital/ directory and filled with relevant information:

BOARD_NAME='redpitaya'

BR_DIR=~/git/buildroot-2020.11.1/

resulting in the following settings.sh file:

export BOARD_NAME='redpitaya'
export BR_DIR='~/git/buildroot-2020.11.1'
export IP=192.168.0.10
export OSCIMP_DIGITAL_NFS='/nfs'

OSCIMP_DIGITAL=$(cd `dirname "${BASH_SOURCE[0]}"` && pwd)
source $OSCIMP_DIGITAL/app/setenv.sh        # defines $OSCIMP_DIGITAL_APP
source $OSCIMP_DIGITAL/fpga_ip/setenv.sh    # defines OSCIMP_DIGITAL_IP
source $OSCIMP_DIGITAL/lib/setenv.sh        # OSCIMP_DIGITAL_LIB
source $OSCIMP_DIGITAL/linux_driver/setenv.sh

export PATH=$PATH:$OSCIMP_DIGITAL_APP/tools/module_generator:$OSCIMP_DIGITAL_IP/tools/

# /!\ locale settings for Vivado (uses '.' as separator, as opposed to the French ',')
export LANG=en_US.UTF-8
# /!\ check /etc/locale.gen: en_US.UTF-8 UTF-8 must be UNcommented. If it was commented:
#     remove comment and execute as root locale-gen

Make sure to always source this file every time and in each terminal you want to use OscimpDigital in, to load the variables in your shell :

source oscimpDigital/settings.sh

library

Libraries must be compiled after cloning the repository or updating the local copy. Go to the lib sub-directory to build libraries with :

cd lib
make

Two files are now added to the directory, one with a .so extension, the other with a .a extension

There are two solutions to install/reinstall libraries :

  • before SD card flash

Run this command in the oscimpDigital/lib/ directory :

make install

Then, in the buildroot root directory re-run make to update the sdcard.img and flash the disk image on the SD card.

  • at runtime

First, make sure you can access to the target board from the host computer through ssh. Then run the command :

make install_ssh

It will ask for the root password of the target board (root by default), and then it will copy the .so file in the /usr/lib/ directory of the target board.

drivers

As for libraries, you need to have all required shell variables. Ensure that you used the source settings.sh with the terminal you are using. Then, we will have to make sure the buildroot toolchain path is included in your $PATH. If not,

export PATH=/somewhere/output/host/usr/bin:$PATH

where somewhere is the location of the buildroot, installed as described at https://github.com/trabucayre/redpitaya.

Then go in the linux_driver directory :

cd linux_driver

And execute :

make install_nfsdir

This command will build all drivers and install them in directory called modules below the directory defined by $OSCIMP_DIGITAL_NFS/$BOARD_NAME.

module_generator

module_generator is a necessary tool to handle the CPU part of a project (see gettingStarted for example). This tool is available in oscimpDigital/app/tools/module_generator. In order to build it, make sure that the dependencies specified in the README of the module are installed on your system, then go into the directory oscimpDigital/app/tools/module_generator and run make install to build it. More information on how to build it can be found in the README.

Finalize the configuration of the host computer

Console (command line interface) access to the board can be granted through a serial port or by using ssh:

  • for the first case a tool like minicom, screen or kermit must be installed on the host computer
  • for the second case openssh must be installed on the host computer

The default way to access bistreams, applications and drivers is through a NFS (Network File System) shared directory. First nfs-kernel-server must be installed on the host computer.

As root, run :

apt install nfs-kernel-server nfs-common
mkdir /nfs

To have right access to /nfs and subdirectories owner must be changed (as root):

chown -R $(id -u).$(id -g) /nfs

Then /etc/exports must be configured to allow for the /nfs directory to be mounted on the remote board with something like

/nfs *(rw,no_root_squash,sync,no_subtree_check)

This configuration will allow any remote computer to mount the host /nfs. The NFS configuration can be tailored to a more secure configuration with

/nfs	192.168.0.10(rw,no_root_squash,sync)

for a single target. Alternatively, a range of ip can be given acces to your nfs server with a netmask:

/nfs    192.168.0.10/255.255.255.0(rw,no_root_squash,sync)

On the target board, mounting the host /nfs directory is automated with by adding at the end of the /etc/fstab file of the board OS (assuming that the host computer IP address is 192.168.0.1):

192.168.0.1:/nfs /usr/local nfs defaults,noauto,nolock 0  0

or by uncommenting this line which already exists on the Redpitaya Buildroot overlay. Thanks to such a configuration, mounting the NFS directory on the target board can be done by running this command on the target board :

mount /usr/local
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