SiFive Freedom Unleashed SDK

The new experimental Freedom Unleashed (FU) SDK is based on OpenEmbedded (OE). It's a minimal meta-sifive layer on top of meta-riscv to provide additional modifications and new disk image targets. Using OE you will be able to:

• build predefined disk images for QEMU and SiFive HiFive Unleashed development board (incl. HiFive Unleashed Expansion Board from Microsemi);
• build custom disk images with additional software packages from various third-party OE layers;
• quickly launch QEMU VM instance with your built disk image;
• build bootloader binaries (OpenSBI, U-Boot, U-Boot SPL);
• build Device Tree Binary (DTB);
• build Linux kernel images;
• easily modify disk partition layout.

Berkeley Boot Loader (BBL) is replaced by OpenSBI and uSD (microSD) disk images now also incl. FSBL (U-Boot SPL).

For more information on particular release see

ReleaseNotes

The old SDK based on Buildroot is archived in

archive/buildroot

For advanced OE usage we advice to look into the following third-party manuals:

• BitBake User Manual 3.1.2 by Yocto

• Yocto Project Reference Manual 3.1.2 by Yocto

• Yocto Project Complete Documentation (MegaManual) Set 3.1.2 by Yocto

• A practical guide to BitBake by Harald Achitz

Quick Start

Install

repo

Then install a number of packages for BitBake (OE build tool) to work properly on your host system. BitBake itself depends on Python 3. Once you have Python 3 installed BitBake should be able to tell you most of the missing packages.

For Ubuntu 18.04 (or newer) install python3-distutils package.

Detailed instructions for various distributions can be found in "Required Packages for the Build Host" section in Yocto Project Reference Manual.

Creating Workspace

This needs to be done every time you want a clean setup based on the latest layers.

mkdir riscv-sifive && cd riscv-sifive
repo init -u git://github.com/sifive/meta-sifive -b 2020.09 -m tools/manifests/sifive.xml
repo sync

Creating a Working Branch

If you want to make modifications to existing layers then creating working branches in all repositories is advisable.

repo start work --all

Updating Existing Workspace

If you want to pull in the latest changes in all layers.

cd riscv-sifive
repo sync
repo rebase

Getting Build Tools (optional)

OpenEmbedded-Core requires GCC 6 or newer to be available on the host system. Your host system might have an older version of GCC if you use LTS (Long Term Support) Linux distribution (e.g. Ubuntu 16.04.6 has GCC 5.4.0). You could solve this issue by installing build tools. This requires less than 400MB of disk space. You can download pre-built one or build your own build tools.

Option 1: Installing OpenEmbedded-Core Build Tools (Pre-Built)

$BUILDDIR/../openembedded-core/scripts/install-buildtools

The native SDK will be installed under

$BUILDDIR/../openembedded-core/buildtools

Finally you should be able to use build tools:

. $BUILDDIR/../openembedded-core/buildtools/environment-setup-x86_64-pokysdk-linux

Option 2: Building Your Own Build Tools

Your host needs to have GCC 6 (or newer) or build tools installed from Option 1.

You can find pre-built tools from the same release source in GitHub release assets.

To build your own build tools execute the command below:

bitbake buildtools-extended-tarball

You can find the native SDK under

$BUILDDIR/tmp-glibc/deploy/sdk/

Now you can install build tools:

$BUILDDIR/tmp-glibc/deploy/sdk/x86_64-buildtools-extended-nativesdk-standalone-nodistro.0.sh -d $BUILDDIR/../openembedded-core/buildtools -y

Finally you should be able to use your build tools:

. $BUILDDIR/../openembedded-core/buildtools/environment-setup-x86_64-oesdk-linux

Setting up Build Environment

This step has to be done after you modify your environment with toolchain you want to use otherwise wrong host tools might be available in the package build environment. For example,

gcc

*-native

. ./meta-sifive/setup.sh

You can verify and fix your host tools by checking symlinks in

$BUILDDIR/tmp-glibc/hosttools

directory.

Configuring BitBake Parallel Number of Tasks/Jobs

There are 3 variables that control the number of parallel tasks/jobs BitBake will use:

BB_NUMBER_PARSE_THREADS

BB_NUMBER_THREADS

PARALLEL_MAKE

$BUILDDIR/conf/local.conf

MACHINE

PARALLEL_MAKE="-j 4" BB_NUMBER_THREADS=4 MACHINE=freedom-u540 bitbake demo-coreip-cli

Leaving defaults could cause high load averages, high memory usage, high IO wait and could make your system unresponsive due to resources overuse. The defaults should be changed based on your system configuration.

Building Disk Images

There are two disk image targets added by meta-sifive layer:

• demo-coreip-cli

  - basic command line image (recommended);

• demo-coreip-xfce4

  - basic graphical disk image with Xfce 4 desktop environment (requires HiFive Unleashed Expansion Board with supported GPUs, for example, Radeon HD 6450 or Radeon HD 5450).

By default disk images do not include debug packages. If you want to produce disk images with debug packages append

-debug

demo-coreip-cli-debug

There are two machine targets currently tested:

• qemuriscv64

  - RISC-V 64-bit (RV64GC) for QEMU virt machine;

• freedom-u540

  - SiFive HiFive Unleashed development board with or without HiFive Unleashed Expansion Board from Microsemi.

It's not possible to use disk images built for

freedom-u540

with QEMU 4.0 and instructions provided below.

Building disk images is CPU intensive, requires <10GB of sources downloaded over the Internet and <110GB of local storage.

Building disk image takes a single command which may take anything from 30 minutes to several hours depending on your hardware. Examples:

MACHINE=qemuriscv64 bitbake demo-coreip-cli
MACHINE=freedom-u540 bitbake demo-coreip-cli
MACHINE=freedom-u540 bitbake demo-coreip-xfce4

Running in QEMU

OE provides easy to use wrapper for QEMU:

MACHINE=qemuriscv64 runqemu nographic slirp

Running on Hardware

You will find all available build fragments (incl. disk images) in

$BUILDDIR/tmp-glibc/deploy/images/$MACHINE

MACHINE

freedom-u540

Disk images files use

-.

demo-coreip-cli-freedom-u540.wic.xz

.wic.xz

Be very careful while picking /dev/sdX device! Look at dmesg, lsblk, blkid, GNOME Disks, etc. before and after plugging in your uSD card to find a proper device. Double check it to avoid overwriting any of system disks/partitions!

Unmount any mounted partitions from uSD card before writing!

We advice to use 16GB or 32GB uSD cards. 8GB cards (shipped with HiFive Unleashed) can still be used with

demo-coreip-cli

CLI images.

Finally write uSD card:

xzcat demo-coreip-cli-freedom-u540.wic.xz | sudo dd of=/dev/sdX bs=512K iflag=fullblock oflag=direct conv=fsync status=progress

You will need to modify MSEL to allow using FSBL and OpenSBI + U-Boot bootloaders from uSD card instead of SPI-NOR Flash chip:

      USB   LED    Mode Select                  Ethernet
 +===|___|==****==+-+-+-+-+-+-+=================|******|===+
 |                | | | | |X| |                 |      |   |
 |                | | | | | | |                 |      |   |
 |        HFXSEL->|X|X|X|X| |X|                 |______|   |
 |                +-+-+-+-+-+-+                            |
 |        RTCSEL-----/ 0 1 2 3 
You can login with 
root
 account. The password is 
sifive
.

Connecting Using Serial Console

Connect your HiFive Unleashed to your PC using microUSB-USB cable to access serial console.

For macOS, run: 
screen -L /dev/tty.usbserial-*01 115200

For Linux, run: 
screen -L /dev/serial/by-id/usb-FTDI_Dual_RS232-HS-if01-port0 115200

The above commands might vary depending on your exact setup.

-L
 command will log all output to 
screenlog.0
 in your current working directory.

To quit screen, hit 
Ctrl - A
 followed by 
\
 symbol. Finally agree to terminate all windows by typing 
y
.

Connecting Using SSH

SSH daemon is started automatically.

The HiFive Unleashed behaves like any other network capable device (such as PC, laptop, and Single Board Computers like Raspberry Pi). Connect your HiFive Unleashed to your network (e.g. a router) and it will acquire IPv4 + DNS configuration using DHCP protocol. You can use your router management panel to get assigned IPv4 address or use the serial console to acquire it directly from the HiFive Unleashed (use 
ip addr
 command to print active network information). Finally you can SSH to the machine:
ssh -o PreferredAuthentications=password -o PubkeyAuthentication=no -o StrictHostKeyChecking=no -o "UserKnownHostsFile /dev/null" [email protected]

Supported GPUs

CAICOS family of GPUs from AMD were supported from the beginning and thus are the most tested. In particular Radeon HD 6450 is the most widely used and is highly recommended today. Other GPUs from the same family might also work. That could be: HD64xxM, HD7450, HD8450, R5 230, R5 235, R5 235X

This was extend to support newer AMD GPUs, but only POLARIS12 based RX 550 was tested so far.

Online Resizing of rootfs (Root File Partition)

It is highly advised to resize partitions offline (i.e. before booting the system). If you already booted the system and cannot do offline resizing then the following instructions should resize rootfs (root file partition) to full uSD capacity:
sgdisk -v /dev/mmcblk0
sgdisk -e /dev/mmcblk0
parted /dev/mmcblk0 resizepart 4 100%
resize2fs /dev/mmcblk0p4
sync

Contributions & Feedback

If you want to file issues, send patches and make feature/enhancement requests use meta-sifive or freedom-u-sdk repositories on GitHub.

You are also welcome to join SiFive Forums  there we have HiFive Unleashed category for discussions.

Known Issues


Avoid overclocking SOC using CPUFreq if you are using HiFive Unleashed Expansion Board from Microsemi as this will hang the board. Hard reset will be required.
If Xfce4 desktop disk image is used with HiFive Unleashed Expansion Board and GPU then rebooting is required after the 1st boot.
OpenEmbedded Core (and thus meta-sifive) does not support eCryptFS or any other file system without long file names support. File systems must support filenames up to 200 characters in length.

BitBake requires UTF-8 based locale (e.g. 
en_US.UTF-8
). You can choose any locale as long as it is UTF-8. This usually happens in containers (e.g. ubuntu:18.04). You can verify your locale by running 
locale
 command. On Ubuntu 18.04 you can change locale following these instructions:

   apt update
   apt install locales
   locale-gen en_US.UTF-8
   update-locale LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8
   export LANG="en_US.UTF-8"
   locale

You can change system default locale with 
dpkg-reconfigure locales
 command.