Architectures/RISC-V/Disk images

All about the RISC-V disk images.

Latest image

The stage4 disk image is built cleanly from RPMs with no broken dependencies and only a tiny number of modifications (see below).

https://fedorapeople.org/groups/risc-v/disk-images/

The disk image does not include a bootloader, kernel or emulator.

Booting on Fedora QEMU

Download the vmlinux (kernel) from the same directory. Install the bootloader and QEMU:

# dnf copr enable rjones/riscv
# dnf install riscv-qemu riscv-pk

Boot the disk image:

$ qemu-system-riscv -m 4G -kernel /usr/bin/bbl \
     -append vmlinux \
     -drive file=stage4-disk.img,format=raw -nographic

Booting in other places

You will most likely need to compile your own kernel and/or bootloader. Note that the kernel will need to include many features required by systemd and other parts of Fedora. For suggestions on what to configure, see this file.

Installing extra packages inside the VM

Ordinary DNF works inside the disk image. However you will need to configure it.

Installing packages with a working network

Edit /etc/yum.repos.d/local.repo, uncomment the https baseurl and comment out the file baseurl. DNF should be able to download packages from our public repo.

Installing packages without a working network

Fedora's QEMU does not support networking. Therefore you have to download all the RPMS from https://fedorapeople.org/groups/risc-v/RPMS/ (eg. using a recursive wget or rsync) and copy them into the disk image. Simply placing the whole RPMS directory under /var/tmp will work:

$ guestfish -a stage4-disk.img -m /dev/sda
><fs> copy-in -a stage4-disk.img /your/copy/of/RPMS /var/tmp
><fs> exit

DNF groups

DNF groups should work, eg:

# dnf install @buildsys-build

Note about DNF caching

DNF aggressively caches, even local file repositories. Therefore if you get strange errors about missing packages when the packages are obviously there, do this command first:

# dnf clean all

Using systemd or not using systemd

The disk image boots using systemd as the init system. /init inside the disk image is a symlink to systemd.

You will need a kernel which supports all the features required by systemd. If you want to change how the system boots, you will need to add systemd units.

If you prefer not to use systemd, then modify the disk image:

• Remove the /init symlink.
• Add your own /init shell script (or binary).
• Ensure the /init script is executable.

The /init script needs to remount the root filesystem as rw and a few other things. Look at the code of the Fedora autobuilder for an example.

Power off

If you are using systemd, run:

# poweroff

If you are not using systemd, run:

# sync
# poweroff -f

Sources

https://fedorapeople.org/groups/risc-v/SRPMS/

Fedora sources.

https://github.com/rwmjones/fedora-riscv-kernel

Kernel build scripts, kernel config, and a link to the kernel sources we use.

https://github.com/rwmjones/fedora-riscv-stage4

Scripts used to build the stage4 disk image.

https://github.com/rwmjones/fedora-riscv-stage4/blob/master/stage4-build-init.sh

How the RPMs where installed in the stage4 and subsequent modifications.

https://fedoraproject.org/wiki/Architectures/RISC-V

Links to all other documentation.