Can I run Tock apps in a virtual environment?

[saki-osive]

Is it possible to run a Tock app in a virtual environment on Linux (inside a VM, say)? Or having a board is a requirement to do anything at all? Please discuss.

[hudson-ayers]

You can run a Tock app in QEMU. A guide for doing so can be found here: https://github.com/tock/tock/blob/master/doc/Qemu.md

[saki-osive]

Also, could you lead me to a page that directs the user to build the OpenTitan repo so as to be able to have the dynamic ELF files? @alistair23

[alistair23]

It will be at tools/qemu-runner/opentitan-boot-rom.elf

The OpenTitan documentation describes that: https://docs.opentitan.org/doc/ug/getting_started_build_sw/

[saki-osive]

While running the meson_init.sh in the OpenTitan repo, I'm getting the following error. Basically, I'm unable to build it, I think there is/are pre-requisite step(s) missing before the build can be invoked with meson-init.sh. Can I get a full list of dependencies/pre-requisites needed to build this on Ubuntu Server 20.04?

Detected $REPO_TOP at /home/vagrant/opentitan.
Object directory set at /home/vagrant/opentitan/build-out.
Binary directory set at /home/vagrant/opentitan/build-bin.
OpenTitan version: opentitan-earlgrey_silver_release_v5-1547-g37162df49

Output directory already exists at /home/vagrant/opentitan/build-out; skipping.
Set up toolchain file at /home/vagrant/opentitan/build-out/toolchain-configured.txt.
+ meson -Dot_version=opentitan-earlgrey_silver_release_v5-1547-g37162df49 -Dbin_dir=/home/vagrant/opentitan/build-bin -Dkeep_includes=false -Dcoverage=false --cross-file=/home/vagrant/opentitan/build-out/toolchain-configured.txt /home/vagrant/opentitan/build-out
DEPRECATION: c_args in the [properties] section of the machine file is deprecated, use the [built-in options] section.
The Meson build system
Version: 0.59.2
Source dir: /home/vagrant/opentitan
Build dir: /home/vagrant/opentitan/build-out
Build type: cross build
Project name: opentitan
Project version: 0.1

meson.build:5:0: ERROR: Unknown compiler(s): [['/tools/riscv/bin/riscv32-unknown-elf-gcc']]
The following exception(s) were encountered:
Running "/tools/riscv/bin/riscv32-unknown-elf-gcc --version" gave "[Errno 2] No such file or directory: '/tools/riscv/bin/riscv32-unknown-elf-gcc'"

A full log can be found at /home/vagrant/opentitan/build-out/meson-logs/meson-log.txt

@alistair23 Can you please discuss this?

[hudson-ayers]

We don't maintain the OpenTitan repository and are not as familiar with it as the maintainers, so that question is probably better posted on the OpenTitan github

[saki-osive]

That's correct, I just wished to know if the team is familiar with the error for Tock specific use case only, as all we want with OpenTitan for now is the support it provides for Tock.

[lschuermann]

An alternative to QEMU as proposed by @hudson-ayers, which emulates an environment close to a board (e.g. the SiFive HiFive Rev B board), can be a gatelevel-simulation of some hardware. An example for this is the LiteX simulator which takes a hardware description of a chip including a CPU (in Verilog) and uses Verilator to build a simulation for that. Tock's support for this board can be found here: https://github.com/tock/tock/blob/master/boards/litex/sim/README.md. I've set up a companion repository for that which also contains step-by-step instructions on how to get started in setting up your LiteX simulation environment on Ubuntu 20.4 (other Linux distributions should work similarly). Alternatively you can have a look at this pull request, which attempts to create a GitHub actions workflow setting up this environment: #2801.

Please be aware that the LiteX simulation being an accurate simulation of some hardware description means this is quite a bit slower than running a board in QEMU is. It should be sufficient to run some simple apps though.