François
581028a83d
Real-data testing (3 BSDL-attached FPGAs in an 8-card system) showed undriven over-fires when only one side of a net has a known direction: the driver sits on an un-modelled part (direction Unknown). Require known == net pin count, so "undriven" is concluded only when every pin on the net is modelled. Drops 216 false positives to 0 on the sample system while the genuine JTAG findings remain; the unit test is unaffected (its net is fully modelled). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
essim — system digital twin
Interactive simulator for the inter-card connections inside a system. Built around a domain model of modules → parts → pins / signals → connections, with importers for Mentor Graphics, Altium and ODS pinout sheets, a TUI shell with scripting, snapshots and BFS net analysis.
Status: early work-in-progress.
Quick start
cmake -S . -B build
cmake --build build -j
./build/essim
Inside the shell, type help for the live command list — or read the
auto-generated reference at doc/user/commands.md.
A worked bring-up script is at test/system.essim;
load it with source test/system.essim.
Dependencies
- C++17 compiler and CMake 3.14+.
- System libraries libzip and pugixml — install the development
packages:
- Debian/Ubuntu —
sudo apt install libzip-dev libpugixml-dev - Arch —
sudo pacman -S libzip pugixml - Fedora —
sudo dnf install libzip-devel pugixml-devel
- Debian/Ubuntu —
- Fetched automatically at configure time via
FetchContent(nothing to install): FTXUI v6.1.9 and doctest v2.4.11. - Optional, only for the
doctarget: doxygen and python3.
Tests
./build/essim_tests
# or
ctest --test-dir build
Skip building tests entirely:
cmake -S . -B build -DBUILD_TESTING=OFF
Documentation
doc/user/— user guide, command reference, scripting.doc/api/— auto-generated C++ API reference.DESIGN.md— implementation notes (domain conventions, TUI internals, gotchas).doc/README.md— how the doc pipeline is wired.
Regenerate auto-generated parts after substantive code changes:
cmake --build build --target doc # needs doxygen + python3
Project layout
src/system/ domain model (Module/Part/Pin/Signal, Connection, Transform, …)
src/imports/ Mentor / Altium / ODS netlist importers
src/tui/ FTXUI shell (commands, screens, completion, history)
tests/ doctest suite
doc/ api/ + user/ Markdown trees, Doxyfile.in, gen_api_md.py
test/ sample netlists + system.essim bring-up script
Full layout & rationale in DESIGN.md.
Licence
Copyright (c) 2026 François Dausseur
Licensed under the European Union Public Licence (EUPL), Version 1.2 —
the "Licence". You may not use this work except in compliance with the
Licence. You may obtain a copy of the Licence in the LICENSE
file or at https://joinup.ec.europa.eu/software/page/eupl.
Unless required by applicable law or agreed to in writing, software distributed under the Licence is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the Licence for the specific language governing permissions and limitations under the Licence.
SPDX-License-Identifier: EUPL-1.2