Tame the (Q)emu - SSTIC 2024

Introduction

This repository is based on QEMU 8.2 stable branch and adds support for a custom board based on a Microchip ATSAMD21G18A microcontroller (MCU) with heavily documented source code. The goal of this project is to provide an example of implementation of a new MCU and its dedicated peripherals, as well as a specific electronic board with external components.

This project is part of a short talk given at the French Symposium sur la Sécurité des Technologies de l'Information et de Communication event in 2024. Slides, video recording and article (PDF) of this talk are available on the talk's dedicated page (slides and article in English, talk in French). The article is also available in this repository.

Files added by our implementation

• qemu/hw/arm/samd21.c
• qemu/hw/arm/qblilboard.c
• qemu/hw/gpio/samd21_gpio.c
• qemu/hw/misc/samd21_sercom.c
• qemu/include/hw/samd21_mcu.h
• qemu/include/hw/samd21.h
• qemu/include/gpio/samd21_gpio.h
• `qemu/include/misc/samd21_sercom.qemu

Building QEMU to emulate our custom board

$ cd qemu
$ mkdir build
$ cd build
$ ../configure --target-list=arm-softmmu
$ make

Running the example firmware

$ cd qemu/build/
$ ./qemu-system-arm -M qb-lilboard --kernel ../../firmware/QemuTest.bin -drive file=../../firmware/flash.bin,if=none,format=raw -serial stdio

Important note

This repository being part of a tutorial published in the context of a conference, the provided code will not be maintained and is given as an example implementation compatible with QEMU version 8.2. It will not be updated/adapted to any future version of QEMU and will not reflect the future changes that may occur in QEMU's API.

Nevertheless, QEMU basic principles (QEMU Object Model, memory management, GPIO and IRQs) are not expected to change a lot in future QEMU development.