LTZVisor

Introduction

LTZVisor is a lightweight TrustZone-assisted hypervisor. It allows the consolidation of two virtual machines (VMs), running each of them in an independent virtual world (secure and non-secure) supported by TrustZone-enabled processors. The secure world is tipically used for running a small TCB size VM, while the non-secure world is used for running a rich environment.

For the Cortex-A series a tipical configuration encompasses running a RTOS as secure VM and a GPOS as non-secure VM. For the new generation Cortex-M microcontrollers it can be used for running a bare metal application or a lightweight RTOS as secure VM side by side with a RTOS or an embedded OS for IoT as non-secure VM.

NOTE: This is work in progress! Don't expect things to be complete. Use at your own risk.

Community Resources

Project website:

• http://www.tzvisor.org/

Project home:

• https://github.com/tzvisor

LTZVisor source code:

• https://github.com/tzvisor/ltzvisor

Mailing list:

• ltzvisor-dev@googlegroups.com

Frequently Asked Questions (FAQ):

• Please see FAQ file

Contributing:

• Please see Contribution file

Hardware requirements

LTZVisor is limited by design to TrustZone-enabled ARM processors, which include all Cortex-A series (ARMv7-A and ARMv8-A) and the new generation Cortex-M series (ARMv8-M):

• ARM Cortex-A5 (ARMv7-A)

• ARM Cortex-A7 (ARMv7-A)

• ARM Cortex-A8 (ARMv7-A)

• ARM Cortex-A9 (ARMv7-A)

• ARM Cortex-A15 (ARMv7-A)

• ARM Cortex-A17 (ARMv7-A)

• ARM Cortex-A32 (ARMv8-A)

• ARM Cortex-A35 (ARMv8-A)

• ARM Cortex-A53 (ARMv8-A)

• ARM Cortex-A57 (ARMv8-A)

• ARM Cortex-A72 (ARMv8-A)

• ARM Cortex-A73 (ARMv8-A)

• ARM Cortex-M23 (ARMv8-M)

• ARM Cortex-M33 (ARMv8-M)

LTZVisor has support for the following boards:

• ARMv7-A

  • Xilinx Zynq-7000 All Programmable SoC ZC702 Evaluation Kit
  • ZedBoard Zynq-7000 ARM/FPGA SoC Development Board
  • Zybo Zynq-7000 ARM/FPGA SoC Trainer Board
  • PYNQ-Z1 Python Productivity for Zynq (on going)
  • i.MX 6QuadPlus SABRE Development Board (on going)

• ARMv8-A

  • Xilinx Zynq UltraScale+ MPSoC ZCU102 Evaluation Kit (on going)

Software requirements

For building LTZVisor a host system should exist. The host system must be endowed with an Operating Systems supporting a compilation toolchain. We strongly recommend the use of Linaro GNU Toolchain:

• Ubuntu 12.04 and Linaro GNU Toolchain (7.1.1-2017.08)
  • arm-eabi-gcc 7.1.1
  • arm-eabi-as 2.28.2
  • arm-none-eabi-ld 2.28.2
  • arm-none-eabi-objcopy 2.28.2

Download: https://releases.linaro.org/components/toolchain/binaries/7.1-2017.08/arm-eabi/

LTZVisor was also tested under the following host configurations:

• Ubuntu 12.04 and Sourcery G++ Lite Toolchain (2011.03-42)
  • arm-none-eabi-gcc 4.5.2
  • arm-none-eabi-as 2.20.51
  • arm-none-eabi-ld 2.20.51
  • arm-none-eabi-objcopy 2.20.51

For Xilinx-based platforms LTZVisor was also tested under the following host configurations:

• Ubuntu 12.04 and Sourcery CodeBench Lite Toolchain (2012.09-105)

  • arm-xilinx-eabi-gcc 4.7.2
  • arm-xilinx-eabi-as 2.23.51
  • arm-xilinx-eabi-ld 2.23.51
  • arm-xilinx-eabi-objcopy 2.23.51

• Windows 10 and Sourcery CodeBench Lite Toolchain (2015.05-16)

  • arm-xilinx-eabi-gcc 4.9.2
  • arm-xilinx-eabi-as 2.24.51
  • arm-xilinx-eabi-ld 2.24.51
  • arm-xilinx-eabi-objcopy 2.24.51

Guest Operating Systems

LTZVisor supports the following guest operating systems:

• Secure: FreeRTOS, bare metal
• Non-secure: Linux, bare metal

Build & Compile

For build LTZVisor, just run make:

make 

The default configuration targets the ZedBoard platform, uses the Sourcery G++ Lite Toolchain, and setup ups a system with two bare metal VMs.

Optionally it is possible to specify the target board:

• Xilinx Zynq-7000 All Programmable SoC ZC702 Evaluation Kit:

  make BOARD=ZC702

• ZedBoard Zynq-7000 ARM/FPGA SoC Development Board

  make BOARD=ZEDBOARD

• Zybo Zynq-7000 ARM/FPGA SoC Trainer Board

  make BOARD=ZYBO

It is also possible to specify the cross compile toolchain as well as the VMs configuration:

make [BOARD=ZC702] [CROSS_COMPILE=arm-xilinx-eabi-] [S_GUEST=BARE_METAL] [NS_GUEST=BARE_METAL]

(Instructions explaining how to run FreeRTOS as secure guest-OS and Linux as non-secure guest-OS will be added soon).

Demonstration

Before power-on your board, please make sure that you copy the bootloader and LTZVisor binary images to the SD card . The bootloader is provided in the LTZVisor source project under the folder "bootloader". Each board as a specific bootloader. Also, please make sure that your board is configured to boot from the SD card.

1. Power-on your board;

2. Run any terminal and setup the serial port for 115200 bps (baud rate);

3. Stop the autoboot by hitting any key;

4. Type the following sequence of commands:

   • Xilinx Zynq-7000 All Programmable SoC ZC702 Evaluation Kit:

     mmcinfo

     fatload mmc 0 0x3C000000 LTZVisor.bin

     go 0x3C000000

   • ZedBoard Zynq-7000 ARM/FPGA SoC Development Board:

     mmcinfo

     fatload mmc 0 0x1C000000 LTZVisor.bin

     go 0x1C000000

   • Zybo Zynq-7000 ARM/FPGA SoC Trainer Board:

     mmcinfo

     fatload mmc 0 0x1C000000 LTZVisor.bin

     go 0x1C000000

LTZVisor shall start immediately running! For the default system configuration (two bare metal VMs) the secure VM shall blink a set of LEDs every second, while the non-secure VM shall print "Hello World" messages.

References

1. Sandro Pinto, Jorge Pereira, Tiago Gomes, Adriano Tavares, and Jorge Cabral. "LTZVisor: TrustZone is the Key." In LIPIcs-Leibniz International Proceedings in Informatics, vol. 76. Schloss Dagstuhl-Leibniz-Zentrum fuer Informatik, 2017.

2. Sandro Pinto, Daniel Oliveira, Jorge Pereira, Nuno Cardoso, Mongkol Ekpanyapong, Jorge Cabral, and Adriano Tavares. "Towards a lightweight embedded virtualization architecture exploiting ARM TrustZone." In Emerging Technology and Factory Automation (ETFA), IEEE, pp. 1-4., 2014.