Jetson Sensor Processing Engine (SPE) Developer Guide

r32.6.1 Release

Compiling and Flashing

This Document describes the steps to build and flash this project


You must download the external Toolchain. NVIDIA does not distribute this toolchain.


Set the appropriate paths for the below variables:

export TOP=<path to root directory where rt-aux-cpu-demo, hwinc and freertos related sources/directories reside>
export CROSS_COMPILE=<path to installed cross compiler>/gcc-arm-none-eabi-4_8-2014q3/bin/arm-none-eabi-
export FREERTOS_DIR=${TOP}/FreeRTOSV8.1.2/FreeRTOS/Source
export FREERTOS_COMMON_DIR=${TOP}/freertos-common
cd rt-aux-cpu-demo

To build for T194 SoC based platforms

make bin_t19x; To build only firmware binary

To build for T186 SoC based platforms

make bin_t18x; To build only firmware binary

To build only doxygen documents

make docs

To build everything

make all

The above commands build all the targets i.e. spe firmware binaries for all the SOCs and Doxygen documents.

Build artifacts

The built SPE firmware binary can be found at /home/dipenp/rel-32-new/rt-aux-cpu-demo/delete_gmc4_32.5/public/l4t-rt/rt-aux-cpu-demo/out/<soc>/spe.bin. The Doxygen build should generate /home/dipenp/rel-32-new/rt-aux-cpu-demo/delete_gmc4_32.5/public/l4t-rt/rt-aux-cpu-demo/out/docs/index.html file. Open it using browser to navigate through documents.

To clean the build artifacts

make clean; To clean firmware and doxygen build artifacts
make clean_t18x; To clean t18x only firmware objects and build artifacts
make clean_t19x; To clean t19x only firmware objects and build artifacts
make clean_docs; To clean only doxygen generated files


  1. Back up the original copies of spe.bin and spe_t194.bin located in the following directory:
  2. Copy the generated ${OUTDIR}/<soc>/spe.bin to the following locating, depending on your target.

    • For the T186 SoC, copy it to:
    • For the T194 SoC, copy it to:

    The Linux_for_Tegra directory is part of the extracted L4T build that you used to flash the Jetson device.

  3. Use the command below to just flash this firmware for Cortex-R5 partition:
    sudo ./ -k spe-fw <T186 or T194 SoC based Jetson platforms> mmcblk0p1