GRBOOT

Overview

GRBOOT is an implementation of the ESA requirements document SAVOIR Flight Computer Initialisation Sequence (SAVOIR-GS-002). The software is developed in accordance with European Space Agency software engineering standards ECSS-E-ST-40C and ECSS-Q-ST-80C, tailored software criticality category B.

GRBOOT is divided into four main parts; initialization, self-tests, standby extension point and application loader. The application loader selects one out of two application images to load, verify and start with optional one of the images as fall back. An interface is provided for users to integrate a custom standby application for low-level maintenance operations before the application loader is executed.

Use cases

Boot loader. This is the baseline use case and provides reliable application loading meeting common requirements for booting payload and on-board flight computers.
Boot loader with maintenance (standby) mode. An extension point is available which allows for implementation of a custom software controlled maintenance mode which executes from ROM. It can for example be used to manage on-board memories over a network, such as PUS over SpaceWire using the available standby implementation described above.
ROM resident application. In this use case, the application is linked directly into the GRBOOT image and no application is loaded from external memory. It is useful for smaller control-type applications where a robust run-time is required.

Architecture

Key Tech Spec

Target technology support

Evaluation boards

Ordering information

Development Kit

Licensing

Software

Tools

Block diagram

Supported Hardware

Configuration

Reference Design

Other resources

Detailed features

Implements the ESA "SAVOIR Flight Computer Initialisation Sequence" (SAVOIR-GS-002).
Developed in accordance with ESA software engineering standards ECSS-E-ST-40C and ECSS-Q-ST-80C, tailored software criticality category B.
Multi-processor support (SMP, AMP)
Initialization: CPU, FPU, caches, peripherals, etc.
System self-tests: CPU, L1/L2 caches, ROM, external memories, etc.
Self-test results are recorded in a Boot report, available to the loaded application.
Separation of Boot Memory and Application Storage Memory: Updating application does not require updating the boot loader.
Application images can be stored in local non-volatile memory, including parallel memories and SPI flash.
ELF-like application image format with support for in-flight patching.
Optional application compression.
Application images are integrity checked before execution, with failover on failure.
User extension points for custom initialization and user defined Standby Mode.
Prepares environment compatible with multiple operating system (RTEMS, VxWorks, Linux, BCC, PikeOS, SMP, AMP, etc.)
SpaceWire/PUS Standby software (optional, GRBOOT-STANDBY license)