Software Development Tool Chain

ARM supplies a CD with an evaluation version of its software tool chain with each Evaluator-7T board. This software may be used for development, but will need to be purchased after the evaluation period is complete.

However, we use (and recommend) a completely free software tool chain, including an embedded, real time, operating system.

eCos: Embedded Operating System

eCos - the embedded Configurable operating system, originally developed by Red Hat, is an open source, royalty-free operating system designed for deeply embedded applications. eCos, as its name suggests, is extremely configurable with the following being availble to include in a configuration if required.

• Hardware Abstraction Layer (HAL)
• Real-time kernel with:
• Interrupt handling
• Exception handling
• Choice of schedulers
• Thread support
• Rich set of synchronization primitives
• Timers, counters and alarms
• Choice of memory allocators
• Debug and instrumentation support
• ISO C and math libraries
• Serial Device Drivers
• Ethernet Device Drivers
• Zlib Comression/Decompression support
• USB Peripheral Support
• RAM filesystem
• ROM filesystem
• JFFS2 FLASH filesystem
• Posix API
• µITRON API
• Full TCP/IP (BSD) stack
• Light weight TCP/IP (lwIP) stack
• Embedded HTTP server
• Embedded VNC server (Remote control and display system)
• Microwindows GUI

Because of its open source nature, this list is constantly being extended. All this means that eCos can be varied from an extremely simple OS with a minimal resource footprint (about 50KBytes), to an extreamly rich featured OS for complex embedded applications.

For full details see the eCos homepage.

Sweeney Design supplies all the additional code required to convert the eCos port for the basic Evaluator-7T board to work with the Evaluator-7T board and E7T-DBoard combination. This enables the use of the additional SDRAM and sets up the µController to correctly interface with the FPGA.

RedBoot: Bootstrap Firmware

RedBoot - the Red Hat Embedded Debug and Bootstrap firmware is a complete bootstrap environment for embedded systems (actually an eCos application using just the HAL). RedBoot contains GDB stubs, in order to work with GDB (the GNU debugger) and through this makes possible the download, execution and debug of embedded applications, including eCos applications via serial or ethernet.

A command-line interface is also provided (via serial or ethernet) to allow the usual bootstrap functions of downloading images, executing code, examining memory contents, writing to memory and more. This is fully configurable, allowing unnecessary functions to be removed to optimise RedBoot's memory footprint.

For full details see the RedBoot homepage.

Sweeney Design supplies additional code, to extend RedBoot, enabling it to configure the Xilinx FPGA on the E7T-DBoard. On power-up, RedBoot will configure the FPGA using an (optionally compressed with gzip) image stored in the FLASH on the Evaluator-7T. Alternatively an FPGA image may be downloaded to RAM (via X-modem or Y-modem over serial, or TFTP over ethernet) using RedBoot's load command and then used to configure the FPGA using the additional fpgaload command.

Insight/GDB: Software Debugger

GDB - the GNU Debugger is a powerfull software dubugger that allows you see 'inside' an embedded application while it executes. GDB allows you to:

• Download a program to your target over serial or ethernet.
• Start the program, specifying anything that might affect its operation.
• Make the program stop on specified conditions.
• Examine what has happened when the program has stopped.
• Change things in the program, to correct the effects of bugs and check for more bugs.

For full details see the GDB section of Red Hat's website.

Insight is simply a graphical front end for the GDB written in Tcl/Tk. Although GDB can be used without Insight (and many prefer to use it this way), Insight makes using GDB far more intuitive for those who are used to using GUIs.

For full details see the Insight section of Red Hat's website.