13.4.7. Downloading a new version of Angel

Angel can download a new version of itself. There are a number of methods you can use to do this, depending on whether you are using armsd or ADW/ADU.

Downloading a new debug agent is often preferable to replacing ROM because it is usually quicker, and does not require you to remove the ROM from its socket and reprogram it with an EPROM programmer. However, downloading a new Angel to RAM is not permanent. If the board is powered down or reset, the downloaded Angel is lost.

The best method is to download Angel to Flash, if your board supports it. This allows you to replace your Angel as often as required, without losing the image at reset or power down. The ARM PID board supports Flash. Refer to your board documentation for more information on downloading to Flash.

If your board does not have Flash, and does have sufficient RAM, you can load Angel to RAM and either run it in place, or relocate and run. If you are using Angel to replace Angel with this method you cannot overwrite the currently executing Angel code.

Note

  • Angel is not always capable of downloading a new copy of itself and then restarting. Your board must contain sufficient spare RAM to copy the new Angel into RAM before relocating it and running it. If you do not have sufficient RAM you can use EmbeddedICE or Multi-ICE to download Angel, providing it has been compiled to run from the download location.

  • Angel is built to relocate a downloaded new Angel to the address that the new Angel is built to execute from, and then to execute it. If you download a copy of Angel that is built to run from ROM, it will fail.

    See Configuring where Angel runs for more information on specifying the Angel execution address.

Using the debuggers to download Angel

From armsd, use the loadagent command to download a new version of Angel. The loadagent command cannot write to Flash. If you use loadagent, Angel must be compiled to run from RAM.

In the ARM debuggers (ADW and ADU), select Flash Download from the File menu to download a new version of Angel to Flash.

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