BSP Developer's Guide

3
Creating a New BSP
3.2 Setting Up Your Development Environment
Setting up your development environment means establishing a mechanism to
download code to the target and then testing the downloaded code. It is usually
best to start with some simple image test code rather than a full blown VxWorks
image. To find out what compiler and linker flags you need, go to your reference
BSP and build either vxWorks (a RAM image) or vxWorks_resrom_nosym (a
ROM image).
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Choosing a Technique for Downloading Code to the Target
The following are some of the more common techniques for downloading code to
the target:
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Using the download protocol supplied in the board vendor’s debug ROMs.
The drawback of this approach is that downloading is often slow. The
advantage is that it is easy to set up.
Using a JTAG debugger such as a visionICE or visionPROBE emulator. The
main drawback of this approach is that support is not available for all
architectures and/or CPUs. However, this method allows for a quick
download and also allows you to single-step through the initialization code.
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Using a ROM emulator (such as NetROM from AMC). The drawback of this
approach is that it can take time for you to learn how to use it. The advantages
include fast download times, portability to most boards, and a communication
protocol that lets debug messages pass from the target to the host through the
ROM socket.
After you have downloaded code to the target, examine memory and/or ROM to
make sure it is loaded into the right place. The Wind River-supplied GNU tools nm
and objdump can be used on your compiled images to see what should be in the
target memory. Pay special attention to the addresses of the start of the text and
data segments.
Choosing a Method for Testing the Downloaded Code
The next step is to establish a debugging mechanism to track the progress of your
initialization sequence. The following are some of the more common techniques:
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Using a JTAG device such as visionICE or visionPROBE.
Using the board’s native debug ROMs (if it has breakpoint support).
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