User`s guide

VxWorks

BSP Developer’s Guide, 6.0

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Use 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 the tool. The

advantages include fast download times, portability to most boards, and a

communication protocol that lets debugging messages pass from the target to

the host through the ROM socket. For more information on ROM emulators,

see ROM Emulator, p.45).

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Use an OCD device (see On-Chip Debugging (OCD) Devices, p.45). This allows

you to single-step through much of the initialization code.

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Use an ICE (see In-Circuit Emulator, p.46). The main drawbacks of this

approach include a high procurement cost and a lack of availability for all

processors. However, it does let you single-step through the initialization code

and can significantly improve a product’s time to market.

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Use the WDB agent (see 2.4.2 WDB Debugging Interface, p.47). Once the WDB

agent is available, many parts of BSP initialization can be downloaded and

tested while running. In addition to a fast, efficient download path, this gives

you access to the Wind River tools, including the full capabilities of the

debugger.

After you have downloaded code to the target, examine memory or ROM to make

sure your code is loaded in the right place. The GNU tools nmarch and

objdumparch, supplied by Wind River, can be used on your compiled images to

see what should be in the target memory. When reviewing this information, give

special attention to the start addresses of the text and data segments.

2.5 Avoiding Common Problems

Most of the problems listed in this section are the result of doing the right thing in

the wrong place or at the wrong time. Context is important. To avoid introducing

problems into your BSP, examine your reference BSP carefully before starting your

development and ensure that the reference BSP developer did not make the

following mistakes.

Failing to Include LOCAL_MEM_LOCAL_ADRS

Many BSP writers assume that LOCAL_MEM_LOCAL_ADRS is zero and fail to

include it in macros that must be offset by the start of memory.