BSP Developer's Guide

VxWorks 5.5
BSP Developer’s Guide
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Using a logic analyzer to trace the processor’s address lines.
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Writing a debugging library to do something like the following:
– Flash an LED.
– Write to persistent memory (local, off-board, or battery backed memory).
– Transmit a character over a serial line in polled mode.
– Send data up through the NetROM debug port.
After you have chosen a debugging mechanism, check that you can jump to your
code’s entry point and run it successfully. Your test code should set up the board’s
RAM as needed and prove that it is working by writing to it and reading back the
value. Your test program will probably use the same initialization code as
VxWorks. For details on the files romInit.s and sysALib.s, see 3.3.1 Writing the BSP
Files, p.44.
NOTE: If you are testing a debugging library on a ROM-based VxWorks image, be
aware that the data and bss segments are not yet set up. In particular, libraries that
depend on the correct initialization of global variables cannot work yet.
3.3 Writing the BSP Pre-Kernel Initialization Code
This section describes how to write the BSP files, build and download VxWorks,
debug the initialization code, and how and when to start the WDB agent before
you start the kernel.
3.3.1 Writing the BSP Files
Create a BSP directory by copying the BSP template files from
target/config/templateCPU. Below is a file-by-file description of considerations to
keep in mind when modifying the files.
44