BSP Developer's Guide

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BSP Organization
can have very undesirable effects for customers using multiple BSPs from different
sources. Only Wind River original code is allowed in these directories.
Confusing Configuration Options
In the file config.h, the user should be presented with clear choices for configuring
the BSP. Material where the user does not have a choice should not be in config.h,
it should be in bspname.h. The user should not have to compute values to be
entered into config.h. If a register needs to be loaded with the high 16 bits of an
address, the user should enter the full address. The code does the computation of
the value to load in the register. The user should not have to do this; see BSP
Contents, p.196.
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Using Non-Maskable Interrupts (NMI)
Because the wind kernel uses intLock( ) as the primary method for protecting
kernel data structures, using non-maskable interrupts (NMI) should be avoided. If
an NMI interrupt service routine (ISR) makes a call to VxWorks that results in a
kernel object being changed, then protection is lost and undesirable behavior can
be expected. For more information on ISRs at high interrupt levels, refer to the
VxWorks Programmer’s Guide: Basic OS.
Also note that a VxWorks routine marked as interrupt safe does not mean it is NMI
interrupt safe. On the contrary, many routines marked as interrupt safe are actually
unsafe for NMI.
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