T-Kernel Specification (1.B0.02)

1.2. SCALABILITY 3
• Middleware must be designed to meet all the T-Kernel requirements. It cannot be limited to
specific target systems but must be applicable to a variety of systems and scales.
• Providing users with the means for removing or skipping unnecessary functions is allowed.
A “scaled-down implementation” means one that does not provide the entire range of specified functions
but does not behave abnormally (return error, etc.) if a non-implemented function is called. It is
important, in other words, that middleware developed for large-scale systems provide an environment
enabling it to run without problem on other systems. For example, a system that does not use an MMU
can implement the T-Kernel/SM LockSpace() as follows.
#define LockSpace(addr, len)
(E_OK)
The absence of an MMU does not, however, make it allowable not to implement LockSpace() or to
return the error code E NOSPT.
At the same time, when middleware is created, leaving out LockSpace() from an implementation because
the target system does not use an MMU would prevent the middleware from supporting a system that
does use an MMU.
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T-Kernel 1.B0.02