T-Kernel Specification (1.B0.02)

210 CHAPTER 4. T-KERNEL/OS FUNCTIONS
[Additional Notes]
Extended SVC handlers as well as break functions, startup functions, cleanup functions and event
handling functions all have the equivalent of the TA HLNG attribute only. There is no means of designating
the TA ASM attribute.
Prior to initialization of a resource control block by a startup function, and after resource release by a
cleanup function, the behavior if an extended SVC is called by a task belonging to that resource group
is dependent on the subsystem implementation. The OS does not make any attempt to prevent this
kind of call. Basically it is necessary to avoid calling an extended SVC before calling a startup function
and after calling a cleanup function.
There may be cases where, for some reason or other, a break function, cleanup function or event handling
function is called without first calling a startup function. These functions must execute normally even in
such a case. A resource control block is cleared to 0 when it is first created and when cleanup processing
is executed by tk cln ssy. Accordingly, even if it was not initialized properly by a startup function,
the resource control block can still be assumed to have been cleared to 0.
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T-Kernel 1.B0.02