RTEMS CPU Architecture Supplement
The Blackfin architecture supports a simple call and return mechanism.
A subroutine is invoked via the call (call) instruction.
This instruction saves the return address in the RETS register
and transfers the execution to the given address.
It is the called funcions responsability to use the link instruction to
reserve space on the stack for the local variables.
Returning from a subroutine is done by using the RTS (RTS)
instruction which loads the PC with the adress stored in RETS.
It is is important to note that the call instruction does not
automatically save or restore any registers. It is the
responsibility of the high-level language compiler to define the
register preservation and usage convention.
RTEMS CPU Architecture Supplement
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