RTEMS CPU Architecture Supplement
The MC68xxx architecture supports a simple yet
effective call and return mechanism. A subroutine is invoked
via the branch to subroutine (XXX) or the jump to subroutine
(XXX) instructions. These instructions push the return address
on the current stack. The return from subroutine (XXX)
instruction pops the return address off the current stack and
transfers control to that instruction. It is is important to
note that the XXX call and return mechanism 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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