[ECOS] second post SOS pls. Context switching and loading problem.? for sparc target. Thanks

["Qiang Huang" <jameshq at liverpool dot ac dot uk>]

I have asked such simliar question but seems nobody answer me, maybe because
of my poor english, so I check the question I post before and revise them as
much as I can and write it down as the following. And hope this time I can
make it as clear as I can make and maybe any expert can help me a little
bit. Thank you very much.
(I do believe I still have many unclear english explainings in the following
sentence, but may I appologize for that. thank you.)

Q1.
While loading a thread(from very beginning hal_thread_load_context in
context.S ) why need to save the whole register windows set (8 register
windows) before loading the thread's context but the %sp is not saved
anywhere? Isn't the part should be in the hal_thread_switch_context (the
first part before entering into hal_thread_load_context)??


Q2.  When switching from a current thread to a new thread why just one
register window(the last register window) got restored from the stack? How
about the rest register windows (upper register windows)?  if the last
register is 4, how about the register windows 8,7,6,5? no need restore?? but
if return from callee to caller the register window is not the one expected?

Thanks for anything you help.

Best regards!

qiang


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