question about syscall and interrupts......

["machael thailer" <dony.he@huawei.com>]

Hello,
    I find that in handle_sys() of scall_o32.S, it calls:
        SAVE_SOME
    But in the various board interrupt handlers entry(int-handler.S), it
calls:
        SAVE_ALL

    So before entering syscall and interrupt handler entry, why do they need
save different registers? and interrupt need save more things than syscalls?

Thank you very much.

machael thailer