 | | RE: signals / legOS internals
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(...) Not to put too fine a point on it, and I hope Kekoa agrees, but the "fluff" is the reason why replacement firmware works in the first place. Without the ROM vectors being dispatched through RAM pointers that are initialized by the ROM and then (...) (25 years ago, 23-Jun-99, to lugnet.robotics.rcx.legos)
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| | Re: signals / legOS internals
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(...) Since it sounds like it might matter to you, I should point out that the interrupt situation on the RCX is a bit more complicated than the H8 manual makes it out to be. Interrupt vectors are in ROM, but the ROM does a dispatch to interrupt (...) (25 years ago, 23-Jun-99, to lugnet.robotics.rcx.legos)
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| | Re: signals / legOS internals
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(...) Yes, that is correct. As for passing parameters to a function, they are simply pushed onto the stack before the function call. Therefore, the H8 stack usually looks something like e.g. this: function param sp+10 function param sp+8 return (...) (25 years ago, 23-Jun-99, to lugnet.robotics.rcx.legos)
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| | Re: signals / legOS internals
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(...) I may have answered my own question here. Since the SP is adjusted before anything is actually done with the local variables, the rule about it always pointing to the last valid datum is not violated even if local variables are placed after (...) (25 years ago, 23-Jun-99, to lugnet.robotics.rcx.legos)
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| | Re: signals / legOS internals
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(...) I may have down and up reversed, since different machines grow the stack upward or downward, and I've worked with a few. I do have push and pop clear in my mind, though. So, yeah, down. So, by the "always" rule, nothing will ever be below the (...) (25 years ago, 23-Jun-99, to lugnet.robotics.rcx.legos)
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