ews00461@uxa.cso.uiuc.edu (11/10/89)
I find the discussion of segmentation very interesting, and I have a few questions which are probably more basic... Suppose I was going to write a compiler for the Mac. My understanding of what this beast should finally create is this: The output would perhaps be a file of type APPL with a number of CODE segments (among a few other things). The CODE segments themselves are of interest to me. Such CODE segments should contain completely relocateable code. All global variables should be reference from A5, (where does A5 get set?). All local variables should be on the stack. All jumps should be relative, if they are in the same segment, and should go through the jump table if they are to another segment (how is this done, I assume there is a toolbox call to do this?) There must be at least 2 (?) segments, 1 jump and 1 with real code. Any insight into this whole area would be very interesting. And obviously, there are a few people on this net for whom this is trivial. Any wisdom to pass on ? Eric W Sink ews00461@uxa.cso.uiuc.edu
d88-jwa@nada.kth.se (Jon Watte) (11/14/89)
In article <227700050@uxa.cso.uiuc.edu> ews00461@uxa.cso.uiuc.edu writes: >I find the discussion of segmentation very interesting, and I have a >few questions which are probably more basic... I too am VERY interested in the inside of the CODE segments. Unfortunately neither the TechNotes nor IM have very much to say (other than you cannot have more than (4096-x, x== ?) jump table entries. (The jump table entries contain code for loading a segment and junmping. In EIGHT BYTES ? What code ? >Suppose I was going to write a compiler for the Mac. My understanding of >what this beast should finally create is this: >(where does A5 get set?). All local variables should be on the stack. >Any insight into this whole area would be very interesting. And >obviously, there are a few people on this net for whom this is >trivial. Any wisdom to pass on ? PLEASE, do ! I've been pulling my hair but decided that "It's probably of no use"... But now that other people as well have asked, my curiosity is KILLING me ! Happy Hacking ! h+ -- This .signature is longer than 4 lines. If you'd like to see it in whole, please send a note to me. I'm h+@nada.kth.se and also h+@proxxi.se 8')
lim@iris.ucdavis.edu (Lloyd Lim) (11/14/89)
The Segment Loader chapter and the Memory Manager diagrams give a fairly
brief but adequate description of how everything works. It does only take
8 bytes to load a segment! (Thanks to a ROM call.)
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Lloyd Lim Internet: lim@iris.ucdavis.edu (128.120.57.20)
Compuserve: 72647,660
US Mail: 146 Lysle Leach Hall, U.C. Davis, Davis, CA 95616t-jlee@microsoft.UUCP (Johnny Lee) (11/15/89)
In article <5930@ucdavis.ucdavis.edu> lim@iris.ucdavis.edu (Lloyd Lim) writes: >The Segment Loader chapter and the Memory Manager diagrams give a fairly >brief but adequate description of how everything works. It does only take >8 bytes to load a segment! (Thanks to a ROM call.) > I think the best reference for Mac programming I've read is Scott Knaster's (spelling?) "How to write Macintosh software". The book has got a very good description about memory management including code segment unloading. Johnny Lee Standard Disclaimer.