December 2017 - Oberon - mailman3.inf.ethz.ch

FPGA - Screen.Mod
by Tomas Kral 26 Oct '18

26 Oct '18

Hi, EDIT (1) I am looking for `Screen.Mod' module (mainly its `Screen.Grub' command) hinted in PO2013 pictures. I have completed early version of `Bitmaps.Mod' supporting basic set of raster operations. I wish to share pictures and code. As we may not post attachments to the forum, I could expose to GitHub, there is also `WikiBook' run by Lyall E. Please advise. Many thanks. -- Tomas Kral <thomas.kral(a)email.cz>

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FPGA Oberon - Definition Module Tool
by thomas.kral＠email.cz 08 Oct '18

08 Oct '18

Hi, I am thinking of a simple tool that could extract definition info from *.Mod and produce respective *.Def file. Definition files can be quickly looked at, to remind a programmer of the interface *.Mod modules export. While on Linux one could use grep $ grep PROCEDURE\ * *.Mod.txt to obtain info at least about procedures, but how about exported types and variables? I am looking for a recommended way how to simply code such a tool, is it a good idea to use `ORP' parser somehow for the task? I prefer to code it simple, does not have to be perfect, but should carry the idea. Tomas

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WIP: Project Oberon / ARM Linux
by Peter Matthias 23 Mar '18

23 Mar '18

Hi all, an untested public version of PO/L is available at http://oberon.wikidot.com Regards, Peter

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Project Oberon inner core and disk image creation
by Andreas Pirklbauer 16 Jan '18

16 Jan '18

> On Thu Oct 12 19:09:15 CEST 2017 Peter Matthias wrote: > > Hello, > are static linker and tools to create the disk image > available for Project Oberon? > > Peter > A minimal version of the system "building tools" for Oberon 2013 is at: github.com/andreaspirklbauer/Oberon-building-tools It allows one to create a new inner core and load the generated image onto the boot area of the local disk.

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Branch instruction, program counter and link register
by Srinivas Nayak 03 Jan '18

03 Jan '18

Dear All, In RISC-5, why not every branch instruction saves PC+4 to R15? Any disadvantages? With thanks and best regards, Yours sincerely, Srinivas Nayak Home: http://www.mathmeth.com/sn/ Blog: http://srinivas-nayak.blogspot.in/

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FJump and FixLink
by Srinivas Nayak 22 Dec '17

22 Dec '17

Dear All, ORG.Mod: In FJump(), we have Put3(BC, 7, L); it means, L is offset which occupies 24 bits. But in FixLink() we see L1 := code[L] MOD 40000H; Why we extract only 18 bits to L1? With thanks and best regards, Yours sincerely, Srinivas Nayak Home: http://www.mathmeth.com/sn/ Blog: http://srinivas-nayak.blogspot.in/

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Exporting pointers
by Andreas Pirklbauer 21 Dec '17

21 Dec '17

> We have used “exno" for Procedures and Vars as well. The key idea here is to keep symbol files stable even if the implementation, but not the interface, of a module changes. This is achieved by including a running number (exno) rather than absolute addresses (of procedures and variables) in symbol files. In the case of record types, exno actually refers to its type descriptor. The object file also uses these export numbers, e.g. in instructions. The translation to actual memory addresses is deferred to module load time (when the destination address of a module is known). This is why there is code to “fix up” the chain of export numbers at the end of the loader (procedure Modules.Load). But all this is explained in great detail in the book Project Oberon 2013 Edition, e.g. chapter “12.6.1. The structure of the symbol table”. Careful reading of the book, together with tracing the code should answer most of your questions. The book really is quite complete. There is hardly any concept or implementation aspect that is not presented. Also, you can use the tools ORTool.DecSym and ORTool.DecObj on some test programs to further deepen the understanding of the various concepts.

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Exporting pointers
by Srinivas Nayak 21 Dec '17

21 Dec '17

Dear All, Looks like the current RISC-5 Oberon7 compiler allows only RECORDs to be exported, although language says a pointer type can also be exported. I see export number only incremented in case of RECORD type in ORP.Mod. Kindly let me know if I am mistaken. With thanks and best regards, Yours sincerely, Srinivas Nayak Home: http://www.mathmeth.com/sn/ Blog: http://srinivas-nayak.blogspot.in/

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(no subject)
by Srinivas Nayak 20 Dec '17

20 Dec '17

Dear All, Looks like the current RISC-5 Oberon7 compiler allows only RECORDs to be exported, although language says a pointer type can also be exported. I see export number only incremented in case of RECORD type in ORP.Mod. Kindly let me know if I am mistaken. With thanks and best regards, Yours sincerely, Srinivas Nayak Home: http://www.mathmeth.com/sn/ Blog: http://srinivas-nayak.blogspot.in/

2 1

What does procedure BuildTD do?
by Srinivas Nayak 18 Dec '17

18 Dec '17

Dear All, What does procedure BuildTD of ORG.Mod do? https://www.inf.ethz.ch/personal/wirth/ProjectOberon/Sources/ORG.Mod.txt What is the purpose and idea behind it? Is s := (s+263) DIV 256 * 256 correct? or should it be s := (s+255) DIV 256 * 256 ? With thanks and best regards, Yours sincerely, Srinivas Nayak Home: http://www.mathmeth.com/sn/ Blog: http://srinivas-nayak.blogspot.in/

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