June 2019 - Oberon - mailman3.inf.ethz.ch

Wanted: Oberon Syntax in TextMate, Sublime Text or Atom Grammar
by Treutwein Bernhard 01 Jan '22

01 Jan '22

Does somebody have grammars for Oberon / Oberon-2 / Component Pascal / Active Oberon as grammar for TextMate / Sublime Text / Atom Background: Github wrongly classifies Oberon / Oberon-2 / Component Pascal / Active Oberon as Modula-2. I opened quite some tiome ago an issue in the github/linguist project (https://github.com/github/linguist/issues/3888) and they don't accept EBNF grammars. -- Bernhard Treutwein

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Debugging FPGA oberon via serial line?
by Michael Schierl 29 May '20

29 May '20

Hello, while I was adding UTF-8 support to Fonts and Texts (and almost rewriting Fonts so that a font can be loaded partially and not all glyphs at once), I noticed that debugging such a system can be cumbersome (as you cannot read the TRAP output any more, as well as you have to reset the system to a previous state to be able to fix your mistakes if the screen is too garbled to be useful, or if the system TRAPs during boot). By the way, here is Oberon running in the browser with UTF-8 support for Texts (and Tahoma font): http://schierlm.github.io/OberonEmulator/emu.html?image=UnicodeDiskImage >From other (older) systems, I know it is possible to debug them via serial line, so I was thinking how much the FPGA oberon system needs to be changed (hardware side/software side) to accommodate this. RS232 is supported, so you could use one FPGA system (or emulator) to debug the other one. And I was wondering if anybody already tried doing something like this. I know that Colby Russell worked on debug support in the emulator, but no idea about how far he got. A minimal feature set to be useful (in my opinion) would be - Read and write memory and disk via serial port while the system is running/idle (already possible today via ORC / PCLink) - Set and remove software breakpoints while the system is running/idle - When software breakpoint or trap is hit, save processor state and allow debugging via serial port (-> suspended) - Read and write registers and memory while the system is suspended - Set and remove software breakpoints while the system is suspended - Continue execution when the system is suspended More advanced features would be single stepping (can be emulated by having a look at the instruction and setting software breakpoints at all following locations), or memory breakpoints. Also to be able to enter the debugger by pressing a hardware button on the FPGA (similar to the current reset functionality, but not resetting). And of course symbolic debugging :) Software breakpoints should be easy, just replace instruction by BL to a fixed address. Restore the instruction before returning. For catching TRAPs, overwrite the TRAP address. Saving processor state might be tricky, especially SYSTEM.H and the flags, and maybe you have problems since you need at least one spare register to be able to save the registers to a fixed location in memory. You will also need to switch stack to a second stack before the stack is accessed by the code. Probably solvable by using a special compiler that leaves a register or two unused. Restoring SYSTEM.H and Flags is also not supported (except by searching for instructions that will result in the desired flags or results). Also the question is whether returning to the code will not destroy some flags again. And you need to make sure not to set breakpoints or break at points where a BL has happened but the link register has not been saved yet. So (similar to interrupt) probably some hardware support is needed for this. Entering the debugger by button also needs hardware support (since the current Reset button forgets the PC and some other state). Once in suspend mode, it might be hard to avoid allocating memory, since you cannot run the GC which might collect objects that are still used by the suspended program. But that should be feasible if the functions are basic enough to work with a fixed buffer (e.g. number of breakpoints is limited). I guess memory breakpoints are only possible with hardware support for them (I have no idea how to emulate them except emulating or setting breakpoints at all LOAD/STORE instructions). For symbolic debugging, the compiler would have to write some more debug symbols. For a start, <https://github.com/schierlm/OberonXref/blob/master/ORG.Mod.patch> annotates the code position for every instruction; I currently use it for creating combined source/assembly listings like <https://schierlm.github.io/OberonXref/ProjectOberon2013/ORP.html#both>. But you would probably also need some information about the stack layout (variable names and types) and register contents for every code locatoin, as well as information about module/global variables, and not-exported record types and record members. And you would also need some client to utilize all this information so that you can do something like "Debugger.Inspect F.vwr.dsc" :) So I guess for my own needs, that's too much work for the benefit (especially since I don't know if I will ever try to rewrite any of the core modules again). But perhaps I'm missing something? Any better ideas? Regards, Michael

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Re: [Oberon] A2 Repository (was: Mail.FindObj)
by Treutwein Bernhard 05 Jul '19

05 Jul '19

thanks for the pointer to the metacore repo for A2. Just looking at: https://github.com/metacore/A2OS/commit/2353b6eb64256dfa1373126ba209bb41740… gives us the important hint how to change the Linker.Link statement in Build.Tool for the Bios32 platform, which I guess that it is the new name for native in 32bit. Am 02.06.2019 um 13:48 schrieb Michael Schierl: > [...] > The hardest part was to find the correct Linker.Link line in the dozens > of .Tool, .Text and .Mod files that contain Linker.Link lines. > "Fortunately", some of them used an incorrect syntax (when compared to > Linker.Mod), so all the lines containing \P (instead of --path) or \. > (instead of what?) could be ruled out. -- Bernhard Treutwein (vom Mobiltelefon aus gesendet)

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Shift-Enter to invoke commands in Oberon
by Charles Perkins 18 Jun '19

18 Jun '19

A small change to the Write procedure in TextFrames.Mod allows you to invoke commands from the keyboard using shift-enter. I wrote it up in a tech note: https://github.com/io-core/technotes/blob/master/technote012.md Best Regards, Chuck

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RiscCore VHDL sources
by Walter Gallegos 10 Jun '19

10 Jun '19

For who touch programmable logic hardware and embedded processors, I'm opening a forum about RiscCore, my VHDL version of RISC-5, at www.waltergallegos.com/foro ( Please login for full access ). First posts : RiscCore presentation, source code in VHDL, minimal system example and block diagram. My apologies for those who do not read and write Portuguese or Spanish, the main objective of the forum is the technological exchange in South America main local languages. Regards, saludos Walter

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Re (2): A2 Repository
by peter＠easthope.ca 05 Jun '19

05 Jun '19

From: Paul Reed <paulreed(a)paddedcell.com> Date: Wed, 5 Jun 2019 16:51:43 +0100 > Even if you manage to configure a system to open .Mod files correctly > (maybe even with an automagical Oberon-to-ASCII filter), you've got the > next n systems to configure as well, where n can get boringly large... > :) Thanks Paul. > It's not recent that there are lots of problems opening .Mod files, ... When I checked a few months back, Firefox in Debian Linux opened the Mod files on the ETH server directly. Let's blame the change on Debian rather than ETH. =8~)) Really I don't know what happened and decline to spend more time investigating. The few https://svn-dept.inf.ethz.ch/svn/lecturers/a2/trunk/source/*.Mod I checked this morning are ASCII files. The configuration tweek of Firefox worked for all. The Mod files I put in the wikibook are HTML created via Oberon.MediaWiki.Mod as illustrated in https://en.wikibooks.org/wiki/Oberon#Dataflow_of_a_Text . The upload process might be more automated in the future. From the viewpoint of the reader, just click to see, as expected. Easy-peasy and almost 100% reliable. HTML is the most universal language at present. It has attributes. It has non-text content. Any browser should open it. Anything else has a problem. Oberon Text is a show-stopper for many novices. TXT lacks attributes. Etc. Thanks again, ... Lyall E. -- Composed and transmitted by software designed to avoid the complication and vulnerability of antivirus software. Tel: +1 604 670 0140 Bcc: peter at easthope. ca

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A2 Repository
by peter＠easthope.ca 05 Jun '19

05 Jun '19

> https://svn-dept.inf.ethz.ch/svn/lecturers/a2/trunk/source/ Currently, Firefox presumes a Mod file is an Amiga SoundTracker audio file and fails to open it. Appears the behaviour derives from the file name extension although not with files from the preceeding server. A recent Firefox upgrade? The snag is easily resolved by opening Preferences > General > Applications. Then for "Amiga SoundTracker audio" change the action to an editor. Leafpad works for ASCII files. Gedit is bigger and slower but will open an Oberon Text; probably not necessary. Regards, ... Lyall E. -- Composed and transmitted by software designed to avoid the complication and vulnerability of antivirus software. Tel: +1 604 670 0140 Bcc: peter at easthope. ca

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Re: [Oberon] Do commands
by peter＠easthope.ca 04 Jun '19

04 Jun '19

From: Charles Perkins <chuck(a)kuracali.com> Date: Mon, 3 Jun 2019 18:57:04 -0700 > I think I recall some earlier Oberon systems having a way to 'do' a > bunch of commands just as though you had clicked them in sequence... > but a brief Internet search didn't turn up anything. Anybody have a > reference ... Configuration.DoText, Configuration.DoCommands and ET.Do. To see the sources, open Oberon.Configuration.Mod and Oberon.ET.Mod in the left column of the table. https://en.wikibooks.org/wiki/Oberon/A2#Sources,_Tools_and_Configuration_Te… Regards, ... Lyall E. -- Composed and transmitted by software designed to avoid the complication and vulnerability of antivirus software. Tel: +1 604 670 0140 Bcc: peter at easthope. ca

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TeroBuild: a new way to build Oberon disk images
by oberon＠x.colbyrussell.com 04 Jun '19

04 Jun '19

I've re-implemented parts of Peter De Wachter's Project Norebo to eliminate the dependencies on C and Python. In the past, I've discussed with Michael Schierl the importance we both placed on his in-browser emulator's ability to run even on computers with old versions of Internet Explorer installed and no admin access to install or run other software (such as newer/other browsers, or a copy of Peter's SDL-based emulator). I've done some work so anyone can now use an offshoot of Project Norebo to build system images from the most recent Oberon source code modules even if you have neither a C compiler handy nor Python installed locally. Here's a two minute video demonstrating this: https://www.youtube.com/watch?v=TUpd70Mu0Ek In the video, I actually do two builds: once by opening Build.app.htm in the browser, and another by using it directly from the terminal. (This is part of work I've been doing for triplescripts.org, where I implore people to revisit the assumptions they make about their software projects and ask what it should take for another person to dive and begin working on the code. The idea is that too many times software developers wind up with tunnel vision and assume others have the time to burn to get a "development environment" set up, even though this often isn't necessary. In many cases the build scripts can be made to run using nothing more than what most most people have already installed on their computers--i.e., a browser, which is the closest thing the world has to a universal application runtime. I see this as also being important regarding matters of reproducibility and the long-term preservation of computing history.) Unfortunately, I didn't take the time to make this Build.app.htm work in Internet Explorer. You'll need a reasonably modern browser to make use of it. A hacked copy of the Norebo source tree with my TeroBuild changes applied can be found on Keybase by cloning repo at: keybase://public/crussell/norebo.git And in case you don't have Git or Keybase installed (see what I mean about developer tunnel vision?), an archive can be downloaded from: https://keybase.pub/crussell/TeroBuild.zip -- Colby Russell

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Mail.FindObj
by peter＠easthope.ca 02 Jun '19

02 Jun '19

MODULE Mail IN Oberon; ... PROCEDURE Show*; ... obj := FindObj("MailList"); ... END Show; The module is visible at https://en.wikibooks.org/wiki/Oberon/A2/Oberon.Mail.Mod . If message n exists, Show n ~ shows it; so obj # NIL. Yet this procedure always reports "obj is NIL." (** Display salient information of message number no. In absence of no, survey all messages. Survey [no] ~ *) PROCEDURE Survey*; VAR S: Attributes.Scanner; obj: Objects.Object; m, n: LONGINT; BEGIN Attributes.OpenScanner(S, Oberon.Par.text, Oberon.Par.pos); Attributes.Scan(S); IF S.class = Attributes.Int THEN (* message number specified. *) IF (0 <= S.i) & (S.i < noMsgs) THEN obj := FindObj("MailList"); IF obj # NIL THEN Texts.WriteString(W, "obj is not NIL."); Texts.WriteLn(W); m := S.i; n := m+1 ELSE Texts.WriteString(W, "obj is NIL."); Texts.WriteLn(W) END END ELSE (* Survey all messages. *) m := 0; n := noMsgs END; IF m < n THEN Texts.WriteString(W, "Msg no. From To Subject"); Texts.WriteLn(W) END; WHILE m < n DO Texts.WriteInt(W, m, 4); Texts.Write(W, " "); Texts.WriteLn(W); INC(m) END; Texts.Append(Oberon.Log, W.buf) END Survey; How can obj always be NIL in Survey but not in Show? Incidentally, https://trac.inf.ethz.ch/trac/lecturers/a2/browser/trunk/source/Oberon.Mail… was functional a few months back. Now gives, "Error TracError: IOError: [Errno 2] No such file or directory: '/import/lecturers/svn/repositories/a2/trac/VERSION'" Any clues about trac? Thanks, ... Lyall E. -- Composed and transmitted by software designed to avoid the complication and vulnerability of antivirus software.

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