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[REBOL] Re: you'll think I'm crazy, but...

From: chaz:innocent at: 29-Oct-2000 13:45

Not a crazy thing at all. A person (Marcus Petersson <[d4marcus--dtek--chalmers--se]>) on another mailing list that I subscribed to (KOSH - Kommunity Operation System and Hardware) has created an implementation of the KOSH Simple Virtual Machine (SVM) in REBOL. Its "assembly language" is a REBOL dialect. This is from his readme ~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~ Installation ------------ Put the files wherever you want. Start Rebol. Type "do %svm.r" including relative path to load svm.r. Usage ----- There are (ATM) four user functions. Although nothing stops you from accessing other functions or variables, you shouldn't need to. Since everything is packed within one large object, you will have to precede every command by "svm/". - svm/regs: Prints a nice table showing the contents of all registers. - svm/clear-regs: Reset all registers to zero. - svm/parse-i: The main function. Trims the code and parses it. It is used by parse-file, but you can use it directly. The input should be a string containing at least one correct instruction. If parse-i finds a bad instruction, it stops and reports the name. Not very helpful I guess, but it will do for now. Otherwise it runs until the end and says ok. The syntax of the instructions (Rebol is case-insensitive by default): name operands (opt data) Operands are on the form $0 up to $f. Data is on the form #0123cdef for hex, or 19123695 for integer. For example: inc $0 ori $4, #00000066 xori $5, 100 notand $9, $6 addi $1, $0, 20 shifti $e, $e, #00000002 mod $4, $b, $0 - svm/parse-file: Wants a filename as argument. This file is read and passed as a string to parse-i. Example: "svm/parse-file %svm1" svm/clone-file: Wants two filenames (infile outfile) and an integer (times) as argument. The infile is read and copied times times to a buffer, which is then written to the outfile. A large file of code can be useful to test the speed. Todo ---- There are 7 instructions that aren't handled: tls and tlsi: Because implementing binary data types in Rebol is complicated. tls, loadi, load, storei, store: Needs some form of simulated memory. It would be cool to read instructions (in binary form) from the memory as well. This also require a pc and an instruction fetcher and decoder. branch: Also require memory and pc. The memory concept is interesting. The parse function would, instead of running the instructions directly for asm, translate them from asm to binary format. Another function, possibly the memory handler, would load the code into the memory. Then a decode function would fetch and decode the binaries from the adress which is pc's value. One function could run the code continously, yet another could step through it. Supposedly you could read and write binary code to disk too. After all the above works, perhaps we could simulate cacheing, virtual memory, interrupts and timers. Then we could build a bus, and hook some simulated hardware to it. Maybe we could let a Rebol/View window change colors according to the data in the "graphics card". :-) Bugs ---- Plenty. If you follow the usage guide, I hope you won't trip over too many. ~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~ Here's his response to my suggestion that he post it here. ~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~ on Sat, 28 Oct 2000, chaz wrote:
> This is great! Makes one wonder what would happen if you added a little > introduction to the aims of kosh, and crossposted this to
[rebol-list--rebol--com] Uhmm no. This certainly isn't anything that would interest people in general. Not to metion I would get bashed, first for crossposting, then for writing lousy Rebol code. :-( ~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~ If you're interested, you can contact him directly or subscribe to the KOSH list. To subscribe to the mailing list, send a mail to [MDaemon--chaossolutions--org] with: subscribe kosh as the only line in the body. You will then receive an authorisation mail - reply without changing it. You're subscribed when you receive the list welcome mail. chaz At 12:33 PM 10/29/00 +0000, you wrote:
>I was wondering if it would be possible to create a sparc assemby dialect
for rebol. It would be useful for prototyping assembly code for my assembly class (without need a sparc machine or assembler).