My real-time operating system
ericw.ca
My real-time operating system
1–10 of 27 posts
Re: My real-time operating system
#2I wrote a toy operating system for school that I recently(ish) released to the world. It comes with source code and design documents so I thought it might be interesting for people to poke around in.
Re: My real-time operating system
#3I wrote a toy operating system for school that I recently(ish) released to the world. It comes with source code and design documents so I thought it might be interesting for people to poke around in.
Looks like fun! What kind of drivers does it have? And what license?
Re: My real-time operating system
#4I wrote a toy operating system for school that I recently(ish) released to the world. It comes with source code and design documents so I thought it might be interesting for people to poke around in.
Looks like fun! What kind of drivers does it have? And what license?
It was fun! Well, fun modulo writing and debugging all the code in three months.
As for drivers, the OS really only interfaces with 8250 UARTs; both the VT100 terminal and the Marklin digital interface for the trains were connected via RS-232 serial ports. There is also, embedded in the kernel, a micro VGA driver for displaying debug messages.
I don't exactly have a specific open source license in mind. Right now I suppose you could say it's public domain. I'd be happy for it to stay that way, unless somebody would like to convince me otherwise?
Re: My real-time operating system
#5Earlier quoted context omitted.
Looks like fun! What kind of drivers does it have? And what license?
It was fun! Well, fun modulo writing and debugging all the code in three months. As for drivers, the OS really only interfaces with 8250 UARTs; both the VT100 terminal and the Marklin digital interface for the trains were connected via RS-232 serial ports. There is also, embedded in the kernel, a micro VGA driver for displaying debug messages. I don't exactly have a specific open source license in mind. Right now I s…
If you want it to be public domain, you could use the Creative Commons Public Domain Deed to clarify that. Right now, if I were to download your code, decide not to use it, write something similar, make a successful commercial open-source product from it, and then you got hit by a bus and your sister inherited your copyright, she could sue me on the theory that you didn't really know what it meant when you said, "I suppose you could say it's public domain."
It's a little depressing to hear you say it took you three months working really hard, because it means it would probably take me about the same time. (I have no reason to think I'm any smarter than you are.) Maybe I should stick to AVRs for real-time stuff...
Re: My real-time operating system
#6Ah, that video brings back nice memories of bleary-eyed nights in the Real-Time lab. :)
... That and rage at the crappy, broken, unreliable sensors we had at the time. Damn hardware always messing with pretty software abstractions.
What was your gratuitous fluff process to "prove" that the OS was mostly real-time-ish?
Re: My real-time operating system
#7Earlier quoted context omitted.
It was fun! Well, fun modulo writing and debugging all the code in three months. As for drivers, the OS really only interfaces with 8250 UARTs; both the VT100 terminal and the Marklin digital interface for the trains were connected via RS-232 serial ports. There is also, embedded in the kernel, a micro VGA driver for displaying debug messages. I don't exactly have a specific open source license in mind. Right now I s…
If you want it to be public domain, you could use the Creative Commons Public Domain Deed to clarify that. Right now, if I were to download your code, decide not to use it, write something similar, make a successful commercial open-source product from it, and then you got hit by a bus and your sister inherited your copyright, she could sue me on the theory that you didn't really know what it meant when you said, "I s…
Aha, well I'm an only child! Either way, I added some text saying everything is licensed under a Creative Commons Attribution 2.5 Canada License; thanks for the advice.
I'll plead ignorance with your second sentence. AVRs? And why should it depress you that it took me three months? (Keeping in mind that I was taking other classes at the time, and that there was a ton of competition for lab space.)
Re: My real-time operating system
#8Ah, that video brings back nice memories of bleary-eyed nights in the Real-Time lab. :) ... That and rage at the crappy, broken, unreliable sensors we had at the time. Damn hardware always messing with pretty software abstractions. What was your gratuitous fluff process to "prove" that the OS was mostly real-time-ish?
Demonstrating that the OS was real-ish time consisted of showing that (1) it never dynamically allocates memory, (2) it uses constant-time algorithms. More practically I did a bunch of timing to show that, under real loads, it generated responses under certain (arbitrary) thresholds. In conclusion: a process lacking even the smoke and mirrors of rigor.
Re: My real-time operating system
#9Earlier quoted context omitted.
If you want it to be public domain, you could use the Creative Commons Public Domain Deed to clarify that. Right now, if I were to download your code, decide not to use it, write something similar, make a successful commercial open-source product from it, and then you got hit by a bus and your sister inherited your copyright, she could sue me on the theory that you didn't really know what it meant when you said, "I s…
Aha, well I'm an only child! Either way, I added some text saying everything is licensed under a Creative Commons Attribution 2.5 Canada License; thanks for the advice. I'll plead ignorance with your second sentence. AVRs? And why should it depress you that it took me three months? (Keeping in mind that I was taking other classes at the time, and that there was a ton of competition for lab space.)
Creative Commons Attribution is not the Public Domain, and it's not a good idea to use the CC licenses for source code.
If what you want is for the code to always have your name on it, you should use a 4-clause BSD license (the original one with the advertising clause).
Re: My real-time operating system
#10Ah, that video brings back nice memories of bleary-eyed nights in the Real-Time lab. :) ... That and rage at the crappy, broken, unreliable sensors we had at the time. Damn hardware always messing with pretty software abstractions. What was your gratuitous fluff process to "prove" that the OS was mostly real-time-ish?
Demonstrating that the OS was real-ish time consisted of showing that (1) it never dynamically allocates memory, (2) it uses constant-time algorithms. More practically I did a bunch of timing to show that, under real loads, it generated responses under certain (arbitrary) thresholds. In conclusion: a process lacking even the smoke and mirrors of rigor.
Sorry, I didn't mean to imply your measuring process was fluff.
When I did 452 we had to do something on-screen, to demonstrate responsiveness. I did the "water demo effect" (similar to http://www.derschmale.com/demo/pixelbender-water/PixelBender...). It had to animate without hitching under load, which I guess correlates with your response timing tests (the arbitrary threshold being 60 or 30 Hz in this case).
Anyhoo, I meant "process" in terms of OS-level process, and "fluff", because mine was just lame graphical fluff. :)
btw, planning any more co-op terms before you graduate? Drop me a line.