Post by thread:[PIC:] Want to port Linux to PIC16f877...Help need

hi, hi to all you big guys there..man ..after reading your questions and answers i feel i m still in nursery :( anyway heres my question: I want to develop (or rather 'Port') the linux kernel on to the Pic16f877. Now the reason I wish to do this is: 1. I have to present a research paper due on april 22nd on the topic Real Time operating Systems: Case Study Microcontrollers. 2. I think since both Linux and PIc are so very commercially successful in there respective domains that it would be good idea to combine them in some way. 3. I love linux and the PIC and couldnt think of a better topic. About the Real time part I think i will save that till later that is after I have finsihing porting Linux to the PIC (if I am able to do it i.e.) Now i went through a book - Building Embedded Linux Systems ..and it says that it isnt easy (not impossible ) though to port linux on to a 'less than 32 bit' microcontroller or microprocessor. So I am stuck now! since Microchip doesnt offers a 32 bit microcontroller. Please suggest me something! anything! Thankyou Bye Vishal --------------------------------- Do you Yahoo!? Yahoo! Small Business $15K Web Design Giveaway - Enter today -- http://www.piclist.com hint: To leave the PICList spam_OUTpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu

What the book says is very valid. Even if you could reduce the Linux kernel to something that would run on a 16F877 it wouldn't really resemble a Linux kernel anymore. The 16F877 is a comparitively low end microcontroller and lacks a vast majority of the hardware features to run something as advanced as Linux. This isn't an April fools joke by any chance? WM On Wed, Mar 31, 2004 at 08:26:16PM -0800, Vishal Changrani wrote: {Quote hidden}> hi, > hi to all you big guys there..man ..after reading your questions and answers i feel i m still in nursery :( > anyway heres my question: > I want to develop (or rather 'Port') the linux kernel on to the Pic16f877. Now the reason I wish to do this is: > 1. I have to present a research paper due on april 22nd on the topic Real Time operating Systems: Case Study Microcontrollers. > 2. I think since both Linux and PIc are so very commercially successful in there respective domains that it would be good idea to combine them in some way. > 3. I love linux and the PIC and couldnt think of a better topic. > About the Real time part I think i will save that till later that is after I have finsihing porting Linux to the PIC (if I am able to do it i.e.) > > Now i went through a book - Building Embedded Linux Systems ..and it says that it isnt easy (not impossible ) though to port linux on to a 'less than 32 bit' microcontroller or microprocessor. So I am stuck now! since Microchip doesnt offers a 32 bit microcontroller. > Please suggest me something! anything! > > Thankyou > Bye > Vishal -- Wesley Moore - .....wmooreKILLspam@spam@freeshell.org - http://wmoore.no-ip.info/ Free Email provided by: SDF Public Access UNIX System http://sdf.lonestar.org/ -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

I think you are taking on too big a project. To succeed, and get your paper in by the 22nd, you will need to look at an existing port of a real time operating system. Porting Linux will be too big a job for you. Concentrate on presenting a high quality paper on a realistic timeframe. That's what will get you the good grade and score points. After you do the paper you can start exploring a Linux port, but this is a big, tough job. I'm a Linux person myself. I'm just getting into PIC microcontrollers and I don't feel like I'm in the nursery at all. I know I'm in the nursery. One easy step at a time, there is so much to learn...I might even become as good as some of the others here, after several years... Bob Cochran Vishal Changrani wrote: {Quote hidden}> hi, > hi to all you big guys there..man ..after reading your questions and answers i feel i m still in nursery :( > anyway heres my question: > I want to develop (or rather 'Port') the linux kernel on to the Pic16f877. Now the reason I wish to do this is: > 1. I have to present a research paper due on april 22nd on the topic Real Time operating Systems: Case Study Microcontrollers. > 2. I think since both Linux and PIc are so very commercially successful in there respective domains that it would be good idea to combine them in some way. > 3. I love linux and the PIC and couldnt think of a better topic. > About the Real time part I think i will save that till later that is after I have finsihing porting Linux to the PIC (if I am able to do it i.e.) > > Now i went through a book - Building Embedded Linux Systems ..and it says that it isnt easy (not impossible ) though to port linux on to a 'less than 32 bit' microcontroller or microprocessor. So I am stuck now! since Microchip doesnt offers a 32 bit microcontroller. > Please suggest me something! anything! > > Thankyou > Bye > Vishal > > > --------------------------------- > Do you Yahoo!? > Yahoo! Small Business $15K Web Design Giveaway - Enter today > > -- > http://www.piclist.com hint: To leave the PICList > piclist-unsubscribe-requestKILLspammitvma.mit.edu > > -- Bob Cochran Greenbelt, Maryland, USA http://greenbeltcomputer.biz/ -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Well, I could easily assume that from where you sent this email it was April 1st when you sent it, but then I'd have to assume that the entire world enjoys the American April 1st holiday, which would then expose me as the sort of ameri-centric snob I've worked so long to hide. So I'll assume this is a serious request for help and feed the trolls, er, I mean expose some of the issues you'll run into when you design Linux into a PIC. First of all, don't let anyone tell you it can't be done. Anything is possible, though there are some tradeoffs: First, the PIC has no MMU. Heck, it doesn't really even have a fully manipulable stack. Linux typically requires at minimum an MMU, but some smart folks somewhere on the internet have cobbled together an embedded MMU-less version of linux. Find it and learn from them. Also find out what kind of life they lead, and expect to live that life for the remainder of your development period. Second, the PIC doesn't really have a fully capable ANSI C compiler. Don't worry, linux won't compile on just any old ANSI compiler anyway. Go ahead and pull out your copy of C18 and run it on a few linux source files. When it runs into a problem, comment that line out. You can always sort it out later. Don't let anyone fool you about linking - just copy all the object files into one big file (cp *.o linux.obj, for instance) and let the PIC worry about it. Then find a PIC with a large enough code space to hold the entire thing. Be aware, though, that since you commented out most of the code in an earlier step, you may need a larger PIC when you get all that sorted out. Thirdly, After realizing the futility of compiling linux directly for the PIC, take up the bright idea of creating an emulator that runs on the PIC. You can pick an existing core which already has emulators in C (such as ARM, MIPS, x86, HAL9000, etc) or make up your own. Tha advantage of picking one that exists is you don't have to create the C compiler as well. Code up the emulator for the PIC, and create external address/data busses for flash and ram. Look up the PCI spec and try to emulate that bus standard - it'll save you loads of time adding peripherals later. The performance of the system may be low (a few hundred instructions per second of emulated code) but be content in the fact that you were able to shoehorn Linux into an 8-bit microcontroller. All it'll take, really, is a bunch of elbow grease and headlamp fluid. Good luck! Keep us informed of your progress, ok? -Adam P.S. While the post is mainly in jest, the third option really would work. The PIC, after all, is Turing Complete, and in theory can perform any logical sequence of steps. I just can't see the educational value in doing it... Vishal Changrani wrote: {Quote hidden}>hi, >hi to all you big guys there..man ..after reading your questions and answers i feel i m still in nursery :( >anyway heres my question: >I want to develop (or rather 'Port') the linux kernel on to the Pic16f877. Now the reason I wish to do this is: >1. I have to present a research paper due on april 22nd on the topic Real Time operating Systems: Case Study Microcontrollers. >2. I think since both Linux and PIc are so very commercially successful in there respective domains that it would be good idea to combine them in some way. >3. I love linux and the PIC and couldnt think of a better topic. >About the Real time part I think i will save that till later that is after I have finsihing porting Linux to the PIC (if I am able to do it i.e.) > >Now i went through a book - Building Embedded Linux Systems ..and it says that it isnt easy (not impossible ) though to port linux on to a 'less than 32 bit' microcontroller or microprocessor. So I am stuck now! since Microchip doesnt offers a 32 bit microcontroller. >Please suggest me something! anything! > >Thankyou >Bye >Vishal > > >--------------------------------- >Do you Yahoo!? >Yahoo! Small Business $15K Web Design Giveaway - Enter today > >-- >http://www.piclist.com hint: To leave the PICList >.....piclist-unsubscribe-requestKILLspam.....mitvma.mit.edu > > > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

I agree with Adam : the best is to try to port ucLinux (the NO_MMU and NO_FPU version of Linux) to a PIC18 target (the only one to let you manage the hardware stack). Anyway don't forget the RAM space dedicated to the task descriptor is something like 2Kbytes with ucLinux, so you need a PIC with a lot of RAM space available to do it ! But if you have free time enough (one year probably) and a solution to have a PIC with many Kbytes free in the RAM space you can try to start the job.... Let us know when you get a first result. Xavier {Quote hidden}> Message du 01/04/04 07:20 > De : M. Adam Davis > A : @spam@PICLISTKILLspamMITVMA.MIT.EDU > Copie à : > Objet : Re: [PIC:] Want to port Linux to PIC16f877...Help needed from all you big guys > Well, I could easily assume that from where you sent this email it was > April 1st when you sent it, but then I'd have to assume that the entire > world enjoys the American April 1st holiday, which would then expose me > as the sort of ameri-centric snob I've worked so long to hide. > > So I'll assume this is a serious request for help and feed the trolls, > er, I mean expose some of the issues you'll run into when you design > Linux into a PIC. > > First of all, don't let anyone tell you it can't be done. Anything is > possible, though there are some tradeoffs: > > First, the PIC has no MMU. Heck, it doesn't really even have a fully > manipulable stack. Linux typically requires at minimum an MMU, but some > smart folks somewhere on the internet have cobbled together an embedded > MMU-less version of linux. Find it and learn from them. Also find out > what kind of life they lead, and expect to live that life for the > remainder of your development period. > > Second, the PIC doesn't really have a fully capable ANSI C compiler. > Don't worry, linux won't compile on just any old ANSI compiler anyway. > Go ahead and pull out your copy of C18 and run it on a few linux source > files. When it runs into a problem, comment that line out. You can > always sort it out later. Don't let anyone fool you about linking - > just copy all the object files into one big file (cp *.o linux.obj, for > instance) and let the PIC worry about it. Then find a PIC with a large > enough code space to hold the entire thing. Be aware, though, that > since you commented out most of the code in an earlier step, you may > need a larger PIC when you get all that sorted out. > > Thirdly, After realizing the futility of compiling linux directly for > the PIC, take up the bright idea of creating an emulator that runs on > the PIC. You can pick an existing core which already has emulators in C > (such as ARM, MIPS, x86, HAL9000, etc) or make up your own. Tha > advantage of picking one that exists is you don't have to create the C > compiler as well. Code up the emulator for the PIC, and create external > address/data busses for flash and ram. Look up the PCI spec and try to > emulate that bus standard - it'll save you loads of time adding > peripherals later. The performance of the system may be low (a few > hundred instructions per second of emulated code) but be content in the > fact that you were able to shoehorn Linux into an 8-bit microcontroller. > > All it'll take, really, is a bunch of elbow grease and headlamp fluid. > Good luck! Keep us informed of your progress, ok? > > -Adam > > P.S. While the post is mainly in jest, the third option really would > work. The PIC, after all, is Turing Complete, and in theory can perform > any logical sequence of steps. I just can't see the educational value > in doing it... > > Vishal Changrani wrote: > > >hi, > >hi to all you big guys there..man ..after reading your questions and answers i feel i m still in nursery :( > >anyway heres my question: > >I want to develop (or rather 'Port') the linux kernel on to the Pic16f877. Now the reason I wish to do this is: > >1. I have to present a research paper due on april 22nd on the topic Real Time operating Systems: Case Study Microcontrollers. > >2. I think since both Linux and PIc are so very commercially successful in there respective domains that it would be good idea to combine them in some way. > >3. I love linux and the PIC and couldnt think of a better topic. > >About the Real time part I think i will save that till later that is after I have finsihing porting Linux to the PIC (if I am able to do it i.e.) > > > >Now i went through a book - Building Embedded Linux Systems ..and it says that it isnt easy (not impossible ) though to port linux on to a 'less than 32 bit' microcontroller or microprocessor. So I am stuck now! since Microchip doesnt offers a 32 bit microcontroller. > >Please suggest me something! anything! > > > >Thankyou > >Bye > >Vishal > > > > > >--------------------------------- > >Do you Yahoo!? > >Yahoo! Small Business $15K Web Design Giveaway - Enter today > > > >-- > >http://www.piclist.com hint: To leave the PICList > >KILLspampiclist-unsubscribe-requestKILLspammitvma.mit.edu> > > > > > > > > > > > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads