Re: Learning things
> I'm working on trying to teach myself C and was wondering if you had any > kernel specific recommendations. I started the eudyptula challenge but > so far it seems to be mostly learning the standards and whatnot. Are > there any kernel/C books or online tutorials you guys think would help? As others mention, using the Linux kernel to come up to speed with C is the wrong approach. If you have a strong desire to learn kernel programming concepts while coming up to speed on C, I would suggest getting the latest book on Xinu, buying an Intel Galileo board and working your way through that book. Xinu is what I cut my teeth on 25 years ago and I remember it being a terrific learning environment. Xinu is not Linux (or Unix), but for starting at the ground level all the concepts will map over when you are ready to tackle Linux kernel work. Information for Xinu can be found here: http://www.xinu.cs.purdue.edu/ Good luck on your learning... Mike Thompson On Mon, Apr 6, 2015 at 10:17 AM, Greg KH wrote: > On Mon, Apr 06, 2015 at 10:43:46AM -0700, Joris Bolsens wrote: > > Hey list, > > > > I'm working on trying to teach myself C and was wondering if you had any > > kernel specific recommendations. I started the eudyptula challenge but > > so far it seems to be mostly learning the standards and whatnot. Are > > there any kernel/C books or online tutorials you guys think would help? > > Don't learn C with kernel code, please take a few years really learning > the language in userspace, with one of the other thousands of other > userspace programs that could use help that are written in C. > > Good luck, > > greg k-h > > ___ > Kernelnewbies mailing list > Kernelnewbies@kernelnewbies.org > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Looking for ARM SoC porting guidelines
Hi Luca, I need to get back to the project. I got pulled away from the project during the holidays and haven't had the time to make progress since that time due to family and work obligations. I'm currently working on getting a client to help pay for my time working on this project. If successful, that will help get things moving much, much faster. Crossing my fingers that they go for it. At least now I have both N32905 and N32926 development boards so I can try to get a modern kernel for both versions of the SoC. Mike On Sun, Feb 1, 2015 at 1:15 AM, Luca Ceresoli wrote: > Dear Mike, > > Mike Thompson wrote: > [...] > >> I'm still waiting for my N32926 hardware to arrive to begin a port for >> it. Given the work I've done with the N32905 and the similarity between >> the two chips at the basic level, I don't anticipate it taking more than >> a few days to get it going. I'll post back here when I have something >> to try. At a minimum it would include the clock framework, clock >> source, interrupt driver, UART driver and other basic stuff. >> >> Oh, and... any plans for supporting the H.264 decoder on the N32926? >> >> Well, for now I'm working on the basics and the first tier of drivers to >> the system so it can boot from NOR/NAND flash, SD cards and have basic >> USB connectivity. I already have these items on the N32905. I don't >> have any specific plans beyond that for the N32926, but we'll see. My >> specific interest is in the lower-end N32905 because of the opportunity >> for the chip in the toy markets and a $3 Linux capable single chip >> system is really cool :-). >> > > Any news on your project? There seem to be no more commits since several > weeks on your github repository... > > -- > Luca > ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Looking for ARM SoC porting guidelines
On Fri, Nov 14, 2014 at 9:10 AM, Luca Ceresoli wrote: > Very interesting. I just started a project using the Nuvoton N32926, > and mainline support in a recent kernel would be very, very > interesting. I'd be glad to join your effort by testing your code, and > possibly contributing. > > What bootloader are you using? AFAIK Nuvoton does not provide any sort > of U-Boot, barebox or any other open source bootloader. > Correct. For right now, I'm using the proprietary Nuvoton bootloaders which are kind of a mess in terms of having to use the 15 year old ARM Development Suite software to build. I have a simple script which converts a Linux Image file and device tree binary into a conprog.bin file that the Nuvoton can boot with from the existing bootloaders. Nuvoton is switching to a newer Keil based development environment for their proprietary bootloader, but that's not a whole lot better. My hope is to get some sort of U-boot running by adapting pieces of the proprietary bootloader, but that's a secondary priority relative to just getting basic kernel functionality running. Do you have any working configuration for the N32926? Boot+UART, I don't > expect much at this early stage, but I'd like to test it as soon as you > have one. > I'm still waiting for my N32926 hardware to arrive to begin a port for it. Given the work I've done with the N32905 and the similarity between the two chips at the basic level, I don't anticipate it taking more than a few days to get it going. I'll post back here when I have something to try. At a minimum it would include the clock framework, clock source, interrupt driver, UART driver and other basic stuff. Oh, and... any plans for supporting the H.264 decoder on the N32926? > Well, for now I'm working on the basics and the first tier of drivers to the system so it can boot from NOR/NAND flash, SD cards and have basic USB connectivity. I already have these items on the N32905. I don't have any specific plans beyond that for the N32926, but we'll see. My specific interest is in the lower-end N32905 because of the opportunity for the chip in the toy markets and a $3 Linux capable single chip system is really cool :-). Mike ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Looking for ARM SoC porting guidelines
On Thu, Nov 13, 2014 at 12:40 AM, Maxime Ripard < maxime.rip...@free-electrons.com> wrote: > > As a guide, I've been using other ARM SoCs for examples and a number of > > very useful presentations on ARM SoC support from the Free Electron > folks. > > Although presentations such as the "ARM SoC Linux Support Check-list" are > > very useful, they don't go into much detail. > > > > My question is two fold. Is there detailed information of all the things > > that need to be covered in the code to introduce a new ARM SoC into the > > kernel? > > Usually "enough so that it boots", which means: timers, interrupts, > UARTs, and that's pretty much it. > > Any additional feature is of course welcome, but I'd suggest to just > post that for the first set of patches. There will probably > significant changes to make to your base drivers (and I would include > clocks and pinctrl into these drivers), and these will impact any > further developments. You don't want to have too much dependency :) > > Start small, then build on top of what's accepted. > OK, that is pretty much from what I expected. I'll begin this process soon as I have added similar base support for the N32926 which is a bigger brother to the N32905. I figure it's best to lay the foundation for multiple chips in the Nuvoton N329 family from the start. I've been using the iMX23 and iMX26 SoC support as the model for code placement, naming and such. These chips are useful in the way they share drivers similar to what I would like to do. Are these SoCs known to be following current best ARM SoC practices for me to follow in their path? Concerning how I should arrange my code in a git repository, currently everything is in a single branch. I guess I'll want to peel out just the minimal set of drivers from which I'll submit patches and then do the work on the more advanced SoC drivers in another set of branches so everything isn't all mixed together. > Then, is there a description of how I start to go about contributing > > support for this chip into the Linux kernel? I honestly don't really > > know where to begin. > > Like I said, send the minimum amount of patches to have Linux boot an > initramfs on your SoC. Apart from that, there is nothing out of the > ordinary on how to submit patches, everything is detailed in > Documentation/SubmittingPatches. Basically, it will involve sending > patches to the linux-arm-kernel mailing list and the ARM SoC kernel > maintainers. Make sure that everything has no warning in > scripts/checkpatch.pl, and you're good to go. > > Maxime > Got it. Hopefully I'll start with the first set of patches within in the next few weeks and cross my fingers I'm not chased away with a stick for being such a newbie :-). Before submitting the first set of patches, would it be useful for me to post a link to them here on this mailing list so someone could look them over as a sanity check before a submission to the linux-arm-kernel mailing list? I'm a bit nervous about making a good first impression. Mike ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Looking for ARM SoC porting guidelines
I'm working on a port the latest Linux kernel to a Nuvoton N32905 - a very inexpensive ARM9 based SoC similar to the Freescale iMX23 in many respects. My hope is that my code for this SoC will eventually reach the mainline kernel, but the whole process a fairly daunting task to a kernel newbie such as myself. I do have a six year old port of the 2.6.35 kernel to this SoC to help as a reference, but it's pretty much a rewrite to support devicetree, the common clock framework, and a myriad of changes needed to get a new SoC supported in the mainline kernel. Not to mention all the 2.6.35 code added for this chip isn't even close to the coding standards for the Kernel. So far I got the 3.17 kernel running pretty well the baseline peripherals such as clocks, interrupt controller, UART, GPIO & pin muxing along with hire level peripherals such as MMC/SD card support, MTD NAND and NOR flash and USB host support. As a guide, I've been using other ARM SoCs for examples and a number of very useful presentations on ARM SoC support from the Free Electron folks. Although presentations such as the "ARM SoC Linux Support Check-list" are very useful, they don't go into much detail. My question is two fold. Is there detailed information of all the things that need to be covered in the code to introduce a new ARM SoC into the kernel? Then, is there a description of how I start to go about contributing support for this chip into the Linux kernel? I honestly don't really know where to begin. Any advice or pointers would be sincerely appreciated. Mike Thompson BTW, my git reposity for this SoC is: https://github.com/mpthompson/linux/tree/n329 ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
