On Sat, Dec 08, 2012 at 05:17:06PM -0800, Joseph Areeda wrote: > I'm pretty sure there are Debian ports for ARM including RasberryPi. I am more interested in getting the SL userland running on the ARM machines. K.O. > > Here's an interesting project out of the UK > http://www.southampton.ac.uk/~sjc/raspberrypi/ where the guy built a > 64 node cluster using Lego for the supports. > > I'm also sure it was a lot of work like others have mentioned. > > Perhaps when the upstream providers get the kernel and the drivers > going in the Fedora and RedHat branches we'll see SL7 or 8 available > for ARM also. > > Joe > > On 12/07/2012 11:27 AM, Konstantin Olchanski wrote: > >Please do not confuse 3 separate issues: > > > >1) Linux userland: this is pretty much universal and will > > run on any CPU as long as you have a cross-compiler > > and as long as the "autoconf" tools do not try too hard > > to prevent you from cross-compiling the stuff. > > > >2) Linux kernel: is also pretty much universal and assumes > > very little about the CPU. There *is* some assembly code > > that needs to be ported when you move between CPUs (say > > from hypothetical SuperARM to hypothetical HyperARM). I believe > > current versions of Linux kernel have this support for > > all existing ARM CPU variations. > > > >3) Linux device drivers: in the PC world devices are standardized > > around the PCI bus architecture (from the CPU, PCIe looks like PCI, > > on purpose) and most devices drivers are universal, so if you > > have a PCI/PCIe based ARM machine with PC-type peripherals ("South Bridge", > > ethernet, video, etc), you are good to go. If you have an ARM machine > > with strange devices (i.e. the RaspberryPI), you have to wait > > for the manufacturer to release the specs, then you can write > > the drivers, then you can run Linux. Rinse, repeat for the next > > revision of the CPU ASIC (because they moved the registers around > > or used a slightly different ethernet block). It helps if you have > > some standardized interfaces, for example on the RaspberryPI you have > > standard USB, so you can use "all supported" USB-Wifi adapters right away. > > > >4) boot loader: is different for each type of machine, each type > > of boot device media. period. (Even on PCs there is no longer any > > standard standard - some use old-school BIOS booting, others use EFI boot, > > some need BIOS/ACPI help, some do not). > > > >This makes it 4 issues, if you count the first (linux userland) non-issue. > > > > > >K.O. > > > > > >On Fri, Dec 07, 2012 at 01:01:36PM -0600, SLtryer wrote: > >>On 10/23/2012 12:37 PM, Konstantin Olchanski wrote: > >>>An "ARM platform" does not exist. > >>> > >>>Unlike the "PC platform" where "PC hardware" is highly standardized > >>>and almost any OS can run on almost any vendor hardware, > >>>the "ARM platform" is more like the early Linux days where instead > >>>of 3 video card makers there were 23 of them, all incompatible, > >>>all without Linux drivers. If you had the "wrong" video card, > >>>too bad, no soup for you. > >>> > >>>In the ARM world, there is a zoo of different ARM processors, > >>>all incompatible with each other (think as if each Android device > >>>had a random CPU - a 16-bit i8086, or a 32-bit i386, or a 64-bit i7 - > >>>the variation in capabilities is that high). > >>> > >>>Then each device contains random i/o chips connected in it's own > >>>special way - there is no PCI/PCIe bus where everything is standardized. > >>>There are several WiFi chips, several Bluetooth, USB, etc chips. Some > >>>have Linux drivers, some do not. > >>> > >>>As result, there is no generic Linux that will run on every ARM machine. > >>Not to be argumentative, but I always believed that the advantage of > >>*nix* was that it could be ported to numerous platforms, regardless > >>of hardware. You even mention the "early Linux days," when there > >>was little or no standardization of PC hardware. Yet, the platform > >>didn't disappear from use simply because there might have been > >>porting issues, most of which were caused more by proprietary > >>secrets and hardware defects than the ever-present fact of diversity > >>of hardware. > >> > >>But one could make the same argument even today: That there are > >>many different CPU platforms, e.g., and that they are not > >>standardized. One example I am thinking of is the Intel v. Amdahl > >>CPU compatibility issue. Even though most of the Linux system will > >>run on either without modification, there are still some unique > >>issues to each of them; from having worked and studied VirtualBox, > >>there are differences in how each manufacturer chose to implement > >>the ring structure that permits virtualization to work as nicely as > >>it does on these platforms. For the most part, they are compatible, > >>but the kernel developers have to be aware of certain implemention > >>issues, including a bug in the Intel CPU platform that requires a > >>VirtualBox workaround (for optimizing the code or something; I > >>forget). > >> > >>And this is in addition to Linux supporting umpteen different > >>processing platforms besides the x86 types. New hardware appears > >>constantly, and some Linux user somewhere wants to use it on their > >>system. I feel that variety of hardware and variation in hardware > >>implementation is a fact, and a main reason why Linux and Unix are > >>so powerful and ubiquitous. > >> > >>Now I just hope no one will hold me to this and insist that I > >>actually port Linux to all these different hardware configuration! > >>I'm not signing up; I'm just pointing out what I think is reality. -- Konstantin Olchanski Data Acquisition Systems: The Bytes Must Flow! Email: olchansk-at-triumf-dot-ca Snail mail: 4004 Wesbrook Mall, TRIUMF, Vancouver, B.C., V6T 2A3, Canada