On Mon, Dec 10, 2012 at 05:54:36PM -0600, Connie Sieh wrote:
> On Mon, 10 Dec 2012, Konstantin Olchanski wrote:
> 
> >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.
> >
> 
> There is a RHEL 6 rebuild for "arm" called RedSleeve.
> http://www.redsleeve.org .
> 


Yes, thanks. One difficulty I expect is with no "cross-install" capability when I can
use a 2nd computer (x86) to "cross-install" ARM RPMs into an ARM boot media.

If you do frequent cross-compilation, you would agree with me that lack of cross-install is so silly.

I think the expectation is that I have an ARM machine big enough
to run the SL installer. At least the text-mode installation is still
there and there is no requirement of a working ARM X11 server on
whatever funny ARM machine I happen to have.


K.O.



> -Connie Sieh
> 
> >
> >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