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Re: [microblaze-uclinux] Setting up for Microblaze work.



Dr. Johann Pfefferl wrote:
> Hello,
>
> according to the initramfs filesystem I can report you the following.
> For me it works. Unpacking it is slow (~ 11 seconds for 800kB @ 50MHz)
> but it works. Do you have a /init in the root of the filesystem? If not
> the initramfs would never be accepted as rootfs. The other option is to
> specify the rdinit=/whatever_program command parameter to the linux
> kernel. Please note that you have to use "rdinit=..." and not "init=..."
> to specify the init process for a initramfs based root filesystem.
>
> The good thing with initramfs is that you don't need any other normal
> filesystem (romfs, ramfs, ext2, ...) compiled into the kernel and it's
> writeable.
>
>   
    Thanks;
          I am glad to here it is working for you. Initramfs is an
integral part of our Linux framework.
   
          I am not yet at the point of trying what I have on hardware.
          For the moment I am the "OS" guy. I do need to get my hands
dirty with FPGA firmware, but I have not
          had time yet. We have a new line of Virtex5 based boards that
have had their  first short production run.
          But I do not have one yet. We also have older V4FX boards that
someone is supposed to get me firmware with a MicroBlaze ASAP.

          In the meantime I am trying to merge the PPC Linux BSP I
already have for the old boards with the uCLinux MicroBlaze port.
          At this point I can compile a kernel. That is a big step.

          I did manage to move all the CONFIG_XILINX_XXXX parameters out
of the Linxu kernel.config and into an xparameter type include file.
         
          I am still trying to sort out whether and why  MMUless cpu 
can not use an ELF file.

          I fully appreciate the usefullness of initramfs. It is a key
part of my PPC Linux, and despite weak documentation, I am very happy
with and fairly
          familiar with initramfs.
          But I do not seem to be getting my kernel compile to build and
concatenate the initramfs data. But your success means it is doable, and
I will just
          push forward until I beat it.




   

         
         


> Hope this helps,
>   Hans
>
> David H. Lynch Jr <dhlii@xxxxxxxxxxx> wrote:
>   
>>     Being a stuborn (not so) old coot, I have started trying to setup to
>> provide a MicroBlaze Linux BSP for current and Future Pico boards.
>>
>>     I have:
>>
>>           Patched my development tree (based on Linux's linux-2.6.git
>> from kernel.org) with the uClinux linux-2.6.20-bigpatch.
>>        There were a few m68k issues I chose to ignore  - I am not doing
>> any 68k work, otherwise all these patches either went in smoothly
>>     or will only minor fixes.
>>
>>           Patched my development environment with the collection of
>> Linux-2.6.19 Microblaze patches from petalogics development site (thank you)
>>     This was somewhat more difficult as the patches were against the
>> petalogic uClinix development tree not a stock Linux source tree with
>> uClinux patches.
>>     This required a number of fixes, but nothing that looked scary, evil
>> or appeared to have a high probability of biting me in the ass later.
>>
>>     Installed the microblaze-uclinux crosscompilers also from petalogix.
>>
>>     put together a build script to run make specifying a microblaze
>> target and the microblaze crosscompiler.
>>
>>     Actually built the sucker - alright it took several hours to work
>> through a small collection of problems that mostly seem to stem from
>> differences between 2.6.19 and 2.6.21.rc#
>>
>>     Now I have a small collection of questions ?
>>
>>     uClinux seems to be partial to flat format files ? Is there some
>> reason the absence of an MMU makes loading an elf file difficult ?
>>     Our bootloader already handles elf files. Must I use flat files on a
>> MicroBlaze ?
>>
>>     There is a huge collection of CONFIG_XILINX_ macros inside the
>> .config file that seem to correspond to xparameters.h.
>>     First I can not seem to kill the ones I am not using, and second
>> don't these really belong in a header file not .config ?
>>     How and  where do I kill them off ?
>>
>>     I am explicitly using an initramfs build. I am trying to use the
>> standard Linux build facilities for that.
>>     As best as I can tell the kernel binary that gets built does not
>> include my initramfs files.
>>     Any clue what I need to change (inside arch/microblaze ?) to fix this ?
>>
>>
>>     
>
>   


-- 
Dave Lynch 					  	    DLA Systems
Software Development:  				         Embedded Linux
717.627.3770 	       dhlii@xxxxxxxxxx 	  http://www.dlasys.net
fax: 1.253.369.9244 			           Cell: 1.717.587.7774
Over 25 years' experience in platforms, languages, and technologies too numerous to list.

"Any intelligent fool can make things bigger and more complex... It takes a touch of genius - and a lot of courage to move in the opposite direction."
Albert Einstein

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