[microblaze-uclinux] uCLinux VS Linux

[Greg Miller <apco25@xxxxxxxxx>]

All,

 

here is a message that I sent to John. Since he said people may be interested in this, I am forwarding to this group. Feel free to chime in anyone. I know this has been discussed here before as well.

 

John, to answer your question below I am using open-source distribution 2.4.30-pre1 from the MV website. (It is not the supported version however).

I used Crosstool to build the ppc cross compiler.

 

Here is what I want to do:

1). mount a drive on ddr like uCLinux does (i.e. not have to use nfs or the ACE).

2). Build in Busybox like uCLinux

3). build a .bit file like uCLinux (not .elf)

4). Get MTD to work with flash.

 

Basically, I want it to be very similar to uCLinux except for the running on the PPC in V4 not on MB.

 

John says below maybe just compile uCLinux for PPC. John, what did you do to get that to work? I could try it.

 

Thanks.

John Williams <jwilliams@itee.uq.edu.au> wrote:

> Date: Tue, 07 Jun 2005 14:46:34 +1000
> From: John Williams <jwilliams@itee.uq.edu.au>
> To: Greg Miller <apco25@yahoo.com>
> Subject: Re: uCLinux VS Linux
>
> Hi Greg,
>
> Greg Miller wrote:
>
> > I wanted to ask this of you off line since it's more of a Linux question 
> > than uCLinux. I am compiling Linux for the PPC and I want to have the 
> > root filesystem reside in DDR just like uCLinux does. Linux seems to 
> > offer NFS and file systems on the SYS ACE. I think you did this or know 
> > about it for uCLinux VS Linux and was wondering if you can give me some 
> > history/guidence on this subject.
>
> Which Linux distribution are you using for your PPC work? MontaVista, 
> or Denx' ELDK, ???
>
> I've experimented with building PPC kernels from within the 
> uClinux-dist, so it uses exactly the same build processes!
>   as a
>  typical 
> uClinux build. However at that time I had no hardware to test it on, so 
> didn't get much further than that.
>
> However, I suspect that it will only be a little bit of work to do what 
> you are attempting.
>
> > I don't need details (unless you want to give them to me) because I know 
> > you are busy. However, I am not afraid to read, so if you have 
> > informational links that would be great.
>
> Hmm, don't know any links off the top of my head. Essentially you need 
> to look at how the PPC kernel handles mounting the root filesystem, then 
> map that across to use the ROMFS/CRAMFS mechanism used in uClinux-land.
>
> Here's a couple of articles that talks about how it's done in uClinux:
>
> http://www.ucdot.org/article.pl?sid=03/01/11/1049210&mode=thread
>
> http://www.ucdot.org/archive/deep/deeply-embedded-linux.html
> (maybe)
>
> On the PPC side, I don't have anything of value - jsut use the source 
> and of cou!
>  rse
>  google! :)
>
> > One other thing is how it was done to create a .bit file from the 
> > .elf... Similar issue does not seem to be offered in the Linux release 
> > (directly).
>
> Again, not sure which linux release you are refering to. You can get 
> the latest MontaVista PPC tree from www.penguinppc.org - but I am not 
> sure of their approach.
>
> Convergence between the mb-uclinuxc and PPC-linux is on my roadmap, but 
> we aren't expecting any signficant results for a few months yet, so you 
> probably don't want to wait. Am happy to discuss the subject with you 
> if you wish.
>
> Also, feel free to raise these issues on the mb-uclinux list - the 
> mb/ppc crossover is probably of wider interest than you might think...
>
> Cheers,
>
> John