Re: Microblaze uClibc

On Mon Mar 31, 2003 at 10:49:25AM +1000, John Williams wrote:
> Hi folks,
> 
> This is my first post to the uClibc list.  I've just completed the core 
>  kernel port for uClinux 2.4.x onto the Xilinx Microblaze, a 32 bit 
> RISC softcore microprocessor that runs on Xilinx FPGAs.  Next stop is 
> creating uClibc support for microblaze.

I saw your recent post to the uclinux-dev list.  very cool stuff.  

> As part of the uClinux CVS distro provided by Snapgear, I have the 
> uClibc source tree etc, and am wondering the best way to go about 
> introducing a new arch into uClibc.

Easy enough to do.  Step one is to create a new
uClibc/libc/sysdeps/linux/microblaze directory and populate it
per the content of the other supported arches (arm, x86, v850,
etc), adjusted as necessary for the specifics of your  Xilinx
Microblaze architecture.

> The microblaze kernel port is based heavily on the v850 port, and I plan 
> to do the same for the uClibc support.  I've duplicated the 
> v850-specific stuff in the uClibc tree and mapped it across for 
> microblaze, like the setjmp/longjmp, and so on.  I've also created a 
> microblaze.config file in uClibc/extra/Configs.

Sounds good

> By doing the above, make gets part way into uClibc but fails primarily 
> because libgen.h is not in my gcc include path (oh, I'm working under 
> Cygwin BTW).  I could hack the Makefile but I don't think this is the 
> right way to go.

Hmm.  What _is_ in the path specified on the gcc command line?

It is supposed to pull in the uClibc/include directory when
compiling, but I've honestly never tried to make uClibc compile
under Cygwin so I can't say what problems that may or may not be
adding.

> Am I going about this the right way, or do I have to go "higher" than 
> this and use buildroot etc?  I searched the archive to see if Miles 

nope.  That is for building thing using uClibc, which isn't going
to be relevant till you have a basic port of uClibc compiling....

> (Bader) had asked any of the same questions when he did the v850 port a 
> couple of years back, but didn't find anything particularly 
> enlightening.  Miles are you still listening here?  Any words from the wise?
> 
> Any assistance greatly appreciated.

I generally hang out on IRC most work days, so if tomorrow
(monday) you care to drop by #uclibc (which lives on
irc.freenode.net) I'll be happy to help.  

Of course if you have specific questions, asking them on the
mailing list is best, so they can be archived and thereby help 
the next poor soul that tries to do a port...

The good news is (except for the cygwin specfic issues you may
have) porting uClibc is pretty easy, especially since you will
not need to port the shared lib loader for a mmu-less cpu,

 -Erik

--
Erik B. Andersen             http://codepoet-consulting.com/
--This message was written using 73% post-consumer electrons--