I start working on OE microblaze support and is kind of tricky,
there are several efforts on updating gcc, binutils, glibc, and
I’m integrating from Xilinx repos since they are the most updated
versions available for microblaze; Still glibc build is failing
due to a mis configuration in binutils; So I have to options,
add a prebuild toolchain in OE or fix glibc; the exact error occurs at
linking the final objects ld complains about “unsupported emulation” to
workaround this there’s an run-time variable that can be used to set the
emulation mode `LDEMULATION` but fails in a later stage, so the error
roots are in binutils configuration.
OE changes are stored at http://gitorious.org/oe-microblaze/oe-microblaze
Xilinx provide me some target platform (ML405, ML507), for testing/validation
one of my concerns was import taxes from Mexican customs, but I provide the
paperwork to claim professional development usage to be extent of pay taxes,
well that’s one good thing of Mexican custom regulations, and I didn’t pay a
single dollar :). Thanks John and Grant for making possible to have some
hardware at home, that would free the only single ML507 board from my
From Google every student is still waiting on welcome package and payment
cards, they are estimated to be delivered in two weeks, well lets wait and
see if Google is generous and send us a cool nexus one ;).
* Important this is an experimental and ongoing project
After several kernel panics and machine exceptions I’m now been able to boot Linux on Xilinx Ml507 development platform; This board combines a Powerpc 440 cpu with standard peripherals like ethernet, serial ports, DVI, sata, etc. plus a large re configurable area where custom hardware can be developed and interconnected to the main CPU via the processor bus.
Xilinx provides a development environment but the Linux board support is pretty old since most vendors don’t support this board any more. Since there was previous work on Openembedded supporting previous version of this platform (Powerpc 405 based) adding support for Ml507 board is simple.
Most of the problems that arise in my initial efforts was setting the correct Kernel options, erroneous hardware configurations, missing dev nodes in final root file system. Christopher ‘Embedded Linux premier’ book prove to be a great reference also many of the xilinx application notes that I have to check to learn about the gotchas.
At my github repo there’s the result hardware project http://github.com/aalonso/xilinx-ml507
there’s two branches the master branch holds the reference design as described in the application note  the second branch adds the device tree infrastructure to generate the hardware descriptor file (*.dts) that the Kernel uses to find out about the resources available in the target system.
I push some patches to Openembedded developers list to add the corresponding support, this was important in order to simplify the process of replicating my developing environment for new team members in the lab at my faculty. Some of the problems that I still have is that ethernet device is not working, I have read some applications notes that mention that the driver provided in the Linux kernel only works in certain configuration mode; Alternative I can use the soft-ethernet hardware module since is reported that works.
Soon I will post a quick howto with the steps to boot Linux, for the moment
On the next week I’m going to give a crash course using Openembedded at my faculty, and also seriously thinking that my current project is a good candidate for participating in Google summer of code which is right at the corner.
 Using U-Boot with the Xilinx ML507 Evaluation Platform