On Thu, 2012-01-26 at 21:19 +0100, Zygmunt Krynicki wrote:
With Pawel Moll's VExpress device tree support patches on top of mainline, we can produce a single kernel config and a set of device trees which allow booting on all the A15-based model variants.
About device trees, does the simulator need an explicitly provided device tree (in a way we currently provide the kernel image and ramdisk) or is the dt table built into the image?
Currently the simplest way of booting a DT kernel on a model is to use the CONFIG_ARM_APPENDED_DTB=y and CONFIG_ARM_ATAG_DTB_COMPAT=y and simply feed the model with concatenated zImage+DTB. Tested last night. One hint: do _not_ use earlyprintk on models - current version of DEBUG_LL in my DT4VE patches can fail in such case.
I'm planning to modify the boot.S to be able to create an AXF file from separate kernel and DTB (will happen next week, if anyone wants to try it let me know and I'll notify you when it's ready), but the long term (hopefully next FM release, mid-this-year) plan is to teach the model environment about Linux and DT so no wrapper would be necessary at all.
Cheers!
Paweł