On Mon, May 17, 2010 at 8:54 PM, Jeremy Kerr <[email protected]> wrote: > Hi all, > > As we're getting closer to device tree support on ARM, I'd like to get some > input on our proposed boot interface. > > Basically, I'd like to define how we pass the device tree from the bootloader > to the kernel. > > My current method of doing this is through a new atag. It looks like this: > > /* flattened device tree blob pointer */ > #define ATAG_DEVTREE 0x5441000a > > struct tag_devtree { > __u32 start; /* physical start address */ > __u32 size; /* size of dtb image in bytes */ > }; > > With ATAG_DEVTREE, we keep the existing boot interface the same (ie, machine > number in r1, atags pointer r2).
For the reference of those new to this discussion, here is a link to the previous thread and the link to the draft boot interface document. http://www.mail-archive.com/[email protected]/msg00884.html http://devicetree.org/Boot_Environment [...] > - We are now potentially carrying data in two different places - atags and > the device tree. For example, the physical memory layout and kernel command > line may be present in both. I've tried to explicitly addresses this in the draft document. the DT blob always supersedes ATAG information. Cheers, g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
