On Fri, Apr 29, 2011 at 08:37:24PM -0400, Nicolas Pitre wrote: > On Fri, 29 Apr 2011, Grant Likely wrote: > > > diff --git a/Documentation/devicetree/booting-without-of.txt > > b/Documentation/devicetree/booting-without-of.txt > > index 50619a0..31d7e8a 100644 > > --- a/Documentation/devicetree/booting-without-of.txt > > +++ b/Documentation/devicetree/booting-without-of.txt > [...] > > +1) Entry point for arch/arm > > +--------------------------- > > + > > + There is one single entry point to the kernel, at the start > > + of the kernel image. That entry point supports two calling > > + conventions. A summary of the interface is described here. A full > > + description of the boot requirements is documented in > > + Documentation/arm/Booting > > + > > + a) ATAGS interface. Minimal information is passed from firmware > > + to the kernel with a tagged list of predefined parameters. > > + > > + r0 : 0 > > + > > + r1 : Machine type number > > + > > + r2 : Physical address of tagged list in system RAM > > + > > + b) Entry with a flattened device-tree block. Firmware loads the > > + physical address of the flattened device tree block (dtb) into r2, > > + r1 is not used, but it is considered good practise to use a valid > > + machine number as described in Documentation/arm/Booting. > > + > > + r0 : 0 > > + > > + r1 : Valid machine type number. When using a device tree, > > + a single machine type number will often be assigned to > > + represent a class or family of SoCs. > > + > > + r2 : physical pointer to the device-tree block > > + (defined in chapter II) in RAM. Device tree can be located > > + anywhere in system RAM, but it should be aligned on a 64 > > bit > > + boundary. > > + > > + The kernel will differentiate between ATAGS and device tree booting by > > + reading the memory pointed to by r1 and looking for either the flattened > > s/r1/r2/
Good catch. Thanks. g. _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
