root driver is at device tree offset 0 (the root node, '/'), and its
children are the children of the root node.
+In order for a device tree to be valid, the content must be correct with
+respect to either device tree specification
+(https://www.devicetree.org/specifications/) or the device tree bindings that
+are found in the doc/device-tree-bindings directory. When not U-Boot specific
+the bindings in this directory tend to come from the Linux Kernel. As such
+certain design decisions may have been made already for us in terms of how
+specific devices are described and bound. In most circumstances we wish to
+retain compatibility without additional changes being made to the device tree
+source files.
Declaring Uclasses
------------------
For pre-relocation we simply call the driver model init function. Only
drivers marked with DM_FLAG_PRE_RELOC or the device tree
'u-boot,dm-pre-reloc' flag are initialised prior to relocation. This helps
-to reduce the driver model overhead.
+to reduce the driver model overhead. This flag applies to SPL and TPL as
+well, if device tree is enabled there.
It is possible to limit this to specific relocation steps, by using
the more specialized 'u-boot,dm-spl' and 'u-boot,dm-tpl' flags
-in the devicetree.
+in the device tree node. For U-Boot proper you can use 'u-boot,dm-pre-proper'
+which means that it will be processed (and a driver bound) in U-Boot proper
+prior to relocation, but will not be available in SPL or TPL.
Then post relocation we throw that away and re-init driver model again.
For drivers which require some sort of continuity between pre- and
projects / platform / kernel / u-boot.git / blobdiff