1 U-Boot FDT Overlay usage (without FIT images)
2 =============================================
4 FDT overlays are now available for use even without FIT images.
5 It is not as automagic as with FIT images though and require a few
8 1. Figure out where to place both the base device tree blob and the
9 overlay. Make sure you have enough space to grow the base tree without
12 => setenv fdtaddr 0x87f00000
13 => setenv fdtovaddr 0x87fc0000
15 2. Load the base blob and overlay blobs
17 => load ${devtype} ${bootpart} ${fdtaddr} ${bootdir}/base.dtb
18 => load ${devtype} ${bootpart} ${fdtovaddr} ${bootdir}/overlay.dtb
20 3. Set it as the working fdt tree.
24 4. Grow it enough so it can 'fit' all the applied overlays
28 5. You are now ready to apply the overlay.
30 => fdt apply $fdtovaddr
32 Please note that in case of an error, both the base and overlays are going
33 to be invalidated, so keep copies to avoid reloading.
36 pantelis.antoniou@konsulko.com