device tree info

device-tree.md

@@ -0,0 +1,41 @@
+# Device tree
+
+`platform_device.c` together with its kernel and QEMU forks contains a minimal runnable example.
+
+Good format descriptions:
+
+- <https://www.raspberrypi.org/documentation/configuration/device-tree.md>
+
+Minimal example
+
+    /dts-v1/;
+
+    / {
+        a;
+    };
+
+Check correctness with:
+
+    dtc a.dts
+
+Separate nodes are simply merged by node path, e.g.:
+
+    /dts-v1/;
+
+    / {
+        a;
+    };
+
+    / {
+        b;
+    };
+
+then `dtc a.dts` gives:
+
+
+    /dts-v1/;
+
+    / {
+            a;
+            b;
+    };