zephyr-build: YAML-based augment code

Instead of hardcoding all of the augments in the code, put these
augments into a data structure.  Load the actual rules from a yaml file
(with a future ability to extend this with per-app or per-module defined
augments.

Convert all of the existing hardcoded augment rules into the initial
augment file.

Author: d3zd3z

CMakeLists.txt

@@ -4,6 +4,9 @@
 
 set(RUST_MODULE_DIR "${CMAKE_CURRENT_LIST_DIR}" CACHE INTERNAL "")
 
+# Initially, we just have a single DT augment file.
+set(DT_AUGMENTS "${CMAKE_CURRENT_LIST_DIR}/dt-rust.yaml" CACHE INTERNAL "")
+
 # Zephyr targets are defined through Kconfig.  We need to map these to
 # an appropriate llvm target triple.  This sets `RUST_TARGET` in the
 # parent scope, or an error if the target is not yet supported by
@@ -134,6 +137,7 @@ INCLUDE_DIRS = \"${include_dirs}\"
 INCLUDE_DEFINES = \"${include_defines}\"
 WRAPPER_FILE = \"${WRAPPER_FILE}\"
 BINARY_DIR_INCLUDE_GENERATED = \"${BINARY_DIR_INCLUDE_GENERATED}\"
+DT_AUGMENTS = \"${DT_AUGMENTS}\"
 
 [patch.crates-io]
 ${config_paths}
@@ -152,6 +156,7 @@ ${config_paths}
       INCLUDE_DIRS="${include_dirs}"
       INCLUDE_DEFINES="${include_defines}"
       WRAPPER_FILE="${WRAPPER_FILE}"
+      DT_AUGMENTS="${DT_AUGMENTS}"
       BINARY_DIR_INCLUDE_GENERATED="${BINARY_DIR_INCLUDE_GENERATED}"
       cargo build
       # TODO: release flag if release build

dt-rust.yaml

@@ -0,0 +1,86 @@
+# Description of how to augment the devicetree for Rust.
+#
+# Each entry describes an augmentation that will be added to matching nodes in the device tree.
+# The full syntax is described (indirectly) in `zephyr-build/src/devicetree/config.rs`.
+
+# Gpio controllers match for every node that has a `gpio-controller` property.  This is one of the
+# few instances were we can actually just match on a property.
+- name: gpio-controller
+  rules:
+  - type: has_prop
+    value: gpio-controller
+  actions:
+  - type: instance
+    value:
+      raw:
+        type: myself
+      device: crate::sys::gpio::Gpio
+
+# The gpio-leds node will have #children nodes describing each led.  We'll match on the parent
+# having this compatible property.  The nodes themselves are built out of the properties associated
+# with each gpio.
+- name: gpio-leds
+  rules:
+  - type: compatible
+    value:
+      names:
+      - gpio-leds
+      level: 1
+  actions:
+  - type: instance
+    value:
+      raw:
+        type: phandle
+        value: gpios
+      device: crate::sys::gpio::GpioPin
+
+# Flash controllers don't have any particular property to identify them, so we need a list of
+# compatible values that should match.
+- name: flash-controller
+  rules:
+  - type: compatible
+    value:
+      names:
+      - "nordic,nrf52-flash-controller"
+      - "raspberrypi,pico-flash-controller"
+      level: 0
+  actions:
+  - type: instance
+    value:
+      raw:
+        type: myself
+      device: crate::sys::flash::FlashController
+
+# Flash partitions exist as children of a node compatible with "soc-nv-flash" that itself is a child
+# of the controller itself.
+# TODO: Get the write and erase property from the DT if present.
+- name: flash-partition
+  rules:
+  - type: compatible
+    value:
+      names:
+      - "fixed-partitions"
+      level: 1
+  - type: compatible
+    value:
+      names:
+      - "soc-nv-flash"
+      level: 2
+  actions:
+  - type: instance
+    value:
+      raw:
+        type: parent
+        value:
+          level: 3
+          args:
+          - type: reg
+      device: "crate::sys::flash::FlashPartition"
+
+# Generate a pseudo node that matches all of the labels across the tree with their nodes.
+- name: labels
+  rules:
+    - type: root
+  actions:
+  - type: labels
+

zephyr-build/Cargo.toml

@@ -19,3 +19,6 @@ pest = "2.6"
 pest_derive = "2.6"
 quote = "1.0"
 proc-macro2 = "1.0.86"
+serde = { version = "1.0", features = ["derive"] }
+serde_yaml_ng = "0.10"
+anyhow = "1.0.89"

zephyr-build/src/devicetree.rs

@@ -24,10 +24,13 @@ use ordmap::OrdMap;
 use std::{cell::RefCell, collections::BTreeMap, path::Path, rc::Rc};
 
 mod augment;
+pub mod config;
 mod ordmap;
 mod output;
 mod parse;
 
+pub use augment::Augment;
+
 pub struct DeviceTree {
     /// The root of the tree.
     root: Rc<Node>,