From bb89adb6fd7354abfe1d531be97ab2f5947fc5da Mon Sep 17 00:00:00 2001
From: David Brown <david.brown@linaro.org>
Date: Tue, 15 Oct 2024 09:30:15 -0600
Subject: [PATCH] zephyr: docgen

Add a small docgen crate.  To help facilitate checking the docs, this
project can be built, and then `cargo doc` run there.  This includes the
symlink for the config file, because that is needed in order for this to
be able to build.

Signed-off-by: David Brown <david.brown@linaro.org>
---
 docgen/.cargo/config.toml |  1 +
 docgen/.gitignore         |  7 +++++++
 docgen/CMakeLists.txt     |  8 ++++++++
 docgen/Cargo.toml         | 16 ++++++++++++++++
 docgen/prj.conf           |  5 +++++
 docgen/src/lib.rs         | 16 ++++++++++++++++
 6 files changed, 53 insertions(+)
 create mode 120000 docgen/.cargo/config.toml
 create mode 100644 docgen/.gitignore
 create mode 100644 docgen/CMakeLists.txt
 create mode 100644 docgen/Cargo.toml
 create mode 100644 docgen/prj.conf
 create mode 100644 docgen/src/lib.rs

diff --git a/docgen/.cargo/config.toml b/docgen/.cargo/config.toml
new file mode 120000
index 00000000..f26aaf03
--- /dev/null
+++ b/docgen/.cargo/config.toml
@@ -0,0 +1 @@
+../../../../../zephyr/build/rust/sample-cargo-config.toml
\ No newline at end of file
diff --git a/docgen/.gitignore b/docgen/.gitignore
new file mode 100644
index 00000000..80e243ad
--- /dev/null
+++ b/docgen/.gitignore
@@ -0,0 +1,7 @@
+# In this case, we do want the symlink checked in.  We'll assume we have the module in the standard
+# module place.
+#
+# On Windows, this symlink will just get checked out as a regular file and will have to be replaced
+# with a copy (or real symlinks enabled).  But, this shouldn't affect CI runs of the documentation,
+# which are done on Linux.
+!.cargo/
diff --git a/docgen/CMakeLists.txt b/docgen/CMakeLists.txt
new file mode 100644
index 00000000..3030520d
--- /dev/null
+++ b/docgen/CMakeLists.txt
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+
+project(hello_rust_world)
+rust_cargo_application()
diff --git a/docgen/Cargo.toml b/docgen/Cargo.toml
new file mode 100644
index 00000000..5588550d
--- /dev/null
+++ b/docgen/Cargo.toml
@@ -0,0 +1,16 @@
+# Copyright (c) 2024 Linaro LTD
+# SPDX-License-Identifier: Apache-2.0
+
+[package]
+# This must be rustapp for now.
+name = "rustapp"
+version = "3.7.0"
+edition = "2021"
+description = "A small application to generate documentation"
+license = "Apache-2.0 or MIT"
+
+[lib]
+crate-type = ["staticlib"]
+
+[dependencies]
+zephyr = "3.7.0"
diff --git a/docgen/prj.conf b/docgen/prj.conf
new file mode 100644
index 00000000..930445c6
--- /dev/null
+++ b/docgen/prj.conf
@@ -0,0 +1,5 @@
+# Copyright (c) 2024 Linaro LTD
+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_RUST=y
+CONFIG_RUST_ALLOC=y
diff --git a/docgen/src/lib.rs b/docgen/src/lib.rs
new file mode 100644
index 00000000..b29be52b
--- /dev/null
+++ b/docgen/src/lib.rs
@@ -0,0 +1,16 @@
+// Copyright (c) 2024 Linaro LTD
+// SPDX-License-Identifier: Apache-2.0
+
+#![no_std]
+
+use zephyr::printkln;
+
+// Reference the Zephyr crate so that the panic handler gets used.  This is only needed if no
+// symbols from the crate are directly used.
+extern crate zephyr;
+
+#[no_mangle]
+extern "C" fn rust_main() {
+    printkln!("Hello world from Rust on {}",
+              zephyr::kconfig::CONFIG_BOARD);
+}