From 5040ad1492f37b5c7efc06cc1f558bdad6a600fa Mon Sep 17 00:00:00 2001
From: xengineering <me@xengineering.eu>
Date: Sun, 23 Mar 2025 18:08:44 +0100
Subject: Provide default key path in CMake files

This makes calling cmake for this device repository easier.
---
 CMakeLists.txt |  4 ++++
 README.md      | 11 +++++++----
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a21c5d0..e539037 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,6 +2,10 @@ cmake_minimum_required(VERSION 3.10)
 
 project(iot-contact LANGUAGES NONE)
 
+set(KEY_DEFAULT "$ENV{HOME}/mcuboot/key.pem")
+set(KEY ${KEY_DEFAULT} CACHE STRING "Firmware signing key path")
+message(STATUS "Firmware signing key path: ${KEY}")
+
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake" ${CMAKE_MODULE_PATH})
 
 add_subdirectory(fw)
diff --git a/README.md b/README.md
index 6fd7c0f..8b39597 100644
--- a/README.md
+++ b/README.md
@@ -10,11 +10,11 @@ Currently two boards are supported:
 
 ## Usage
 
-To build the firmware a firmware signing key is required. It is generated with
-the `imgtool.py`.
+To build the device repository a firmware signing key is required. It is
+generated with the `imgtool.py`.
 
 ```
-mkdir -p ~/mcuboot
+mkdir ~/mcuboot
 ./imgtool.py keygen --key ~/mcuboot/key.pem --type ed25519
 ```
 
@@ -26,10 +26,13 @@ The bootloader is built for `nucleo_f767zi` since the simulation board is
 currently not supported.
 
 ```
-cmake -Bbuild -GNinja -DKEY=~/mcuboot/key.pem
+cmake -Bbuild -GNinja
 ninja -C build
 ```
 
+A custom key location can be set by providing `-DKEY=/path/to/key` to the CMake
+call.
+
 To run the simulated firmware a virtual network interface `zeth` and a router
 advertisement daemon have to be provided with an embedded script. Root rights
 are required for that (prefix e.g. with `sudo`).
-- 
cgit v1.2.3-70-g09d2