move uarte solution to its own folder

down-the-stack/solutions/.cargo/config.toml

@@ -0,0 +1,19 @@
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+# (..)
+rustflags = [
+  "-C", "linker=flip-link", # adds stack overflow protection
+  "-C", "link-arg=-Tdefmt.x", # defmt support
+  # (..)
+]
+
+[target.thumbv7em-none-eabihf]
+# set custom cargo runner to flash & run on embedded target when we call `cargo run`
+# for more information, check out https://github.com/knurling-rs/probe-run
+runner = "probe-run --chip nRF52840_xxAA"
+rustflags = [
+  "-C", "link-arg=-Tlink.x",
+]
+
+[build]
+# cross-compile to this target
+target = "thumbv7em-none-eabihf" # = ARM Cortex-M4

down-the-stack/solutions/Cargo.toml

@@ -0,0 +1,50 @@
+[package]
+authors = ["Tanks Transfeld <tanks.transfeld@ferrous-systems.com>"]
+edition = "2018"
+license = "MIT OR Apache-2.0"
+name = "uarte_enable_solution"
+version = "0.0.0"
+
+[dependencies]
+cortex-m = {version = "0.7.6", features = ["critical-section-single-core"]}
+cortex-m-rt = "0.7.2"
+dk_bsc = { path = "../dk_bsc" }
+dk_pac = { path = "../dk_pac", features = ["critical-section"]}
+heapless = "0.7.16"
+panic-probe = { version = "0.3.0", features = ["print-defmt"] }
+defmt = "0.3.2"
+defmt-rtt = "0.3.2"
+
+# optimize code in both profiles
+[profile.dev]
+codegen-units = 1
+debug = 2
+debug-assertions = true # !
+incremental = false
+lto = "fat"
+opt-level = 'z' # !
+overflow-checks = false
+
+[profile.release]
+codegen-units = 1
+debug = 1
+debug-assertions = false
+incremental = false
+lto = "fat"
+opt-level = 3
+overflow-checks = false
+
+[features]
+
+
+default = [
+  "other-feature"
+]
+other-feature = []
+# do NOT modify these features
+defmt-default = []
+defmt-trace = []
+defmt-debug = []
+defmt-info = []
+defmt-warn = []
+defmt-error = []

down-the-stack/solutions/README.md

@@ -0,0 +1,4 @@
+# Solutions
+
+This program does not build if the pac is not generated!
+The file is only for reference. 

down-the-stack/solutions/src/bin/uarte_enable.rs

@@ -6,7 +6,7 @@ use cortex_m_rt::entry;
 use dk_pac::UARTE0;
 
 // this imports `down-the-stack/apps/lib.rs` to retrieve our global logger + panicking-behavior
-use apps as _;
+use uarte_enable_solution as _;
 use defmt;
 use defmt_rtt as _; // global logger
 

down-the-stack/solutions/src/lib.rs

@@ -0,0 +1,10 @@
+#![no_std]
+
+use panic_probe as _;
+
+// same panicking *behavior* as `panic-probe` but doesn't print a panic message
+// this prevents the panic message being printed *twice* when `defmt::panic` is invoked
+#[defmt::panic_handler]
+fn panic() -> ! {
+    cortex_m::asm::udf()
+}