feat(demo): add esp32-no-std demo example (#158)

Author: orhun

.github/workflows/ci.yml

@@ -18,7 +18,6 @@ env:
   GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
 jobs:
-
   typos:
     name: Check for typos
     runs-on: ubuntu-latest
@@ -33,8 +32,8 @@ jobs:
       - uses: actions/checkout@v6
       - uses: DavidAnson/markdownlint-cli2-action@v22
         with:
-          globs: '**/*.md,#CHANGELOG.md'
-          separator: ','
+          globs: "**/*.md,#CHANGELOG.md"
+          separator: ","
 
   fmt:
     name: Run fmt
@@ -70,6 +69,11 @@ jobs:
             dir: examples/esp32-std-demo
             target: xtensa-esp32-espidf
             setup_xtensa: true
+          # no-std demo
+          - name: esp32-no-std-demo
+            dir: examples/esp32-no-std-demo
+            target: ""
+            setup_xtensa: true
           # EPD Waveshare demo
           - name: epd-waveshare-demo
             dir: examples/epd-waveshare-demo

Cargo.lock

@@ -0,0 +1,12 @@
+[target.xtensa-esp32-none-elf]
+runner = "espflash flash --monitor --chip esp32"
+
+[env]
+ESP_LOG = "trace"
+
+[build]
+target = "xtensa-esp32-none-elf"
+rustflags = ["-C", "link-arg=-nostartfiles"]
+
+[unstable]
+build-std = ["alloc", "core"]

examples/esp32-no-std-demo/.cargo/config.toml

@@ -0,0 +1 @@
+stack-size-threshold = 8192

examples/esp32-no-std-demo/.clippy.toml

@@ -0,0 +1,34 @@
+[package]
+name = "esp32-no-std-demo"
+version = "0.1.0"
+edition = "2024"
+publish = false
+
+[[bin]]
+name = "esp32-no-std-demo"
+harness = false # do not use the built in cargo test harness -> resolve rust-analyzer errors
+
+# Commented out due to workspace profiles being used
+# Feel free to uncomment and adjust if you have copied this outside of a workspace
+#
+# [profile.release]
+# opt-level = 3
+#
+# [profile.dev]
+# Symbols are nice and they don't increase the size on Flash
+# debug = true
+# opt-level = 3
+
+[dependencies]
+esp-hal = { version = "~1.0", features = ["esp32", "log-04", "unstable"] }
+esp-bootloader-esp-idf = { version = "0.4.0", features = ["esp32", "log-04"] }
+esp-alloc = "0.9.0"
+esp-println = { version = "0.16.1", features = ["esp32", "log-04"] }
+embedded-hal-bus = "0.3.0"
+mipidsi = "0.9.0"
+critical-section = "1.2.0"
+mousefood = { path = "../../mousefood/" }
+ratatui = { workspace = true, default-features = false, features = ["all-widgets"] }
+log = "0.4.27"
+time = { version = "0.3.45", default-features = false }
+libm = "0.2.16"

examples/esp32-no-std-demo/Cargo.toml

@@ -0,0 +1,70 @@
+fn main() {
+    linker_be_nice();
+    // make sure linkall.x is the last linker script (otherwise might cause problems with flip-link)
+    println!("cargo:rustc-link-arg=-Tlinkall.x");
+}
+
+fn linker_be_nice() {
+    let args: Vec<String> = std::env::args().collect();
+    if args.len() > 1 {
+        let kind = &args[1];
+        let what = &args[2];
+
+        match kind.as_str() {
+            "undefined-symbol" => match what.as_str() {
+                what if what.starts_with("_defmt_") => {
+                    eprintln!();
+                    eprintln!(
+                        "💡 `defmt` not found - make sure `defmt.x` is added as a linker script and you have included `use defmt_rtt as _;`"
+                    );
+                    eprintln!();
+                }
+                "_stack_start" => {
+                    eprintln!();
+                    eprintln!("💡 Is the linker script `linkall.x` missing?");
+                    eprintln!();
+                }
+                what if what.starts_with("esp_rtos_") => {
+                    eprintln!();
+                    eprintln!(
+                        "💡 `esp-radio` has no scheduler enabled. Make sure you have initialized `esp-rtos` or provided an external scheduler."
+                    );
+                    eprintln!();
+                }
+                "embedded_test_linker_file_not_added_to_rustflags" => {
+                    eprintln!();
+                    eprintln!(
+                        "💡 `embedded-test` not found - make sure `embedded-test.x` is added as a linker script for tests"
+                    );
+                    eprintln!();
+                }
+                "free"
+                | "malloc"
+                | "calloc"
+                | "get_free_internal_heap_size"
+                | "malloc_internal"
+                | "realloc_internal"
+                | "calloc_internal"
+                | "free_internal" => {
+                    eprintln!();
+                    eprintln!(
+                        "💡 Did you forget the `esp-alloc` dependency or didn't enable the `compat` feature on it?"
+                    );
+                    eprintln!();
+                }
+                _ => (),
+            },
+            // we don't have anything helpful for "missing-lib" yet
+            _ => {
+                std::process::exit(1);
+            }
+        }
+
+        std::process::exit(0);
+    }
+
+    println!(
+        "cargo:rustc-link-arg=-Wl,--error-handling-script={}",
+        std::env::current_exe().unwrap().display()
+    );
+}

examples/esp32-no-std-demo/build.rs

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "esp"