examples: add nezha-d1 example package

Signed-off-by: Zhouqi Jiang <[email protected]>

Cargo.toml

@@ -33,4 +33,8 @@ default = ["d1"]
 d1 = []
 
 [workspace]
-members = ["allwinner-rt", "allwinner-rt/macros"]
+members = [
+    "allwinner-rt",
+    "allwinner-rt/macros",
+    "examples/nezha-d1",
+]

allwinner-rt/src/lib.rs

@@ -76,27 +76,27 @@ unsafe extern "C" fn start() -> ! {
         // Clear `.bss` section
         "la     t1, sbss
         la      t2, ebss
-    1:  bgeu    t1, t2, 1f
+    3:  bgeu    t1, t2, 3f
         sd      zero, 0(t1)
         addi    t1, t1, 8
-        j       1b
-    1:  ",
+        j       3b
+    3:  ",
         // Prepare data segment
     "   la      t3, sidata
         la      t4, sdata
         la      t5, edata
-    1:  bgeu    t4, t5, 2f
+    3:  bgeu    t4, t5, 2f
         ld      t6, 0(t3)
         sd      t6, 0(t4)
         addi    t3, t3, 8
         addi    t4, t4, 8
-        j       1b",
+        j       3b",
     "2: ",
         // Start Rust main function
         "call   {main}",
         // Platform halt if main function returns
-    "1: wfi
-        j       1b",
+    "3: wfi
+        j       3b",
         stack      =   sym STACK,
         stack_size = const STACK_SIZE,
         main       =   sym main,

examples/nezha-d1/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "nezha-d1-example"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+allwinner-hal = { path = "../.." }
+allwinner-rt = { path = "../../allwinner-rt" }
+panic-halt = "0.2.0"
+embedded-io = "0.6.1"

examples/nezha-d1/build.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("cargo:rustc-link-arg=-Tallwinner-rt.ld");
+}

examples/nezha-d1/src/bin/uart.rs

@@ -0,0 +1,37 @@
+#![no_std]
+#![no_main]
+
+use allwinner_hal::uart::{Config, Serial};
+use allwinner_rt::{entry, Clocks, Peripherals};
+use embedded_io::{Read, Write};
+use panic_halt as _;
+
+#[entry]
+fn main(p: Peripherals, c: Clocks) {
+    let tx = p.gpio.pb8.into_function::<7>();
+    let rx = p.gpio.pb9.into_function::<7>();
+    let mut serial = Serial::new(p.uart0, (tx, rx), Config::default(), &c, &p.ccu);
+
+    writeln!(serial, "Hello World!").ok();
+
+    let mut buf = [0u8; 64];
+    let mut cur = 0;
+
+    writeln!(serial, "Please input your name (maximum 64 bytes):").unwrap();
+    write!(serial, "> ").unwrap();
+    loop {
+        let mut ch = 0u8;
+        let _len = serial.read(core::slice::from_mut(&mut ch)).unwrap();
+        if ch == b'\r' || ch == b'\n' {
+            break;
+        }
+        buf[cur] = ch;
+        cur += 1;
+        if cur > buf.len() {
+            break;
+        }
+    }
+
+    let name = core::str::from_utf8(&buf).unwrap();
+    writeln!(serial, "Hello, {}!", name).unwrap();
+}

examples/nezha-d1/src/lib.rs

@@ -0,0 +1 @@
+#![no_std]