Gpio7

examples/hello_rust/hello_rust_main.rs

@@ -37,14 +37,25 @@ use core::panic::PanicInfo;
 
 extern "C" {
     pub fn printf(format: *const u8, ...) -> i32;
+    pub fn open(path: *const u8, oflag: i32, ...) -> i32;
+    pub fn close(fd: i32) -> i32;
+    pub fn ioctl(fd: i32, request: i32, ...) -> i32;
+    pub fn usleep(usec: u32) -> u32;
 }
 
 /****************************************************************************
- * Private functions
+ * Constants
+ ****************************************************************************/
+
+pub const O_WRONLY: i32 = 1 << 1;
+pub const ULEDIOC_SETALL: i32 = 0x1d03;
+
+/****************************************************************************
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Panic handler (needed for [no_std] compilation)
+ * Panic Handler (needed for [no_std] compilation)
  ****************************************************************************/
 
 #[panic_handler]
@@ -53,7 +64,7 @@ fn panic(_panic: &PanicInfo<'_>) -> ! {
 }
 
 /****************************************************************************
- * Public functions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
@@ -62,13 +73,43 @@ fn panic(_panic: &PanicInfo<'_>) -> ! {
 
 #[no_mangle]
 pub extern "C" fn hello_rust_main(_argc: i32, _argv: *const *const u8) -> i32 {
-    /* "Hello, Rust!!" using printf() from libc */
-
     unsafe {
+        /* "Hello, Rust!!" using printf() from libc */
+
         printf(b"Hello, Rust!!\n\0" as *const u8);
+
+        /* Blink LED 1 using ioctl() from NuttX */
+
+        printf(b"Opening /dev/userleds\n\0" as *const u8);
+        let fd = open(b"/dev/userleds\0" as *const u8, O_WRONLY);
+        if fd < 0 {
+            printf(b"Unable to open /dev/userleds, skipping the blinking\n\0" as *const u8);
+            return 1;
+        }
+
+        printf(b"Set LED 1 to 1\n\0" as *const u8);
+        let ret = ioctl(fd, ULEDIOC_SETALL, 1);
+        if ret < 0 {
+            printf(b"ERROR: ioctl(ULEDIOC_SETALL) failed\n\0" as *const u8);
+            close(fd);
+            return 1;
+        }
+
+        printf(b"Sleeping...\n\0" as *const u8);
+        usleep(500_000);
+
+        printf(b"Set LED 1 to 0\n\0" as *const u8);
+        let ret = ioctl(fd, ULEDIOC_SETALL, 0);
+        if ret < 0 {
+            printf(b"ERROR: ioctl(ULEDIOC_SETALL) failed\n\0" as *const u8);
+            close(fd);
+            return 1;
+        }
+
+        close(fd);
     }
 
-    /* exit with status 0 */
+    /* Exit with status 0 */
 
     0
 }