Using write() for output for better portability

bsp_linux/main.c

@@ -2,10 +2,12 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+#include <unistd.h>
+
 void mission(void);
 
 void done() {
-  printf("done.");
+  printf("done.\n");
   exit(0);
 }
 
@@ -15,11 +17,10 @@ void rust_eh_personality() {
     puts("eh_personality");
 }
 
-void outbyte(uint8_t byte){
-    printf("%c", byte);
-}
-
 int main(void) {
+    printf("std %i sterr %i\n", stdout, stderr);
+    const char * buffer ="123";
+    write(STDOUT_FILENO, buffer, 3);
     mission();
     return 0;
 }

bsp_z7/CMakeLists.txt

@@ -1,4 +1,5 @@
 add_subdirectory(freeRTOS)
 add_subdirectory(ps7_cortexa9_0)
+add_subdirectory(newlib)
 
 target_sources(${TARGET_NAME} PRIVATE main.c)

bsp_z7/newlib/CMakeLists.txt

@@ -0,0 +1 @@
+target_sources(${TARGET_NAME} PRIVATE write.c)

bsp_z7/newlib/write.c

@@ -0,0 +1,15 @@
+#include "xil_printf.h"
+#include "xparameters.h"
+
+int write(int file, char *ptr, int len) {
+  if (ptr == NULL) {
+    return 0;
+  }
+  // TODO file descriptors
+  int todo;
+
+  for (todo = 0; todo < len; todo++) {
+    outbyte(*ptr++);
+  }
+  return len;
+}

bsp_z7/ps7_cortexa9_0/libsrc/standalone/CMakeLists.txt

@@ -22,7 +22,7 @@ target_sources(${TARGET_NAME} PUBLIC
     src/xil_testio.c
     src/xplatform_info.c
     src/getpid.c
-    src/write.c
+    #src/write.c
     src/xil_mem.c
     src/kill.c
     src/xil_mmu.c

mission_rust/src/fsrc/sif.rs

@@ -1,37 +1,76 @@
 // TODO this is platform specific
 
-pub struct Outbytes {}
+pub struct Stdout {}
+pub struct Stderr {}
 
 use core::fmt::{Error, Write};
 
-impl Write for Outbytes {
+extern "C" {
+    pub fn write(fd: core::ffi::c_int, buffer: *const core::ffi::c_void, count: usize) -> core::ffi::c_int;
+}
+
+impl Write for Stdout {
     fn write_str(&mut self, s: &str) -> Result<(), Error> {
-        for c in s.as_bytes() {
+        
-            unsafe {
+        // Safe because write will only read the pointer an then return
-                crate::fsrc::osal::outbyte(*c);
+        let result = unsafe {
-            }
+             write(
-        }
+                1,
+                s.as_bytes().as_ptr() as *const core::ffi::c_void,
+                s.as_bytes().len(),
+            )
+        };
+        // We do not retry incomplete writes, this is stdout after all...
+        let safe_count: i32 = match s.as_bytes().len().try_into() {
+            Ok(count)=> count,
+            Err(_) => return Err(Error) 
+        };
+        if result < safe_count {
+            Err(Error)
+        } else {
             Ok(())
         }
     }
+}
+
+impl Write for Stderr {
+    fn write_str(&mut self, s: &str) -> Result<(), Error> {
+        
+        // Safe because write will only read the pointer an then return
+        let result = unsafe {
+             write(
+                2,
+                s.as_bytes().as_ptr() as *const core::ffi::c_void,
+                s.as_bytes().len(),
+            )
+        };
+        // We do not retry incomplete writes, this is stdout after all...
+        let safe_count: i32 = match s.as_bytes().len().try_into() {
+            Ok(count)=> count,
+            Err(_) => return Err(Error) 
+        };
+        if result < safe_count {
+            Err(Error)
+        } else {
+            Ok(())
+        }
+    }
+}
 
 #[macro_export]
 macro_rules! sifln {
     ($(,)?) => (
-        let mut stdout = Outbytes {};
+        //let mut stdout = Outbytes {};
-        writeln!(stdout);
+        writeln!(Stdout {});
     );
     ($($arg:tt)*) => (
-        let mut stdout = crate::fsrc::sif::Outbytes {};
+        let _alwaysok = writeln!(crate::fsrc::sif::Stdout {}, $($arg)*);
-        let _alwaysok = writeln!(stdout, $($arg)*);
     );
 }
 
 #[macro_export]
 macro_rules! sif {
     ($($arg:tt)*) => (
-        let mut stdout = crate::fsrc::sif::Outbytes {};
+        let _alwaysok = write!(crate::fsrc::sif::Stdout {}, $($arg)*);
-        let _alwaysok = write!(stdout, $($arg)*);
     );
 }
-

mission_rust/src/lib.rs

@@ -21,8 +21,8 @@ fn panic(panic: &PanicInfo<'_>) -> ! {
         osal::stop_it();
     }
     // TODO: Make this unicode-safe 
-    sifln!("");
+    _ = writeln!(crate::fsrc::sif::Stderr {},"");
-    sif!("in task \"");
+    _ = write!(crate::fsrc::sif::Stderr {},"in task \"");
     unsafe {
         //osal::get_task_name is implemented safely in C, so we trust it
         let task_name = core::ffi::CStr::from_ptr(osal::get_task_name());
@@ -32,12 +32,12 @@ fn panic(panic: &PanicInfo<'_>) -> ! {
                 sif!("{}", string);
             }
             Err(_) => {
-                sif!("Schei<EFBFBD> Encoding");
+                _ = writeln!(crate::fsrc::sif::Stderr {},"Schei<EFBFBD> Encoding");
             }
         }
     }
-    sifln!("\":");
+    _ = writeln!(crate::fsrc::sif::Stderr {},"\":");
-    sifln!("{}", panic);
+    _ = writeln!(crate::fsrc::sif::Stderr {},"{}", panic);
     //TODO: stop RTOS, exit if hosted
     unsafe { done() };
     loop {}
@@ -59,7 +59,7 @@ extern "C" fn rust_assert_called(ptr: *const core::ffi::c_char, line: core::ffi:
         }
     };
 
-    panic!("assertion failed at {file_name}:{}", line);
+    panic!("assertion failed at {file_name}:{line}");
 }
 
 #[no_mangle]