[iar][syscalls] 补充注释

components/libc/compilers/dlib/syscall_close.c

@@ -11,7 +11,13 @@
 #include <LowLevelIOInterface.h>
 #include <unistd.h>
 
+/*
+ * The "__close" function should close the file corresponding to
+ * "handle".  It should return 0 on success and nonzero on failure.
+ */
+
 #pragma module_name = "?__close"
+
 int __close(int handle)
 {
     if (handle == _LLIO_STDOUT ||

components/libc/compilers/dlib/syscall_lseek.c

@@ -11,7 +11,22 @@
 #include <LowLevelIOInterface.h>
 #include <unistd.h>
 
+/*
+ * The "__lseek" function makes the next file operation (__read or
+ * __write) act on a new location.  The parameter "whence" specifies
+ * how the "offset" parameter should be interpreted according to the
+ * following table:
+ *
+ *  0 (=SEEK_SET) - Goto location "offset".
+ *  1 (=SEEK_CUR) - Go "offset" bytes from the current location.
+ *  2 (=SEEK_END) - Go to "offset" bytes from the end.
+ *
+ * This function should return the current file position, or -1 on
+ * failure.
+ */
+
 #pragma module_name = "?__lseek"
+
 long __lseek(int handle, long offset, int whence)
 {
     if (handle == _LLIO_STDOUT ||

components/libc/compilers/dlib/syscall_open.c

@@ -12,6 +12,11 @@
 #include <LowLevelIOInterface.h>
 #include <fcntl.h>
 
+/*
+ * The "__open" function opens the file named "filename" as specified
+ * by "mode".
+ */
+
 #pragma module_name = "?__open"
 
 int __open(const char *filename, int mode)

components/libc/compilers/dlib/syscall_read.c

@@ -19,7 +19,19 @@
 #define DBG_LVL    DBG_INFO
 #include <rtdbg.h>
 
+/*
+ * The "__read" function reads a number of bytes, at most "size" into
+ * the memory area pointed to by "buffer".  It returns the number of
+ * bytes read, 0 at the end of the file, or _LLIO_ERROR if failure
+ * occurs.
+ *
+ * The template implementation below assumes that the application
+ * provides the function "MyLowLevelGetchar".  It should return a
+ * character value, or -1 on failure.
+ */
+
 #pragma module_name = "?__read"
+
 size_t __read(int handle, unsigned char *buf, size_t len)
 {
 #ifdef RT_USING_POSIX

components/libc/compilers/dlib/syscall_remove.c

@@ -11,12 +11,18 @@
 #include <LowLevelIOInterface.h>
 #include <unistd.h>
 
+/*
+ * The "remove" function should remove the file named "filename".  It
+ * should return 0 on success and nonzero on failure.
+ */
+
 #pragma module_name = "?remove"
-int remove(const char *val)
+
+int remove(const char *filename)
 {
 #ifdef RT_USING_POSIX
-    return unlink(val);
+    return unlink(filename);
 #else
-    return -1;
+    return _LLIO_ERROR;
 #endif /* RT_USING_POSIX */
 }

components/libc/compilers/dlib/syscall_write.c

@@ -19,6 +19,20 @@
 #define DBG_LVL    DBG_INFO
 #include <rtdbg.h>
 
+/*
+ * The "__write" function should output "size" number of bytes from
+ * "buffer" in some application-specific way.  It should return the
+ * number of characters written, or _LLIO_ERROR on failure.
+ *
+ * If "buffer" is zero then __write should perform flushing of
+ * internal buffers, if any.  In this case "handle" can be -1 to
+ * indicate that all handles should be flushed.
+ *
+ * The template implementation below assumes that the application
+ * provides the function "MyLowLevelPutchar".  It should return the
+ * character written, or -1 on failure.
+ */
+
 #pragma module_name = "?__write"
 
 size_t __write(int handle, const unsigned char *buf, size_t len)