Changeset 598 for trunk/kernel/fs/devfs.h

Timestamp:

Nov 10, 2018, 3:06:00 PM (5 years ago)

Author:

alain

Message:

1) Modify the devfs_user_move() function to support large user buffer transfer to/from TXT device.
2) Cosmetic: Improve debug.

File:

• trunk/kernel/fs/devfs.h (modified) (2 diffs)

trunk/kernel/fs/devfs.h

@@ -119 +119 @@
                        
 /****************************************************************************************** 
- * This function moves <size> bytes between a device, and a - possibly distributed - 
- * user space <buffer>. It uses the <file_xp> and <to_buffer> arguments, to call the 
- * relevant device access function.
- * It is called by the sys_read() and sys_write() functions.
- * The <size> argument cannot be larger than the CONFIG_TXT_KBUF_SIZE configuration
- * parameter, as this function makes a copy between the user space buffer, and a local
- * kernel buffer allocated in the kernel stack.
+ * This function is called by the sys_read() and sys_write() functions.
+ * It moves <size> bytes between a TXT device, and an user space <u_buf> buffer. 
+ * It uses the <file_xp> and <to_buffer> arguments, to call the relevant device function.
+ * It uses a kernel buffer allocated in the calling thread kernel stack.
+ * If the <size> argument is larger than CONFIG_TXT_KBUF_SIZE, the user buffer is split
+ * in smaller chunks to be copied from the user buffer to this kernel buffer.
  ******************************************************************************************
  * @ to_buffer : device -> buffer if true / buffer -> device if false. 
@@ -135 +134 @@
 int devfs_user_move( bool_t   to_buffer,
                      xptr_t   file_xp, 
-                     void   * u_buf,
+                     char   * u_buf,
                      uint32_t size );