Changeset 407 for trunk/kernel/devices/dev_txt.h

Timestamp:

Nov 7, 2017, 3:08:12 PM (6 years ago)

Author:

alain

Message:

First implementation of fork/exec.

File:

• trunk/kernel/devices/dev_txt.h (modified) (5 diffs)

trunk/kernel/devices/dev_txt.h

@@ -36 +36 @@
  *
  * This multi-channels generic TXT device provides access to a text terminal.
- * It supports three operation types :
+ *
+ * It supports two operations that must be implemented by the driver cmd() function:
  * - TXT_READ : read a single character from the text terminal identified by its channel
  *   index, using a descheduling strategy for the calling thread.
  * - TXT_WRITE : write a character string to the text terminal identified by its channel
  *   index, using a descheduling strategy for the calling thread.
- * - TXT_SYNC_WRITE : write a character string to the terminal identified by its channel
- *   index, using a busy waiting strategy for the calling thread.
+ *
+ * It supports one operation, that must be implemented by the driver aux() function  
+ * - TXT_SYNC_WRITE write a character string to the TXT0 kernel terminal, using a busy 
+ *   waiting strategy for the calling thread. 
  *****************************************************************************************/
 
@@ -58 +61 @@
 
 /******************************************************************************************
- * This defines the (implementation independent) command passed to the driver.
+ * This defines the arguments passed to the driver CMD function.
  *****************************************************************************************/
 
@@ -65 +68 @@
     TXT_READ       = 0,
     TXT_WRITE      = 1,
-    TXT_SYNC_WRITE = 2,
 };
 
@@ -77 +79 @@
 }
 txt_command_t;
+
+/******************************************************************************************
+ * This defines the arguments passed to the driver AUX function.
+ * This function implement the TXT_SYNC_WRITE operation.
+ *****************************************************************************************/
+
+typedef struct txt_aux_s
+{
+    xptr_t      dev_xp;    /*! extended pointer on the TXT0 device descriptor            */
+    char      * buffer;    /*! local pointer on characters array                         */
+    uint32_t    count;     /*! number of characters in buffer                            */
+}
+txt_aux_t;
 
 /******************************************************************************************
@@ -122 +137 @@
 
 /***************************************************************************************
- * This low-level blocking function is used by the kernel to display one string on a
- * given TXT channel without descheduling the calling thread, without registering it
- * in the TXT device waiting queue, and without using the TXT irq.
+ * This blocking function is used by the kernel to display a string on the TXT0
+ * terminal, without descheduling the calling thread, without registering it
+ * in the TXT0 device waiting queue, without using the TXT0 irq, and without
+ * interfering with another possible TXT access to another terminal.
+ * As it is used for debug, the command arguments <buffer> and <count> are registerd
+ * in a specific "dbg_cmd" field of the calling thread.
+ * other TXT accesses. 
  ****************************************************************************************
- * @ channel   : TXT channel index.
  * @ buffer    : local pointer on source buffer containing the string.
  * @ count     : number of characters.
  * @ returns 0 if success / returns EINVAL if error.
  ***************************************************************************************/
-error_t dev_txt_sync_write( uint32_t   channel,
-                            char     * buffer,
+error_t dev_txt_sync_write( char     * buffer,
                             uint32_t   count );