Implemented kb shortcuts

kernel/include/kernel/kb.h

@@ -6,6 +6,7 @@
 /*
  * kb_init:
  *  Initializes the keyboard module and registers the IRQ.
+ *  It alsor registers some keyboard shortcuts.
  *
  *  Currently this drive only supports PS2 keyboards with
  *  scan code set 1.
@@ -14,35 +15,4 @@
 
 void kb_init(void);
 
-/*
- * kb_shortcut_struct:
- *  Data type used to register a keyboard shortcut.
- *
- */
-
-struct kb_shortcut_struct {
-
-    uint8_t scancode;
-    uint8_t keystate;
-    void (*handler) (void *);
-    void *arg;
-
-};
-
-typedef struct kb_shortcut_struct kb_shortcut_t;
-
-/*
- * register_shortcut:
- *  Registers a keyboard shortcut.
- *
- * @param scancode - Scancode for shortcut
- * @param keystate - Keystate for shortcut
- * @param handler  - Handler routine for shortcut
- * @param arg      - Argument for handler
- *
- */
-
-int register_shortcut(uint8_t scancode, uint8_t keystate,
-        void (*handler) (void *), void *arg);
-
 #endif

kernel/kb/include/kb_codes.h

@@ -17,5 +17,6 @@
 #define SCANCODE_RSHIFT 0X36
 #define SCANCODE_ALT 0X38
 #define SCANCODE_CAPS 0x3A
+#define SCANCODE_BACKSPACE 0x0E
 
 #endif

kernel/kb/include/kb_internals.h

@@ -4,6 +4,7 @@
 #include "kernel/kb.h"
 #include "kb_tables.h"
 #include "kb_codes.h"
+#include "kb_shortcut.h"
 
 #include <stdint.h>
 #include <stddef.h>
@@ -19,10 +20,14 @@
 uint8_t keycode[KEYCODE_TABLE_SIZE];
 uint8_t keyshift[KEYCODE_TABLE_SIZE];
 
-/* TO BE IMPLEMENTED */
+/*
+ * kb_shortcut - Table containing shortcuts
+ * kb_shortcut_ptr - Index pointer to an available entry
+ *
+ */
 
-__attribute__ ((unused)) kb_shortcut_t kb_shortcut[SHORTCUT_TABLE_SIZE];
-__attribute__ ((unused)) size_t kb_shortcut_ptr;
+kb_shortcut_t kb_shortcut[SHORTCUT_TABLE_SIZE];
+size_t kb_shortcut_ptr;
 
 /*
  * keystate:
@@ -93,7 +98,11 @@ static inline int _is_pressed(uint8_t keystate) {
  *
  */
 
-static inline int _is_backspace(uint8_t scancode) { return scancode == 0x0E; }
+static inline int _is_backspace(uint8_t scancode) {
+
+    return scancode == SCANCODE_BACKSPACE;
+
+}
 
 /*
  * _is_sequence_released:
@@ -107,8 +116,9 @@ static inline int _is_backspace(uint8_t scancode) { return scancode == 0x0E; }
 static inline int _is_sequence_released(uint8_t scancode,
         uint8_t prev_scancode) {
     
-    return ((scancode & 0x80) && !(prev_scancode & 0x80) &&
-            ((scancode & 0x7F) == prev_scancode));
+    return
+        ((scancode & SCANCODE_RELEASED) && !(prev_scancode & SCANCODE_RELEASED)
+        && ((scancode & ~SCANCODE_RELEASED) == prev_scancode));
 
 }
 

kernel/kb/include/kb_shortcut.h

@@ -0,0 +1,56 @@
+#ifndef KB_SHORTCUT_H_
+#define KB_SHORTCUT_H_
+
+/* Typedef for shortcut handler routine. */
+
+typedef void (* shortcut_handler_t) (void *);
+
+/*
+ * kb_shortcut_struct:
+ *  Data type used to register a keyboard shortcut.
+ *
+ */
+
+struct kb_shortcut_struct {
+
+    uint8_t scancode;
+    uint8_t keystate;
+    shortcut_handler_t handler;
+    void *arg;
+
+};
+
+typedef struct kb_shortcut_struct kb_shortcut_t;
+
+/*
+ * _register_shortcut:
+ *  Registers a keyboard shortcut.
+ *
+ * @param scancode - Scancode for shortcut
+ * @param keystate - Keystate for shortcut
+ * @param handler  - Handler routine for shortcut
+ * @param arg      - Argument for handler
+ *
+ * @return         - 0 if successful
+ *                   1 else
+ *
+ */
+
+int _register_shortcut(uint8_t scancode, uint8_t keystate,
+        shortcut_handler_t handler, void *arg);
+
+/*
+ * _execute_shortcut:
+ *  Finds and executes a shortcut.
+ *
+ * @param scancode - Scancode for shortcut
+ * @param keystate - Keystate for shortcut
+ *
+ * @return         - 0 if successful
+ *                   1 else
+ *
+ */
+
+int _execute_shortcut(uint8_t scancode, uint8_t keystate);
+
+#endif

kernel/kb/src/kb.c

@@ -1,7 +1,9 @@
 #include "kernel/kb.h"
 #include "kernel/screen.h"
+#include "kernel/log.h"
 
 #include "kb_internals.h"
+#include "kb_shortcut.h"
 
 #include "i386/context.h"
 #include "i386/irq.h"
@@ -9,7 +11,6 @@
 #include "lib/memio.h"
 
 #include <stddef.h>
-#include <stdio.h>
 
 /*
  * kb_intrpt_handler:
@@ -19,6 +20,10 @@
  *  update the keystate and convert a current scancode if its corresponding
  *  key has not yet been released.
  *
+ *  Aftter the _is_sequence_released check, the routine checks if there is
+ *  and shortcut associated with the current scancode and keystate, if so
+ *  it executes it and returns.
+ *
  *  It also supports special characters, ex: backspace.
  *
  */
@@ -37,6 +42,9 @@ void kb_intrpt_handler(__attribute__ ((unused)) context_t context) {
 
     }
 
+    if (!_execute_shortcut(scancode, keystate))
+        return;
+
     uint8_t asciicode = _to_ascii(scancode);
 
     if (_is_backspace(scancode))
@@ -54,6 +62,7 @@ void kb_intrpt_handler(__attribute__ ((unused)) context_t context) {
  * --------
  *
  *  Fill the translation tables and register the keyboard interrupt.
+ *  Register shortcuts.
  *
  *  keycode and keyshift will be filled with the default value 0xFF. Later,
  *  keycode will be filled with the corresponding ascii codes for each
@@ -148,6 +157,9 @@ void kb_init(void) {
     keyshift['.'] = '>';
     keyshift['/'] = '?';
 
+    _register_shortcut(SCANCODE_BACKSPACE, KEYSTATE_CTRL_PRESSED,
+            reg_dump, (void *) 0);
+
     register_irq(IRQ1, kb_intrpt_handler);
 
 }

kernel/kb/src/kb_shortcut.c

@@ -0,0 +1,73 @@
+#include "kb_internals.h"
+
+#include "kb_codes.h"
+
+/*
+ * _register_shortcut:
+ * -------------------
+ *
+ *  Make sure that PRESSED bit is set in keystate. If there is already a
+ *  handler for the same scancode and keystate, update its handler routine
+ *  and its handler routine argument.
+ *
+ *  Otherwise put the handler on the next free position. THe routine returns
+ *  a positive number if an error occurs.
+ *
+ */
+
+int _register_shortcut(uint8_t scancode, uint8_t keystate,
+        void (*handler) (void *), void *arg) {
+
+    keystate |= KEYSTATE_PRESSED;
+
+    size_t i = 0;
+    for ( ; i < kb_shortcut_ptr; i++)
+        if (kb_shortcut[i].scancode == scancode &&
+                kb_shortcut[i].keystate == keystate)
+            break;
+
+    if (i < kb_shortcut_ptr) {
+
+        kb_shortcut[i].handler = handler;
+        kb_shortcut[i].arg = arg;
+        return 0;
+
+    }
+
+    if (kb_shortcut_ptr == SHORTCUT_TABLE_SIZE)
+        // TODO: a robust error handler
+        return 1;
+
+    kb_shortcut[kb_shortcut_ptr] =
+        (kb_shortcut_t) {scancode, keystate, handler, arg};
+
+    kb_shortcut_ptr++;
+
+    return 0;
+
+}
+
+/*
+ * _execute_shortcut:
+ * ------------------
+ *
+ *  Find the corresponding handler for scancode and keystate and execute it.
+ *
+ */
+
+int _execute_shortcut(uint8_t scancode, uint8_t keystate) {
+
+    size_t i = 0;
+    for ( ; i < kb_shortcut_ptr; i++)
+        if (kb_shortcut[i].scancode == scancode &&
+                kb_shortcut[i].keystate == keystate)
+            break;
+
+    if (i < kb_shortcut_ptr && kb_shortcut[i].handler) {
+        kb_shortcut[i].handler(kb_shortcut[i].arg);
+        return 0;
+    }
+
+    return 1;
+
+}