Espresso 0.0.1d

drivers/ps2_keyboard.c

@@ -36,15 +36,22 @@ static bool shift_pressed = false;
 /* State for caps-lock key */
 static bool capslock_pressed = false;
 
-volatile char current_char;
+/* Used for arrow keys among others */
+static bool extended = false;
+
+static bool is_new_char = false;
+static bool is_new_key = false;
+
+volatile unsigned char current_char;
 volatile char* current_string = NULL;
 volatile int32_t current_length = 0;
 volatile int32_t capacity = 0;
+volatile uint16_t current_key;
 
 
 static const char scancode_map[128] = {
   0,  27, '1','2','3','4','5','6','7','8','9','0','-','=','\b', /* Backspace */
-  '\t', // Tab
+  '\t', /* Tab */
   'q','w','e','r','t','y','u','i','o','p','[',']','\n', /* Enter */
   0, /* Control */
   'a','s','d','f','g','h','j','k','l',';','\'','`',
@@ -67,7 +74,46 @@ void keyboard_init(void)
 
 char get_char(void)
 {
-  return current_char;
+  /*
+    ASCII code 5 (Enquiry) is/was used in legacy systems meant for requesting a response from a remote terminal or device.
+    For example, one system might send ENQ (ASCII 5), and the receiver could reply with ACK (ASCII 6) to indicate it’s ready or still online.
+    
+    In modern computing, ENQ is largely obsolete:
+
+    - Terminal emulators, shells, operating systems, and network protocols generally do not use ENQ.
+
+    - It's not used in text files, programming, or standard communications.
+
+    - It may still appear in legacy systems, embedded devices, or proprietary serial protocols, but that's niche.
+  */
+  char temp = 5;
+  
+  if (is_new_char)
+  {
+    temp = current_char;
+  }
+  
+  is_new_char = false;
+  
+  return temp;
+}
+
+uint16_t get_key(void)
+{
+  uint16_t temp = 0xFFFA;
+  
+  if (is_new_key)
+  {
+    temp = current_key;
+    is_new_key = false;
+  }
+  else if (is_new_char)
+  {
+    temp = (uint16_t)current_char;
+    is_new_char = false;
+  }
+  
+  return temp;
 }
 
 char* get_string(void)
@@ -118,7 +164,8 @@ static void free_current_string(void)
   }
 }
 
-void keyboard_handler(void) {
+void keyboard_handler(void)
+{
   uint8_t scancode = inb(PS2_DATA_PORT);
 
   /* Handle shift press/release */
@@ -137,41 +184,76 @@ void keyboard_handler(void) {
     capslock_pressed = !capslock_pressed;
     return;
   }
+  else if (scancode == 0xE0)
+  {
+    extended = true;
+    return;
+  }
 
 
   if (scancode & 0x80)
   {
-    /* Key release event, ignore for now */
-  } else
+    extended = false;
+  }
+  else
   {
-    char c = scancode_map[scancode];
-    if ((shift_pressed ^ capslock_pressed) && c >= 'a' && c <= 'z') {
+    uint16_t c = (uint16_t)scancode_map[scancode];
+    if ((shift_pressed ^ capslock_pressed) && ((char)c >= 'a') && ((char)c <= 'z'))
+    {
       c -= 32; /* Convert to uppercase */
     }
     else if (shift_pressed)
     {
-      c = (char) terminal_get_shifted((unsigned char) c);
+      c = (uint16_t) terminal_get_shifted((unsigned char) c);
     }
     
-    if (scancode == 0x1C) {
+    /*if (scancode == 0x1C) {
       printf("\n");
       return;
-    }
+    }*/
 
 
+    if (extended)
+    {
+      switch (scancode)
+      {
+        case 0x48:
+          c = KEY_ARROW_UP;
+          break;
+        case 0x50:
+          c = KEY_ARROW_DOWN;
+          break;
+        case 0x4B:
+          c = KEY_ARROW_LEFT;
+          break;
+        case 0x4D:
+          c = KEY_ARROW_RIGHT;
+          break;
+        default:
+          c = KEY_NONE;
+          break;
+      }
+      
+      current_key = c;
+      
+      is_new_key = true;
+      extended = false;
+      
+      return;
+    }
+
     if (c)
     {
       current_char = c;
       
+      is_new_char = true;
+      
       if (c == '\n')
       {
         free_current_string();
       }
-      else
-      {
-        append_char(c);
-        printf("%c", c);
-      }
+      
+      append_char(c);
     }
   }
 }