Use "bool" type and true/false whenever appropriate, for better semantics.

src/boot.c

@@ -108,7 +108,7 @@ void boot_animate_keyboard(unsigned long max_ticks, unsigned long ticks, unsigne
  *
  * @return 0 if not bootable, non-zero if bootable
  */
-short is_bootable(unsigned char * sector, short device) {
+bool is_bootable(unsigned char * sector, short device) {
     switch(device) {
         case BDEV_FDC:
             // The SDC and HDC boot off the MBR...
@@ -118,7 +118,7 @@ short is_bootable(unsigned char * sector, short device) {
                 if ((sector[BOOT_SIG_VBR_OFF] == ((BOOT_SIG >> 8) & 0x00FF)) &&
                     (sector[BOOT_SIG_VBR_OFF+1] == (BOOT_SIG & 0x00FF))) {
                     // The CPU is supported, and the boot signature is correct
-                    return 1;
+                    return true;
                 }
             }
             break;
@@ -132,7 +132,7 @@ short is_bootable(unsigned char * sector, short device) {
                 if ((sector[BOOT_SIG_MBR_OFF] == ((BOOT_SIG >> 8) & 0x00FF)) &&
                     (sector[BOOT_SIG_MBR_OFF+1] == (BOOT_SIG & 0x00FF))) {
                     // The CPU is supported, and the boot signature is correct
-                    return 1;
+                    return true;
                 }
             }
             break;
@@ -143,7 +143,7 @@ short is_bootable(unsigned char * sector, short device) {
     }
 
     // If we have reached this point, the sector is not bootable
-    return 0;
+    return false;
 }
 
 /**

src/cli/dos_copy.c

@@ -56,17 +56,17 @@
  * Check to see if the path points to a directory
  *
  * @param path the path to check
- * @return 1 if the path points to a directory, 0 otherwise
+ * @return true if the path points to a directory, false otherwise
  */
-short is_directory(const char * path) {
+bool is_directory(const char * path) {
     t_file_info file;
 
     short result = sys_fsys_stat(path, &file);
     if ((result < 0) || ((file.attributes & FSYS_AM_DIR) == 0)) {
-        return 0;
+        return false;
     }
 
-    return 1;
+    return true;
 }
 
 /**

src/dev/console.c

@@ -94,15 +94,15 @@ const t_ansi_seq ansi_sequence[] = {
  * c = the character to test
  *
  * Returns:
- * 0 if the character is not an ANSI initial, 1 if it is
+ * false if the character is not an ANSI initial, true if it is
  */
-short ansi_start_code(char c) {
+bool ansi_start_code(char c) {
     switch (c) {
         case '\x1b':
-            return 1;
+            return true;
 
         default:
-            return 0;
+            return false;
     }
 }
 
@@ -650,7 +650,7 @@ short con_write(p_channel chan, const uint8_t * buffer, short size) {
     return i;
 }
 
-short con_has_input(p_channel chan) {
+bool con_has_input(p_channel chan) {
     p_console_data con_data;
     char c;
 
@@ -659,7 +659,7 @@ short con_has_input(p_channel chan) {
 
     if (con_data->key_buffer != 0) {
         /* If we already peeked and have a character... return true */
-        return 1;
+        return true;
 
     } else {
         /* Otherwise, peek at the keyboard to see if there is a valid key */
@@ -681,12 +681,12 @@ short con_has_input(p_channel chan) {
 
         if (c == 0) {
             /* No: return false */
-            return 0;
+            return false;
 
         } else {
             /* Yes: save the key we got and return true */
             con_data->key_buffer = c;
-            return 1;
+            return true;
         }
     }
 }

src/dev/fdc.c

@@ -114,16 +114,16 @@ void fdc_media_change() {
  * Check to see if the media has changed
  * If so, recalibrate the drive and flag the change
  */
-short fdc_media_check_change() {
+bool fdc_media_check_change() {
     // Check for the a disk change
     if (*FDC_DIR & 0x80) {
         // The disk has changed... recalibrate and set that it's changed
         fdc_recalibrate();
         fdc_seek(1);
         g_fdc_stat = FDC_STAT_NOINIT;
-        return 1;
+        return true;
     }
-    return 0;
+    return false;
 }
 
 /*

src/dev/fsys.c

@@ -1277,14 +1277,14 @@ static bool loader_exists(const char * extension) {
     for (i = 0; i < MAX_LOADERS; i++) {
         if (g_file_loader[i].status) {
             if (strcmp(g_file_loader[i].extension, extension) == 0) {
-                return 1;
+                return true;
             }
         }
     }
-    return 0;
+    return false;
 }
 
-static int get_app_ext(const char * path, char * extension) {
+static bool get_app_ext(const char * path, char * extension) {
     char * point = strrchr(path, '.');
     extension[0] = 0;
     if (point != 0) {
@@ -1295,11 +1295,11 @@ static int get_app_ext(const char * path, char * extension) {
                 extension[i] = toupper(c);
             } else {
                 extension[i] = 0;
-                return 1;
+                return true;
             }
         }
     } else {
-        return 0;
+        return false;
     }
 }
 

src/dev/kbd_mo.c

@@ -274,21 +274,21 @@ void kbdmo_flush_out() {
 
 /*
  * Check to see if a BREAK code has been pressed recently
- * If so, return 1 and reset the internal flag.
+ * If so, return true and reset the internal flag.
  *
  * BREAK will be F-ESC on the A2560K
  *
  * Returns:
- * 1 if a BREAK has been pressed since the last check
+ * true if a BREAK has been pressed since the last check
  */
-short kbdmo_break() {
+bool kbdmo_break() {
     if (g_kbdmo_control.status & KBD_STAT_BREAK) {
         /* BREAK was pressed: clear the flag and return a 1 */
         g_kbdmo_control.status &= ~KBD_STAT_BREAK;
-        return 1;
+        return true;
     } else {
         /* BREAK was not pressed: return a 0 */
-        return 0;
+        return false;
     }
 }
 

src/dev/kbd_mo.h

@@ -35,14 +35,14 @@ void kbdmo_set_led_matrix_fill(unsigned short color);
 
 /*
  * Check to see if a BREAK code has been pressed recently
- * If so, return 1 and reset the internal flag.
+ * If so, return true and reset the internal flag.
  *
  * BREAK will be F-ESC on the A2560K
  *
  * Returns:
- * 1 if a BREAK has been pressed since the last check
+ * true if a BREAK has been pressed since the last check
  */
-extern short kbdmo_break();
+extern bool kbdmo_break();
 
 /*
  * Try to retrieve the next scancode from the keyboard.

src/dev/midi.c

@@ -18,37 +18,37 @@ const long midi_timeout = 60;
 /**
  * Wait for data to be ready to read...
  *
- * @return 1 on success, 0 if there is a timeout
+ * @return true on success, false if there is a timeout
  */
-short midi_can_read() {
+bool midi_can_read() {
     long target = timers_jiffies() + midi_timeout;
     do {
         if ((*MIDI_STAT & MIDI_STAT_RX_EMPTY) == 0) {
             // There is data waiting
-            return 1;
+            return true;
         }
     } while (target > timers_jiffies());
 
     // We have waited too long
-    return 0;
+    return false;
 }
 
 /**
  * Wait for the MIDI transmiter to be empty...
  *
- * @return 1 on success, 0 if there is a timeout
+ * @return true on success, false if there is a timeout
  */
 short midi_can_write() {
     long target = timers_jiffies() + midi_timeout;
     do {
         if ((*MIDI_STAT & MIDI_STAT_TX_BUSY) != 0) {
             // The transmit buffer is empty
-            return 1;
+            return true;
         }
     } while (target > timers_jiffies());
 
     // We have waited too long
-    return 0;
+    return false;
 }
 
 /**

src/dev/uart.c

@@ -104,40 +104,24 @@ void uart_init(short uart) {
  * uart = the number of the UART: 0 for COM1, 1 for COM2
  *
  * Returns:
- * non-zero if there is data to read, 0 if there is no data.
+ * true if there is data to read, false if there is no data.
  */
-short uart_has_bytes(short uart) {
+bool uart_has_bytes(short uart) {
     volatile unsigned char * uart_base = uart_get_base(uart);
 
-    if (uart_base) {
+    return uart_base && (uart_base[UART_LSR] & LSR_DATA_AVAIL) ? true : false;
-        if (uart_base[UART_LSR] & LSR_DATA_AVAIL) {
-            return 1;
-        } else {
-            return 0;
-        }
-    } else {
-        return 0;
-    }
 }
 
 /**
  * Return true (non-zero) if the UART transmit FIFO is not full
  *
  * @param uart the number of the UART: 0 for COM1, 1 for COM2
- * @return non-zero if the FIFO can accept a byte, 0 if it is full
+ * @return non-zero if the FIFO can accept a byte, false if it is full
  */
-short uart_can_send(short uart) {
+bool uart_can_send(short uart) {
     volatile unsigned char * uart_base = uart_get_base(uart);
 
-    if (uart_base) {
+    return uart_base && (uart_base[UART_LSR] & LSR_XMIT_EMPTY) ? true : false;
-        if (uart_base[UART_LSR] & LSR_XMIT_EMPTY) {
-            return 1;
-        } else {
-            return 0;
-        }
-    } else {
-        return 0;
-    }
 }
 
 /*

src/dev/uart.h

@@ -47,7 +47,7 @@ extern void uart_init(short uart);
  * Returns:
  * non-zero if there is data to read, 0 if there is no data.
  */
-extern short uart_has_bytes(short uart);
+extern bool uart_has_bytes(short uart);
 
 /*
  * Send a byte to the UART. Blocks until the FIFO is ready to recieve a byte.