console: locking and tty check

kernel-src/include/kernel/console.h

@@ -2,11 +2,15 @@
 #define _CONSOLE_H
 
 #include <stddef.h>
+#include <stdbool.h>
 #include <kernel/input.h>
+#include <kernel/tty.h>
 
 void console_init();
 void console_putc(char c);
 size_t console_write(char *str, size_t size);
 void console_process_events(input_event_t *events, int count);
+int console_set_lock(bool lock);
+bool console_is_tty(tty_t *p);
 
 #endif

kernel-src/io/console.c

@@ -17,11 +17,24 @@ static semaphore_t input_sem;
 static mutex_t writemutex;
 static thread_t *thread;
 static tty_t *tty;
+static bool locked;
 
 static size_t console_ttywrite(void *internal, char *str, size_t count) {
 	return console_write(str, count);
 }
 
+int console_set_lock(bool lock) {
+	bool expected = !lock;
+	if (!__atomic_compare_exchange_n(&locked, &expected, lock, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST))
+		return EBUSY;
+
+	return 0;
+}
+
+bool console_is_tty(tty_t *p) {
+	return p == tty;
+}
+
 void console_putc(char c) {
 	if (c == '\n') {
 		console_write("\r\n", 2);