feat(ring_buffer): add ring_buffer struct

k/Makefile

@@ -35,7 +35,8 @@ OBJS	= \
 	  idt.o \
 	  isr.o \
 	  pic.o \
-	  pic/keyboard.o
+	  pic/keyboard.o \
+	  utils/ring_buffer.o
 
 
 DEPS = $(OBJS:.o=.d)

k/utils/ring_buffer.c

@@ -0,0 +1,18 @@
+#include "ring_buffer.h"
+
+uint8_t read_entry(struct ring_buffer *buf)
+{
+    if (buf->read >= buf->write)
+        return 0;
+
+    uint8_t data = buf->buffer[buf->read];
+    buf->read = (buf->read + 1) % RING_BUFFER_SIZE;
+
+    return data;
+}
+
+void write_entry(struct ring_buffer *buf, uint8_t entry)
+{
+    buf->buffer[buf->write] = entry;
+    buf->write = (buf->write + 1) % RING_BUFFER_SIZE;
+}

k/utils/ring_buffer.h

@@ -0,0 +1,18 @@
+#ifndef RING_BUFFER_H
+#define RING_BUFFER_H
+
+#define RING_BUFFER_SIZE 32
+
+#include <stdint.h>
+
+struct ring_buffer
+{
+    uint8_t buffer[RING_BUFFER_SIZE];
+    uint8_t read;
+    uint8_t write;
+};
+
+uint8_t read_entry(struct ring_buffer *buf);
+void write_entry(struct ring_buffer *buf, uint8_t entry);
+
+#endif /* !RING_BUFFER_H */