feat: Framework to handle INCP messages

app/src/msg_buf.h

@@ -0,0 +1,36 @@
+#ifndef MSG_BUF_H_
+#define MSG_BUF_H_
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+
+
+#define MAX_LEN (0xFFFE)
+
+
+typedef uint32_t err_t;
+#define ERR_OK ((err_t)0)
+#define ERR_ARGS ((err_t)1)
+#define ERR_FULL ((err_t)2)
+#define ERR_EMPTY ((err_t)3)
+
+
+// Message buffer
+// Variable-sized entry circular buffer
+// No modulo, contiguous memory read/write
+// Maximum message size 0xFFFE (0xFFFF is padding)
+// Minimum message size 0
+// NOT thread/task safe
+typedef struct msg_buf {
+	uint8_t *storage;
+	uint32_t capacity;
+	uint32_t head, count;
+} msg_buf_t;
+
+int msg_buf_init(msg_buf_t *buf, void *storage, uint32_t capacity);
+int msg_buf_push(msg_buf_t *buf, void *data, uint32_t len);
+int msg_buf_peek(msg_buf_t *buf, void **ptr, uint32_t *len);
+int msg_buf_pop(msg_buf_t *buf);
+
+#endif