1 files changed, 45 insertions, 0 deletions
diff --git a/klippy/chelper/msgblock.h b/klippy/chelper/msgblock.h
new file mode 100644
index 00000000..cce1b2ee
--- /dev/null
+++ b/klippy/chelper/msgblock.h
@@ -0,0 +1,45 @@
+#ifndef MSGBLOCK_H
+#define MSGBLOCK_H
+
+#include <stdint.h> // uint8_t
+#include "list.h" // struct list_node
+
+#define MESSAGE_MIN 5
+#define MESSAGE_MAX 64
+#define MESSAGE_HEADER_SIZE  2
+#define MESSAGE_TRAILER_SIZE 3
+#define MESSAGE_POS_LEN 0
+#define MESSAGE_POS_SEQ 1
+#define MESSAGE_TRAILER_CRC  3
+#define MESSAGE_TRAILER_SYNC 1
+#define MESSAGE_PAYLOAD_MAX (MESSAGE_MAX - MESSAGE_MIN)
+#define MESSAGE_SEQ_MASK 0x0f
+#define MESSAGE_DEST 0x10
+#define MESSAGE_SYNC 0x7E
+
+struct queue_message {
+    int len;
+    uint8_t msg[MESSAGE_MAX];
+    union {
+        // Filled when on a command queue
+        struct {
+            uint64_t min_clock, req_clock;
+        };
+        // Filled when in sent/receive queues
+        struct {
+            double sent_time, receive_time;
+        };
+    };
+    uint64_t notify_id;
+    struct list_node node;
+};
+
+uint16_t msgblock_crc16_ccitt(uint8_t *buf, uint8_t len);
+int msgblock_check(uint8_t *need_sync, uint8_t *buf, int buf_len);
+struct queue_message *message_alloc(void);
+struct queue_message *message_fill(uint8_t *data, int len);
+struct queue_message *message_alloc_and_encode(uint32_t *data, int len);
+void message_free(struct queue_message *qm);
+void message_queue_free(struct list_head *root);
+
+#endif // msgblock.h