diff --git a/src/copapy/_binwrite.py b/src/copapy/_binwrite.py
index db1f15f..7ceca66 100644
--- a/src/copapy/_binwrite.py
+++ b/src/copapy/_binwrite.py
@@ -4,19 +4,20 @@ import struct
 
 ByteOrder = Literal['little', 'big']
 
-Command = Enum('Command', [('ALLOCATE_DATA', 1), ('COPY_DATA', 2),
-                           ('ALLOCATE_CODE', 3), ('COPY_CODE', 4),
-                           ('PATCH_FUNC', 0x1000),
-                           ('PATCH_FUNC_ARM32_THM', 0x1005),
-                           ('PATCH_OBJECT', 0x2000),
-                           ('PATCH_OBJECT_HI21', 0x2001),
-                           ('PATCH_OBJECT_ABS', 0x2002),
-                           ('PATCH_OBJECT_REL', 0x2003),
-                           ('PATCH_OBJECT_ARM32_ABS', 0x2004),
-                           ('PATCH_OBJECT_ARM32_ABS_THM', 0x2006),
-                           ('ENTRY_POINT', 7),
-                           ('RUN_PROG', 64), ('READ_DATA', 65),
-                           ('END_COM', 256), ('FREE_MEMORY', 257), ('DUMP_CODE', 258)])
+# header lengths in bytes, command id
+Command = Enum('Command', [('ALLOCATE_DATA', 0x04_0001), ('COPY_DATA', 0x08_0002),
+                           ('ALLOCATE_CODE', 0x04_0003), ('COPY_CODE', 0x08_0004),
+                           ('PATCH_FUNC', 0x10_1000),
+                           ('PATCH_FUNC_ARM32_THM', 0x10_1005),
+                           ('PATCH_OBJECT', 0x10_2000),
+                           ('PATCH_OBJECT_HI21', 0x10_2001),
+                           ('PATCH_OBJECT_ABS', 0x10_2002),
+                           ('PATCH_OBJECT_REL', 0x10_2003),
+                           ('PATCH_OBJECT_ARM32_ABS', 0x10_2004),
+                           ('PATCH_OBJECT_ARM32_ABS_THM', 0x10_2006),
+                           ('ENTRY_POINT', 0x04_0007),
+                           ('RUN_PROG', 0x00_0040), ('READ_DATA', 0x08_0041),
+                           ('END_COM', 0x00_0100), ('FREE_MEMORY', 0x00_0101), ('DUMP_CODE', 0x00_0102)])
 COMMAND_SIZE = 4
 
 
diff --git a/src/coparun/runmem.h b/src/coparun/runmem.h
index 80c4252..897a306 100644
--- a/src/coparun/runmem.h
+++ b/src/coparun/runmem.h
@@ -22,28 +22,40 @@
 #endif
 
 /* Command opcodes used by the parser */
-#define ALLOCATE_DATA     1
-#define COPY_DATA         2
-#define ALLOCATE_CODE     3
-#define COPY_CODE         4
-#define PATCH_FUNC        0x1000
-#define PATCH_FUNC_ARM32_THM   0x1005
-#define PATCH_OBJECT      0x2000
-#define PATCH_OBJECT_HI21 0x2001
-#define PATCH_OBJECT_ABS  0x2002
-#define PATCH_OBJECT_REL  0x2003
-#define PATCH_OBJECT_ARM32_ABS 0x2004
-#define PATCH_OBJECT_ARM32_ABS_THM 0x2006
-#define ENTRY_POINT       7
-#define RUN_PROG         64
-#define READ_DATA        65
-#define END_COM         256
-#define FREE_MEMORY     257
-#define DUMP_CODE       258
+#define ALLOCATE_DATA     0x040001
+#define COPY_DATA         0x080002
+#define ALLOCATE_CODE     0x040003
+#define COPY_CODE         0x080004
+#define PATCH_FUNC        0x101000
+#define PATCH_FUNC_ARM32_THM   0x101005
+#define PATCH_OBJECT      0x102000
+#define PATCH_OBJECT_HI21 0x102001
+#define PATCH_OBJECT_ABS  0x102002
+#define PATCH_OBJECT_REL  0x102003
+#define PATCH_OBJECT_ARM32_ABS 0x102004
+#define PATCH_OBJECT_ARM32_ABS_THM 0x102006
+#define ENTRY_POINT       0x040007
+#define RUN_PROG          0x000040
+#define READ_DATA         0x080041
+#define END_COM           0x000100
+#define FREE_MEMORY       0x000101
+#define DUMP_CODE         0x000102
 
 /* Entry point type */
 typedef int (*entry_point_t)(void);
 
+/* rx_state */
+#define RX_STATE_IDLE    0
+#define RX_STATE_HEADER  1
+#define RX_STATE_DATA    2
+
+/* state_flag */
+#define STATE_FLAG_NONE 0
+#define STATE_FLAG_END_COM 1
+#define STATE_FLAG_DUMP_CODE 2
+#define STATE_FLAG_UNKNOWN_COMMAND -1
+#define STATE_FLAG_MEM_DIST -4   //code and data memory to far apart
+
 /* Struct for run-time memory state */
 typedef struct runmem_s {
     uint8_t *data_memory;            // Pointer to data memory
@@ -52,13 +64,18 @@ typedef struct runmem_s {
     uint32_t executable_memory_len;  // Length of executable memory
     int data_offs;                   // Offset of data memory relative to executable memory
     entry_point_t entr_point;        // Entry point function pointer
+    int32_t rx_state;               // State for receiving commands (idle, header, data)
+    int32_t state_flag;              // Flag for result/error state
+    uint8_t *data_src;
+    uint8_t *data_dest;
+    uint32_t data_size;
 } runmem_t;
 
 /* Command parser: takes a pointer to the command stream and returns
    an error flag (0 on success according to current code) */
-int parse_commands(runmem_t *context, uint8_t *bytes);
+int parse_commands(runmem_t *context, uint8_t *bytes, uint32_t lengths);
 
 /* Free program and data memory */
 void free_memory(runmem_t *context);
 
-#endif /* RUNMEM_H */
\ No newline at end of file
+#endif /* RUNMEM_H */