avr/modules/network: added messages.

avr/modules/network/msg/simplemsg-w.asm

@@ -0,0 +1,42 @@
+; ***************************************************************************
+; copyright   : (C) 2025 by Martin Preuss
+; email       : martin@libchipcard.de
+;
+; ***************************************************************************
+; * This file is part of the project "AqHome".                              *
+; * Please see toplevel file COPYING of that project for license details.   *
+; ***************************************************************************
+
+
+; ***************************************************************************
+; code
+
+.cseg
+
+
+
+; ---------------------------------------------------------------------------
+; @routine NETMSG_SimpleMsgWrite
+; Write a simple msg (only code and src address).
+;
+; @param  R16 dest addr
+; @param  R18 msg code
+; @param  X   buffer to write to
+; @param  Y   pointer to network interface data
+; @clobbers R18 (R16, R17, R19, R20, X)
+
+NETMSG_SimpleMsgWrite:
+  st X+, r16                          ; dest address
+  ldi r16, 2                          ; msg code+src address+0 payload bytes
+  st X+, r16                          ; msg len
+  st X+, r18                          ; msg code
+  ldd r16, Y+NET_IFACE_OFFS_ADDRESS
+  st X+, r16                          ; src address
+  
+  sbiw xh:xl, 4  ; go back to beginning of message (1 byte dst addr, 1 byte length, 2 bytes payload)
+  rcall NETMSG_CalcAndAddChecksumByte ; (R16, R17, R18, R19, R20, X)
+  sbiw xh:xl, 5 ; go back to beginning of message (1 byte dst addr, 1 byte length, 2 bytes payload, 1 byte crc)
+  ret
+; @end
+
+