From 75b602811cc46c409dd17904484d80382805cfb1 Mon Sep 17 00:00:00 2001
From: Martin Preuss <martin@aquamaniac.de>
Date: Sat, 17 May 2025 14:22:49 +0200
Subject: [PATCH] added XRAM module.

Module for external SRAM with AtMega8515.
---
 avr/devices/all/includes.asm |   5 ++
 avr/devices/all/modules.asm  |   4 ++
 avr/modules/0BUILD           |   1 +
 avr/modules/xram/0BUILD      |  11 ++++
 avr/modules/xram/main.asm    | 106 +++++++++++++++++++++++++++++++++++
 5 files changed, 127 insertions(+)
 create mode 100644 avr/modules/xram/0BUILD
 create mode 100644 avr/modules/xram/main.asm

diff --git a/avr/devices/all/includes.asm b/avr/devices/all/includes.asm
index 55160d6..b0cfb68 100644
--- a/avr/devices/all/includes.asm
+++ b/avr/devices/all/includes.asm
@@ -24,6 +24,10 @@
 
 .include "modules/basetimer/main.asm"
 
+#ifdef MODULES_XRAM
+.include "modules/xram/main.asm"
+#endif
+
 #ifdef MODULES_NETWORK
 .include "common/crc8.asm"
 .include "common/m_fixedbuffers.asm"
@@ -169,6 +173,7 @@
 .include "apps/network/stats.asm"
 .include "modules/network/msg/sendstats-w.asm"
 .include "modules/network/msg/recvstats-w.asm"
+.include "modules/network/msg/memstats-w.asm"
 .include "modules/network/msg/device-w.asm"
 #endif
 
diff --git a/avr/devices/all/modules.asm b/avr/devices/all/modules.asm
index 90a41f6..571a5f5 100644
--- a/avr/devices/all/modules.asm
+++ b/avr/devices/all/modules.asm
@@ -32,6 +32,10 @@ initModules:
   rcall Timer_Init
 #endif
 
+#ifdef MODULES_XRAM
+  rcall XRAM_Init
+#endif
+
 #ifdef MODULES_LED
   ldi zl, LOW(ledA3Flash)
   ldi zh, HIGH(ledA3Flash)
diff --git a/avr/modules/0BUILD b/avr/modules/0BUILD
index 16da38b..dc51511 100644
--- a/avr/modules/0BUILD
+++ b/avr/modules/0BUILD
@@ -35,6 +35,7 @@
     bootloader
     f_keepup
     valsched
+    xram
   </subdirs>
 
 </gwbuild>
diff --git a/avr/modules/xram/0BUILD b/avr/modules/xram/0BUILD
new file mode 100644
index 0000000..febd367
--- /dev/null
+++ b/avr/modules/xram/0BUILD
@@ -0,0 +1,11 @@
+<?xml?>
+
+<gwbuild>
+
+  <extradist>
+    main.asm
+  </extradist>
+
+</gwbuild>
+
+
diff --git a/avr/modules/xram/main.asm b/avr/modules/xram/main.asm
new file mode 100644
index 0000000..44cd65e
--- /dev/null
+++ b/avr/modules/xram/main.asm
@@ -0,0 +1,106 @@
+; ***************************************************************************
+; 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.   *
+; ***************************************************************************
+
+
+; ***************************************************************************
+; defines
+
+
+
+; ***************************************************************************
+; data
+
+.dseg
+
+xramLastAddress: .byte 2
+
+
+
+
+
+; ***************************************************************************
+; code
+
+.cseg
+
+
+
+; ---------------------------------------------------------------------------
+; @routine XRAM_Init @global
+;
+
+XRAM_Init:
+  clr r16
+  sts xramLastAddress, r16
+  sts xramLastAddress+1, r16
+
+  M_IO_READ r16, MCUCR
+  sbr r16, (1<<SRE)
+  M_IO_WRITE MCUCR, r16
+
+  rcall xramWritePattern
+  rcall xramVerifyPattern
+
+  ret
+; @end
+
+
+; ---------------------------------------------------------------------------
+; @routine XRAM_Fini @global
+;
+
+XRAM_Fini:
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine xramWritePattern
+;
+; Write a pattern to memory (high byte of address)
+
+xramWritePattern:
+  ldi xl, LOW(RAMEND+1)
+  ldi xh, LOW(RAMEND+1)
+xramWritePattern_loop:
+    mov r16, xh
+    st X, r16
+    adiw xh:xl, 1
+  brne xramWritePattern_loop
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine xramVerifyPattern
+;
+; Write a pattern to memory (high byte of address)
+
+xramVerifyPattern:
+  ldi xl, LOW(RAMEND+1)
+  ldi xh, LOW(RAMEND+1)
+xramVerifyPattern_loop:
+    mov r16, xh
+    ld r17, X
+    cp r16, r17
+    brne xramVerifyPattern_end
+    adiw xh:xl, 1
+  brne xramVerifyPattern_loop
+xramVerifyPattern_end:
+  sbiw xh:xl, 1
+  sts xramLastAddress, xl
+  sts xramLastAddress+1, xh
+  ret
+; @end
+
+
+
+