From e9618f1ba25c0560f490ce831e10d1906fa686b1 Mon Sep 17 00:00:00 2001
From: ldursw <37294448+ldursw@users.noreply.github.com>
Date: Wed, 24 Mar 2021 11:30:19 -0300
Subject: [PATCH] Fix SDIO buffer alignment (#21396)

---
 Marlin/src/feature/binary_stream.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Marlin/src/feature/binary_stream.h b/Marlin/src/feature/binary_stream.h
index 32ebcce2f..ba5d4e8bc 100644
--- a/Marlin/src/feature/binary_stream.h
+++ b/Marlin/src/feature/binary_stream.h
@@ -51,7 +51,12 @@ inline int bs_read_serial(const uint8_t index) {
 
 #if ENABLED(BINARY_STREAM_COMPRESSION)
   static heatshrink_decoder hsd;
-  static uint8_t decode_buffer[512] = {};
+  #ifdef BOTH(ARDUINO_ARCH_STM32F1, SDIO_SUPPORT)
+    // STM32 requires a word-aligned buffer for SD card transfers via DMA
+    static __attribute__((aligned(sizeof(size_t)))) uint8_t decode_buffer[512] = {};
+  #else
+    static uint8_t decode_buffer[512] = {};
+  #endif
 #endif
 
 class SDFileTransferProtocol  {