From 5038e591eb7b6268dc10de56c17944d5bba96303 Mon Sep 17 00:00:00 2001
From: thisiskeithb <13375512+thisiskeithb@users.noreply.github.com>
Date: Thu, 8 Jun 2023 18:21:33 -0700
Subject: [PATCH 1/2] Add SKR Mini E3 V3.0.1 _xfer Environment

Similar to SKR Mini E3 V3's _xfer environment.
---
 Marlin/src/pins/pins.h |  2 +-
 ini/stm32f4.ini        | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/Marlin/src/pins/pins.h b/Marlin/src/pins/pins.h
index d4ec9f22c0c1..e15aeb5c4b9c 100644
--- a/Marlin/src/pins/pins.h
+++ b/Marlin/src/pins/pins.h
@@ -613,7 +613,7 @@
 #elif MB(BTT_MANTA_M8P_V1_1)
   #include "stm32g0/pins_BTT_MANTA_M8P_V1_1.h"    // STM32G0                              env:STM32G0B1VE_btt env:STM32G0B1VE_btt_xfer
 #elif MB(BTT_SKR_MINI_E3_V3_0_1)
-  #include "stm32f4/pins_BTT_SKR_MINI_E3_V3_0_1.h"// STM32F4                              env:STM32F401RC_btt
+  #include "stm32f4/pins_BTT_SKR_MINI_E3_V3_0_1.h"// STM32F4                              env:STM32F401RC_btt env:STM32F401RC_btt_xfer
 #elif MB(BTT_SKR_MINI_MZ_V1_0)
   #include "stm32f1/pins_BTT_SKR_MINI_MZ_V1_0.h"  // STM32F1                              env:STM32F103RC_btt env:STM32F103RC_btt_USB env:STM32F103RC_btt_maple env:STM32F103RC_btt_USB_maple
 #elif MB(BTT_SKR_E3_DIP)
diff --git a/ini/stm32f4.ini b/ini/stm32f4.ini
index 67c2c6033cb0..3cd415776c64 100644
--- a/ini/stm32f4.ini
+++ b/ini/stm32f4.ini
@@ -743,6 +743,20 @@ build_flags                 = ${stm32_variant.build_flags}
 upload_protocol             = stlink
 debug_tool                  = stlink
 
+#
+# BigTreeTech SKR Mini E3 V3.0.1 (STM32F401RCT6 ARM Cortex-M0+)
+# Custom upload to SD via Marlin with Binary Protocol
+# Requires Marlin with BINARY_FILE_TRANSFER already installed on the target board.
+# If CUSTOM_FIRMWARE_UPLOAD is also installed, Marlin will reboot the board to install the firmware.
+# Currently CUSTOM_FIRMWARE_UPLOAD must also be enabled to use 'xfer' build envs.
+#
+[env:STM32F401RC_btt_xfer]
+extends         = env:STM32F401RC_btt
+build_flags     = ${env:STM32F401RC_btt.build_flags} -DXFER_BUILD
+extra_scripts   = ${env:STM32F401RC_btt.extra_scripts}
+                  pre:buildroot/share/scripts/upload.py
+upload_protocol = custom
+
 #
 # MKS SKIPR v1.0 all-in-one board (STM32F407VE)
 #

From 8bb92a7f9f03171e7e4b8ed556c86b60fd1ccb65 Mon Sep 17 00:00:00 2001
From: thisiskeithb <13375512+thisiskeithb@users.noreply.github.com>
Date: Sat, 10 Jun 2023 11:34:13 -0700
Subject: [PATCH 2/2] SDSUPPORT (HAS_MEDIA) is also required for XFER_BUILDs

SDSUPPORT = HAS_MEDIA, but users shouldn't define HAS_MEDIA directly, so check that SDSUPPORT is enabled.
---
 Marlin/src/inc/SanityCheck.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index 00b532120518..f4d1ff836596 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -3988,8 +3988,8 @@ static_assert(_PLUS_TEST(3), "DEFAULT_MAX_ACCELERATION values must be positive."
 #endif
 
 // Check requirements for upload.py
-#if ENABLED(XFER_BUILD) && !ALL(BINARY_FILE_TRANSFER, CUSTOM_FIRMWARE_UPLOAD)
-  #error "BINARY_FILE_TRANSFER and CUSTOM_FIRMWARE_UPLOAD are required for custom upload."
+#if ENABLED(XFER_BUILD) && !ALL(SDSUPPORT, BINARY_FILE_TRANSFER, CUSTOM_FIRMWARE_UPLOAD)
+  #error "SDSUPPORT, BINARY_FILE_TRANSFER, and CUSTOM_FIRMWARE_UPLOAD are required for custom upload."
 #endif
 
 /**