🔨 MKS Robin E3 for HAL/STM32 (#21927)

Marlin/src/pins/pins.h

 #elif MB(MKS_ROBIN_PRO)
   #include "stm32f1/pins_MKS_ROBIN_PRO.h"       // STM32F1                                env:mks_robin_pro
 #elif MB(MKS_ROBIN_E3)
-  #include "stm32f1/pins_MKS_ROBIN_E3.h"        // STM32F1                                env:mks_robin_e3
+  #include "stm32f1/pins_MKS_ROBIN_E3.h"        // STM32F1                                env:mks_robin_e3 env:mks_robin_e3_maple
 #elif MB(MKS_ROBIN_E3_V1_1)
   #include "stm32f1/pins_MKS_ROBIN_E3_V1_1.h"   // STM32F1                                env:mks_robin_e3
 #elif MB(MKS_ROBIN_E3D)

Marlin/src/pins/stm32f1/pins_MKS_ROBIN_E3_common.h

 //
 // SD Card
 //
-#define SPI_DEVICE                             2
+#define SPI_DEVICE                          2
+#define ONBOARD_SPI_DEVICE                  2
+#define SDSS                           SD_SS_PIN
+#define SDCARD_CONNECTION                ONBOARD
 #define SD_DETECT_PIN                       PC10
+#define ONBOARD_SD_CS_PIN              SD_SS_PIN
+#define NO_SD_HOST_DRIVE
+
+// TODO: This is the only way to set SPI for SD on STM32 (for now)
+#define ENABLE_SPI2
+#define CUSTOM_SPI_PINS
 #define SD_SCK_PIN                          PB13
 #define SD_MISO_PIN                         PB14
 #define SD_MOSI_PIN                         PB15

buildroot/share/PlatformIO/scripts/stm32_serialbuffer.py

+#
+# stm32_serialbuffer.py
+#
+Import("env")
+
+# Marlin has `RX_BUFFER_SIZE` and `TX_BUFFER_SIZE` to configure the
+# buffer size for receiving and transmitting data respectively.
+# Stm32duino uses another set of defines for the same purpose,
+# so we get the values from the Marlin configuration and set
+# them in `SERIAL_RX_BUFFER_SIZE` and `SERIAL_TX_BUFFER_SIZE`.
+# It is not possible to change the values at runtime, they must
+# be set with build flags.
+#
+# The script will set the value as the default one (64 bytes)
+# or the user-configured one, whichever is higher.
+mf = env["MARLIN_FEATURES"]
+rxBuf = str(max(64, int(mf["RX_BUFFER_SIZE"]) if "RX_BUFFER_SIZE" in mf else 0))
+txBuf = str(max(64, int(mf["TX_BUFFER_SIZE"]) if "TX_BUFFER_SIZE" in mf else 0))
+
+build_flags = env.get('BUILD_FLAGS')
+build_flags.append("-DSERIAL_RX_BUFFER_SIZE=" + rxBuf)
+build_flags.append("-DSERIAL_TX_BUFFER_SIZE=" + txBuf)
+env.Replace(BUILD_FLAGS=build_flags)

ini/stm32f1-maple.ini

 # MKS Robin E3D (STM32F103RCT6) and
 # MKS Robin E3 with TMC2209
 #
-[env:mks_robin_e3]
+[env:mks_robin_e3_maple]
 platform      = ${common_stm32f1.platform}
 extends       = common_stm32f1
 board         = genericSTM32F103RC

ini/stm32f1.ini

   -DADC_RESOLUTION=12
 build_unflags = -std=gnu++11
 src_filter    = ${common.default_src_filter} +<src/HAL/STM32> +<src/HAL/shared/backtrace>
+extra_scripts = ${common.extra_scripts}
+  pre:buildroot/share/PlatformIO/scripts/stm32_serialbuffer.py
 
 #
 # BigTree SKR Mini V1.1 / SKR mini E3 / SKR E3 DIP (STM32F103RCT6 ARM Cortex-M3)
 board_build.core     = stm32
 board_build.variant  = MARLIN_F103Rx
 board_build.ldscript = ldscript.ld
-extra_scripts        = ${common.extra_scripts}
+extra_scripts        = ${common_stm32.extra_scripts}
   pre:buildroot/share/PlatformIO/scripts/generic_create_variant.py
   buildroot/share/PlatformIO/scripts/stm32_bootloader.py
 
   -DENABLE_HWSERIAL3 -DTIMER_SERIAL=TIM5
 build_unflags        = ${common_stm32.build_unflags}
  -DUSBCON -DUSBD_USE_CDC
-extra_scripts        = ${common.extra_scripts}
+extra_scripts        = ${common_stm32.extra_scripts}
   pre:buildroot/share/PlatformIO/scripts/generic_create_variant.py
   buildroot/share/PlatformIO/scripts/stm32_bootloader.py
   buildroot/share/PlatformIO/scripts/mks_encrypt.py
 lib_deps             =
 
 #
+# MKS Robin E3/E3D (STM32F103RCT6) with TMC2209
+#
+[env:mks_robin_e3]
+platform                    = ${common_stm32.platform}
+extends                     = common_STM32F103RC
+build_flags                 = ${common_stm32.build_flags}
+  -DDEBUG_LEVEL=0 -DTIMER_SERVO=TIM5
+build_unflags               = ${common_stm32.build_unflags} -DUSBCON -DUSBD_USE_CDC
+monitor_speed               = 115200
+board_build.offset          = 0x5000
+board_build.encrypt         = Yes
+board_build.firmware        = Robin_e3.bin
+board_upload.offset_address = 0x08005000
+debug_tool                  = stlink
+extra_scripts               = ${env:STM32F103RC.extra_scripts}
+  buildroot/share/PlatformIO/scripts/mks_encrypt.py
+
+#
 # Creality (STM32F103RET6)
 #
 [env:STM32F103RET6_creality]
 board_build.encrypt  = Yes
 board_upload.offset_address = 0x08007000
 build_unflags        = ${common_stm32.build_unflags} -DUSBCON -DUSBD_USE_CDC
-extra_scripts        = ${common.extra_scripts}
+extra_scripts        = ${common_stm32.extra_scripts}
   pre:buildroot/share/PlatformIO/scripts/generic_create_variant.py
   buildroot/share/PlatformIO/scripts/stm32_bootloader.py
   buildroot/share/PlatformIO/scripts/mks_encrypt.py
 build_unflags        = ${common_stm32.build_unflags} -DUSBCON -DUSBD_USE_CDC
 debug_tool           = jlink
 upload_protocol      = jlink
-extra_scripts        = ${common.extra_scripts}
+extra_scripts        = ${common_stm32.extra_scripts}
   pre:buildroot/share/PlatformIO/scripts/generic_create_variant.py
   buildroot/share/PlatformIO/scripts/stm32_bootloader.py
   buildroot/share/PlatformIO/scripts/mks_encrypt.py
 board_build.offset   = 0x10000
 build_flags          = ${common_stm32.build_flags} -DENABLE_HWSERIAL3 -DTIMER_SERIAL=TIM5
 build_unflags        = ${common_stm32.build_unflags} -DUSBCON -DUSBD_USE_CDC
-extra_scripts        = ${common.extra_scripts}
+extra_scripts        = ${common_stm32.extra_scripts}
   pre:buildroot/share/PlatformIO/scripts/generic_create_variant.py
   buildroot/share/PlatformIO/scripts/stm32_bootloader.py