Add stm32-dfu and apm32-dfu to bootloader.mk (qmk#11019)

* Add stm32-dfu and apm32-dfu to bootloader.mk

* Update flashing docs

* Update comment

* Further wordsmithing

bootloader.mk

@@ -20,15 +20,19 @@
 # Sets the bootloader defined in the keyboard's/keymap's rules.mk
 # Current options:
 #
-# halfkay        PJRC Teensy
-# caterina       Pro Micro (Sparkfun/generic)
-# atmel-dfu      Atmel factory DFU
-# lufa-dfu       LUFA DFU
-# qmk-dfu        QMK DFU (LUFA + blinkenlight)
-# bootloadHID    HIDBootFlash compatible (ATmega32A)
-# USBasp         USBaspLoader (ATmega328P)
-# kiibohd        Input:Club Kiibohd bootloader (only used on their boards)
-# stm32duino     STM32Duino (STM32F103x8)
+# AVR:
+#     halfkay     PJRC Teensy
+#     caterina    Pro Micro (Sparkfun/generic)
+#     atmel-dfu   Atmel factory DFU
+#     lufa-dfu    LUFA DFU
+#     qmk-dfu     QMK DFU (LUFA + blinkenlight)
+#     bootloadHID HIDBootFlash compatible (ATmega32A)
+#     USBasp      USBaspLoader (ATmega328P)
+# ARM:
+#     kiibohd     Input:Club Kiibohd bootloader (only used on their boards)
+#     stm32duino  STM32Duino (STM32F103x8)
+#     stm32-dfu   STM32 USB DFU in ROM
+#     apm32-dfu   APM32 USB DFU in ROM
 #
 # BOOTLOADER_SIZE can still be defined manually, but it's recommended
 # you add any possible configuration to this list
@@ -95,6 +99,20 @@ ifdef BOOTLOADER_SIZE
     OPT_DEFS += -DBOOTLOADER_SIZE=$(strip $(BOOTLOADER_SIZE))
 endif
 
+ifeq ($(strip $(BOOTLOADER)), stm32-dfu)
+    OPT_DEFS += -DBOOTLOADER_STM32_DFU
+
+    # Options to pass to dfu-util when flashing
+    DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave
+    DFU_SUFFIX_ARGS ?= -v 0483 -p DF11
+endif
+ifeq ($(strip $(BOOTLOADER)), apm32-dfu)
+    OPT_DEFS += -DBOOTLOADER_APM32_DFU
+
+    # Options to pass to dfu-util when flashing
+    DFU_ARGS ?= -d 314B:0106 -a 0 -s 0x08000000:leave
+    DFU_SUFFIX_ARGS ?= -v 314B -p 0106
+endif
 ifeq ($(strip $(BOOTLOADER)), kiibohd)
     OPT_DEFS += -DBOOTLOADER_KIIBOHD
     ifeq ($(strip $(MCU_ORIG)), MK20DX128)
@@ -104,17 +122,18 @@ ifeq ($(strip $(BOOTLOADER)), kiibohd)
         MCU_LDSCRIPT = MK20DX256BLDR8
     endif
 
+    # Options to pass to dfu-util when flashing
     DFU_ARGS = -d 1C11:B007
     DFU_SUFFIX_ARGS = -v 1C11 -p B007
 endif
-
 ifeq ($(strip $(BOOTLOADER)), stm32duino)
     OPT_DEFS += -DBOOTLOADER_STM32DUINO
     MCU_LDSCRIPT = STM32F103x8_stm32duino_bootloader
     BOARD = STM32_F103_STM32DUINO
     # STM32F103 does NOT have an USB bootloader in ROM (only serial), so setting anything here does not make much sense
     STM32_BOOTLOADER_ADDRESS = 0x80000000
 
-    DFU_ARGS = -d 1EAF:0003 -a2 -R
+    # Options to pass to dfu-util when flashing
+    DFU_ARGS = -d 1EAF:0003 -a 2 -R
     DFU_SUFFIX_ARGS = -v 1EAF -p 0003
 endif