Enable CLI flashing via mdloader

docs/feature_userspace.md

@@ -252,4 +252,4 @@ Also, holding Shift will add the flash target (`:flash`) to the command.  Holdin
 
 And for the boards that lack a shift key, or that you want to always attempt the flashing part, you can add `FLASH_BOOTLOADER = yes` to the `rules.mk` of that keymap.
 
-?> This should flash the newly compiled firmware automatically, using the correct utility, based on the bootloader settings (or default to just generating the HEX file). However, it should be noted that this may not work on all systems. AVRDUDE doesn't work on WSL, namely. And this doesn't support BootloadHID or mdloader. 
+?> This should flash the newly compiled firmware automatically, using the correct utility, based on the bootloader settings (or default to just generating the HEX file). However, it should be noted that this may not work on all systems. AVRDUDE doesn't work on WSL, namely.

lib/python/qmk/cli/flash.py

@@ -18,17 +18,21 @@ def print_bootloader_help():
     """Prints the available bootloaders listed in docs.qmk.fm.
     """
     cli.log.info('Here are the available bootloaders:')
+    cli.echo('\tavrdude')
+    cli.echo('\tbootloadhid')
     cli.echo('\tdfu')
+    cli.echo('\tdfu-util')
+    cli.echo('\tmdloader')
+    cli.echo('\tst-flash')
+    cli.echo('\tst-link-cli')
+    cli.log.info('Enhanced variants for split keyboards:')
+    cli.echo('\tavrdude-split-left')
+    cli.echo('\tavrdude-split-right')
     cli.echo('\tdfu-ee')
     cli.echo('\tdfu-split-left')
     cli.echo('\tdfu-split-right')
-    cli.echo('\tavrdude')
-    cli.echo('\tBootloadHID')
-    cli.echo('\tdfu-util')
     cli.echo('\tdfu-util-split-left')
     cli.echo('\tdfu-util-split-right')
-    cli.echo('\tst-link-cli')
-    cli.echo('\tst-flash')
     cli.echo('For more info, visit https://docs.qmk.fm/#/flashing')
 
 

platforms/arm_atsam/flash.mk

@@ -3,9 +3,20 @@
 # Architecture or project specific options
 #
 
+MDLOADER_CLI ?= mdloader
+
+define EXEC_MDLOADER
+	$(MDLOADER_CLI) --first --download $(BUILD_DIR)/$(TARGET).bin --restart
+endef
+
+mdloader: bin
+	$(call EXEC_MDLOADER)
+
 flash: bin
 ifneq ($(strip $(PROGRAM_CMD)),)
 	$(UNSYNC_OUTPUT_CMD) && $(PROGRAM_CMD)
+else ifeq ($(strip $(ARM_ATSAM)),SAMD51J18A)
+	$(UNSYNC_OUTPUT_CMD) && $(call EXEC_MDLOADER)
 else
 	$(PRINT_OK); $(SILENT) || printf "$(MSG_FLASH_ARCH)"
 endif