Add initial support for tinyuf2 bootloader (when hosted on F411 black…

…pill) (qmk#12600)

* Add support for jumping to tinyuf2 bootloader. Adds blackpill UF2 example.

* Update flashing.md

* Update chconf.h

* Update config.h

* Update halconf.h

* Update mcuconf.h

bootloader.mk

@@ -137,3 +137,6 @@ ifeq ($(strip $(BOOTLOADER)), stm32duino)
     DFU_ARGS = -d 1EAF:0003 -a 2 -R
     DFU_SUFFIX_ARGS = -v 1EAF -p 0003
 endif
+ifeq ($(strip $(BOOTLOADER)), tinyuf2)
+    OPT_DEFS += -DBOOTLOADER_TINYUF2
+endif

data/schemas/keyboard.jsonschema

@@ -34,7 +34,7 @@
         },
         "bootloader": {
             "type": "string",
-            "enum": ["atmel-dfu", "bootloadHID", "caterina", "halfkay", "kiibohd", "lufa-dfu", "lufa-ms", "micronucleus", "qmk-dfu", "stm32-dfu", "stm32duino", "unknown", "USBasp"]
+            "enum": ["atmel-dfu", "bootloadHID", "caterina", "halfkay", "kiibohd", "lufa-dfu", "lufa-ms", "micronucleus", "qmk-dfu", "stm32-dfu", "stm32duino", "unknown", "USBasp", "tinyuf2"]
         },
         "diode_direction": {
             "type": "string",

docs/flashing.md

@@ -249,3 +249,29 @@ Flashing sequence:
 2. Wait for the OS to detect the device
 3. Flash a .bin file
 4. Reset the device into application mode (may be done automatically)
+
+## tinyuf2
+
+Keyboards may opt into supporting the tinyuf2 bootloader. This is currently only supported on the F411 blackpill.
+
+The `rules.mk` setting for this bootloader is `tinyuf2`, and can be specified at the keymap or user level.
+
+To ensure compatibility with the tinyuf2 bootloader, make sure this block is present in your `rules.mk`:
+
+```make
+# Bootloader selection
+BOOTLOADER = tinyuf2
+```
+
+Compatible flashers:
+
+* Any application able to copy a file from one place to another, such as _macOS Finder_ or _Windows Explorer_.
+
+Flashing sequence:
+
+1. Enter the bootloader using any of the following methods:
+    * Tap the `RESET` keycode
+    * Double-tap the `nRST` button on the PCB.
+2. Wait for the OS to detect the device
+3. Copy the .uf2 file to the new USB disk
+4. Wait for the keyboard to become available

platforms/chibios/BLACKPILL_STM32_F411/ld/STM32F411xC_tinyuf2.ld

@@ -0,0 +1,89 @@
+/*
+    ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+*/
+
+/*
+ * STM32F411xC memory setup.
+ */
+MEMORY
+{
+    flash0 (rx) : org = 0x08000000 + 64k, len = 256k - 64k /* tinyuf2 bootloader requires app to be located at 64k offset for this MCU */
+    flash1 (rx) : org = 0x00000000, len = 0
+    flash2 (rx) : org = 0x00000000, len = 0
+    flash3 (rx) : org = 0x00000000, len = 0
+    flash4 (rx) : org = 0x00000000, len = 0
+    flash5 (rx) : org = 0x00000000, len = 0
+    flash6 (rx) : org = 0x00000000, len = 0
+    flash7 (rx) : org = 0x00000000, len = 0
+    ram0   (wx) : org = 0x20000000, len = 128k
+    ram1   (wx) : org = 0x00000000, len = 0
+    ram2   (wx) : org = 0x00000000, len = 0
+    ram3   (wx) : org = 0x00000000, len = 0
+    ram4   (wx) : org = 0x00000000, len = 0
+    ram5   (wx) : org = 0x00000000, len = 0
+    ram6   (wx) : org = 0x00000000, len = 0
+    ram7   (wx) : org = 0x00000000, len = 0
+}
+
+/* For each data/text section two region are defined, a virtual region
+   and a load region (_LMA suffix).*/
+
+/* Flash region to be used for exception vectors.*/
+REGION_ALIAS("VECTORS_FLASH", flash0);
+REGION_ALIAS("VECTORS_FLASH_LMA", flash0);
+
+/* Flash region to be used for constructors and destructors.*/
+REGION_ALIAS("XTORS_FLASH", flash0);
+REGION_ALIAS("XTORS_FLASH_LMA", flash0);
+
+/* Flash region to be used for code text.*/
+REGION_ALIAS("TEXT_FLASH", flash0);
+REGION_ALIAS("TEXT_FLASH_LMA", flash0);
+
+/* Flash region to be used for read only data.*/
+REGION_ALIAS("RODATA_FLASH", flash0);
+REGION_ALIAS("RODATA_FLASH_LMA", flash0);
+
+/* Flash region to be used for various.*/
+REGION_ALIAS("VARIOUS_FLASH", flash0);
+REGION_ALIAS("VARIOUS_FLASH_LMA", flash0);
+
+/* Flash region to be used for RAM(n) initialization data.*/
+REGION_ALIAS("RAM_INIT_FLASH_LMA", flash0);
+
+/* RAM region to be used for Main stack. This stack accommodates the processing
+   of all exceptions and interrupts.*/
+REGION_ALIAS("MAIN_STACK_RAM", ram0);
+
+/* RAM region to be used for the process stack. This is the stack used by
+   the main() function.*/
+REGION_ALIAS("PROCESS_STACK_RAM", ram0);
+
+/* RAM region to be used for data segment.*/
+REGION_ALIAS("DATA_RAM", ram0);
+REGION_ALIAS("DATA_RAM_LMA", flash0);
+
+/* RAM region to be used for BSS segment.*/
+REGION_ALIAS("BSS_RAM", ram0);
+
+/* RAM region to be used for the default heap.*/
+REGION_ALIAS("HEAP_RAM", ram0);
+
+/* Generic rules inclusion.*/
+INCLUDE rules.ld
+
+/* TinyUF2 bootloader reset support */
+_board_dfu_dbl_tap = ORIGIN(ram0) + 64k - 4; /* this is based off the linker file for tinyuf2 */
+

platforms/chibios/BLACKPILL_STM32_F411/ld/STM32F411xE_tinyuf2.ld

@@ -0,0 +1,89 @@
+/*
+    ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+*/
+
+/*
+ * STM32F411xE memory setup.
+ */
+MEMORY
+{
+    flash0 (rx) : org = 0x08000000 + 64k, len = 512k - 64k /* tinyuf2 bootloader requires app to be located at 64k offset for this MCU */
+    flash1 (rx) : org = 0x00000000, len = 0
+    flash2 (rx) : org = 0x00000000, len = 0
+    flash3 (rx) : org = 0x00000000, len = 0
+    flash4 (rx) : org = 0x00000000, len = 0
+    flash5 (rx) : org = 0x00000000, len = 0
+    flash6 (rx) : org = 0x00000000, len = 0
+    flash7 (rx) : org = 0x00000000, len = 0
+    ram0   (wx) : org = 0x20000000, len = 128k
+    ram1   (wx) : org = 0x00000000, len = 0
+    ram2   (wx) : org = 0x00000000, len = 0
+    ram3   (wx) : org = 0x00000000, len = 0
+    ram4   (wx) : org = 0x00000000, len = 0
+    ram5   (wx) : org = 0x00000000, len = 0
+    ram6   (wx) : org = 0x00000000, len = 0
+    ram7   (wx) : org = 0x00000000, len = 0
+}
+
+/* For each data/text section two region are defined, a virtual region
+   and a load region (_LMA suffix).*/
+
+/* Flash region to be used for exception vectors.*/
+REGION_ALIAS("VECTORS_FLASH", flash0);
+REGION_ALIAS("VECTORS_FLASH_LMA", flash0);
+
+/* Flash region to be used for constructors and destructors.*/
+REGION_ALIAS("XTORS_FLASH", flash0);
+REGION_ALIAS("XTORS_FLASH_LMA", flash0);
+
+/* Flash region to be used for code text.*/
+REGION_ALIAS("TEXT_FLASH", flash0);
+REGION_ALIAS("TEXT_FLASH_LMA", flash0);
+
+/* Flash region to be used for read only data.*/
+REGION_ALIAS("RODATA_FLASH", flash0);
+REGION_ALIAS("RODATA_FLASH_LMA", flash0);
+
+/* Flash region to be used for various.*/
+REGION_ALIAS("VARIOUS_FLASH", flash0);
+REGION_ALIAS("VARIOUS_FLASH_LMA", flash0);
+
+/* Flash region to be used for RAM(n) initialization data.*/
+REGION_ALIAS("RAM_INIT_FLASH_LMA", flash0);
+
+/* RAM region to be used for Main stack. This stack accommodates the processing
+   of all exceptions and interrupts.*/
+REGION_ALIAS("MAIN_STACK_RAM", ram0);
+
+/* RAM region to be used for the process stack. This is the stack used by
+   the main() function.*/
+REGION_ALIAS("PROCESS_STACK_RAM", ram0);
+
+/* RAM region to be used for data segment.*/
+REGION_ALIAS("DATA_RAM", ram0);
+REGION_ALIAS("DATA_RAM_LMA", flash0);
+
+/* RAM region to be used for BSS segment.*/
+REGION_ALIAS("BSS_RAM", ram0);
+
+/* RAM region to be used for the default heap.*/
+REGION_ALIAS("HEAP_RAM", ram0);
+
+/* Generic rules inclusion.*/
+INCLUDE rules.ld
+
+/* TinyUF2 bootloader reset support */
+_board_dfu_dbl_tap = ORIGIN(ram0) + 64k - 4; /* this is based off the linker file for tinyuf2 */
+

quantum/mcu_selection.mk

@@ -304,7 +304,12 @@ ifneq ($(findstring STM32F411, $(MCU)),)
   # Linker script to use
   # - it should exist either in <chibios>/os/common/ports/ARMCMx/compilers/GCC/ld/
   #   or <keyboard_dir>/ld/
-  MCU_LDSCRIPT ?= STM32F411xE
+  ifeq ($(strip $(BOOTLOADER)), tinyuf2)
+    MCU_LDSCRIPT ?= STM32F411xE_tinyuf2
+    FIRMWARE_FORMAT ?= uf2
+  else
+    MCU_LDSCRIPT ?= STM32F411xE
+  endif
 
   # Startup code to use
   #  - it should exist in <chibios>/os/common/startup/ARMCMx/compilers/GCC/mk/

tmk_core/chibios.mk

@@ -190,6 +190,8 @@ else ifneq ("$(wildcard $(KEYBOARD_PATH_2)/ld/$(MCU_LDSCRIPT).ld)","")
     LDSCRIPT = $(KEYBOARD_PATH_2)/ld/$(MCU_LDSCRIPT).ld
 else ifneq ("$(wildcard $(KEYBOARD_PATH_1)/ld/$(MCU_LDSCRIPT).ld)","")
     LDSCRIPT = $(KEYBOARD_PATH_1)/ld/$(MCU_LDSCRIPT).ld
+else ifneq ("$(wildcard $(TOP_DIR)/platforms/chibios/$(BOARD)/ld/$(MCU_LDSCRIPT).ld)","")
+    LDSCRIPT = $(TOP_DIR)/platforms/chibios/$(BOARD)/ld/$(MCU_LDSCRIPT).ld
 else ifneq ("$(wildcard $(TOP_DIR)/platforms/chibios/common/ld/$(MCU_LDSCRIPT).ld)","")
     LDSCRIPT = $(TOP_DIR)/platforms/chibios/common/ld/$(MCU_LDSCRIPT).ld
 else ifneq ("$(wildcard $(STARTUPLD_CONTRIB)/$(MCU_LDSCRIPT).ld)","")

tmk_core/common/chibios/bootloader.c

@@ -13,7 +13,22 @@
 #    define STM32_BOOTLOADER_DUAL_BANK FALSE
 #endif
 
-#if STM32_BOOTLOADER_DUAL_BANK
+#ifdef BOOTLOADER_TINYUF2
+
+#    define DBL_TAP_MAGIC 0xf01669ef  // From tinyuf2's board_api.h
+
+// defined by linker script
+extern uint32_t _board_dfu_dbl_tap[];
+#    define DBL_TAP_REG _board_dfu_dbl_tap[0]
+
+void bootloader_jump(void) {
+    DBL_TAP_REG = DBL_TAP_MAGIC;
+    NVIC_SystemReset();
+}
+
+void enter_bootloader_mode_if_requested(void) { /* not needed, no two-stage reset */ }
+
+#elif STM32_BOOTLOADER_DUAL_BANK
 
 // Need pin definitions
 #    include "config_common.h"