boards/blxxxpill: add support for stm32duino bootloader and for generic St-Link V2.

boards/common/blxxxpill/Makefile.include

@@ -7,6 +7,22 @@ ifeq (dfu-util,$(PROGRAMMER))
 
   # Leave some space at the beginning of the flash for the bootloader
   ROM_OFFSET ?= 0x2000
+
+  # If using STM32duino bootloader, this change is necessary.
+  # Bootloader available at
+  # github.com/rogerclarkmelbourne/STM32duino-bootloader/tree/master/binaries
+  ifeq (stm32duino,$(BOOTLOADER))
+    FFLAGS_OPTS ?= -R
+    FFLAGS ?= --device $(DFU_USB_ID) \
+              --alt $(DFU_ALT) \
+              --download $(FLASHFILE) \
+              $(FFLAGS_OPTS)
+
+    # Flashing may be easier if using a software USB reset.
+    # Future updates may provide USB support for stm32f1 which benefits
+    # from this software reset.
+  endif
+
 else ifeq (openocd,$(PROGRAMMER))
   STLINK_VERSION ?= 2
 endif

boards/common/blxxxpill/dist/openocd-128kib.cfg

@@ -9,9 +9,20 @@ set STOP_WATCHDOG 1
 # STlink Debug clock frequency
 set CLOCK_FREQ 4000
 
+# Some revisions of the Bluepills use a CS32F103C8T6 rather than the STM32Fx
+# MCU, which has a different CPUTAPID than the official STM32F103C8T6. As of
+# 2020-04-09, no upstream support in OpenOCD has been merged. You can uncomment
+# the following line as a workaround until your OpenOCD supports this option:
+#set CPUTAPID 0x2ba01477
+
+# Set the default reset option in cases where "SRST=none" is not used for make
+if { ![info exists SRST_OPT] } {
+   set SRST_OPT srst_only
+}
+
 # use hardware reset, connect under reset
 # connect_assert_srst needed if low power mode application running (WFI...)
-reset_config srst_only srst_nogate connect_assert_srst
+reset_config $SRST_OPT srst_nogate connect_assert_srst
 set CONNECT_UNDER_RESET 1
 
 # brutally overwriting detected flash size with 128KiB (OpenOCD > 0.10.0)

boards/common/blxxxpill/dist/openocd.cfg

@@ -9,9 +9,20 @@ set STOP_WATCHDOG 1
 # STlink Debug clock frequency
 set CLOCK_FREQ 4000
 
+# Some revisions of the Bluepills use a CS32F103C8T6 rather than the STM32Fx
+# MCU, which has a different CPUTAPID than the official STM32F103C8T6. As of
+# 2020-04-09, no upstream support in OpenOCD has been merged. You can uncomment
+# the following line as a workaround until your OpenOCD supports this option:
+#set CPUTAPID 0x2ba01477
+
+# Set the default reset option in cases where "SRST=none" is not used for make
+if { ![info exists SRST_OPT] } {
+   set SRST_OPT srst_only
+}
+
 # use hardware reset, connect under reset
 # connect_assert_srst needed if low power mode application running (WFI...)
-reset_config srst_only srst_nogate connect_assert_srst
+reset_config $SRST_OPT srst_nogate connect_assert_srst
 set CONNECT_UNDER_RESET 1
 
 source [find target/stm32f1x.cfg]

makefiles/tools/openocd-adapters/stlink.inc.mk

@@ -11,6 +11,16 @@ ifneq (,$(DEBUG_ADAPTER_ID))
   OPENOCD_ADAPTER_INIT += -c 'hla_serial $(DEBUG_ADAPTER_ID)'
 endif
 
+
+# Some stlink clones cannot signal reset properly,
+# In this case, use SRST=none
+ifneq (,$(SRST))
+  #Change the adapter init to it
+  # Use STLINK_VERSION to select which stlink version is used
+  OPENOCD_ADAPTER_INIT += \
+    -c 'set SRST_OPT $(SRST)'
+endif
+
 # if no openocd specific configuration file, check for default locations:
 # 1. Using the default dist/openocd.cfg (automatically set by openocd.sh)
 # 2. Using the common cpu specific config file