stlink for st-bootloader: Reset with platform_request_boot()

Both V2 and V21 switch to (ST) bootloader with powered reset.

src/platforms/stlink/Makefile.inc

@@ -13,6 +13,7 @@ LDFLAGS_BOOT := $(LDFLAGS) --specs=nano.specs -lopencm3_stm32f1 \
 	-L../libopencm3/lib
 ifeq ($(ST_BOOTLOADER), 1)
 $(info  Load address 0x08004000 for original ST-LinkV2 Bootloader)
+CFLAGS += -DST_BOOTLOADER
 LDFLAGS = $(LDFLAGS_BOOT) -Wl,-Ttext=0x8004000
 else
 LDFLAGS = $(LDFLAGS_BOOT) -Wl,-Ttext=0x8002000
@@ -34,8 +35,11 @@ SRC += 	cdcacm.c	\
 	traceswoasync.c	\
 	stlink_common.c \
 
+ifeq ($(ST_BOOTLOADER), 1)
+all:	blackmagic.bin blackmagic_dfu.bin blackmagic_dfu.hex
+else
 all:	blackmagic.bin blackmagic_dfu.bin blackmagic_dfu.hex dfu_upgrade.bin dfu_upgrade.hex
-
+endif
 blackmagic_dfu: usbdfu.o dfucore.o dfu_f1.o stlink_common.o
 	@echo "  LD      $@"
 	$(Q)$(CC) $^ -o $@ $(LDFLAGS_BOOT)

src/platforms/stlink/stlink_common.c

@@ -93,6 +93,9 @@ uint32_t detect_rev(void)
 
 void platform_request_boot(void)
 {
+#if defined(DST_BOOTLOADER)
+	scb_reset_system();
+#else
 	uint32_t crl = GPIOA_CRL;
 	/* Assert bootloader marker.
 	 * Enable Pull on GPIOA1. We don't rely on the external pin
@@ -103,4 +106,5 @@ void platform_request_boot(void)
 	crl |= 0x80;
 	GPIOA_CRL = crl;
 	SCB_VTOR = 0;
+#endif
 }