From 530d1e5c28239a55526515f8d21e5580c132ef0d Mon Sep 17 00:00:00 2001
From: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Date: Sat, 22 Sep 2018 15:28:46 +0200
Subject: [PATCH] swlink: Handle force boot on bluepill.

---
 src/platforms/swlink/Makefile.inc |  2 +-
 src/platforms/swlink/usbdfu.c     | 43 +++++++++++++++++++++----------
 2 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/src/platforms/swlink/Makefile.inc b/src/platforms/swlink/Makefile.inc
index 0287d1d..9fed121 100644
--- a/src/platforms/swlink/Makefile.inc
+++ b/src/platforms/swlink/Makefile.inc
@@ -30,7 +30,7 @@ SRC += 	cdcacm.c	\
 
 all:	blackmagic.bin blackmagic_dfu.bin blackmagic_dfu.hex
 
-blackmagic_dfu: usbdfu.o dfucore.o dfu_f1.o
+blackmagic_dfu: usbdfu.o dfucore.o dfu_f1.o platform_common.o
 	@echo "  LD      $@"
 	$(Q)$(CC) $^ -o $@ $(LDFLAGS_BOOT)
 
diff --git a/src/platforms/swlink/usbdfu.c b/src/platforms/swlink/usbdfu.c
index 46ee39d..2f6bb22 100644
--- a/src/platforms/swlink/usbdfu.c
+++ b/src/platforms/swlink/usbdfu.c
@@ -24,6 +24,7 @@
 #include <libopencm3/cm3/scb.h>
 
 #include "usbdfu.h"
+#include "platform.h"
 
 uint32_t app_address = 0x08002000;
 
@@ -43,20 +44,34 @@ void dfu_detach(void)
 int main(void)
 {
 	/* Check the force bootloader pin*/
-	uint16_t pin_b;
-	rcc_periph_clock_enable(RCC_GPIOA);
-	rcc_periph_clock_enable(RCC_GPIOB);
-/* Switch PB5 (SWIM_RST_IN) up */
-	gpio_set(GPIOB, GPIO5);
-	gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ,
-	              GPIO_CNF_OUTPUT_PUSHPULL, GPIO5);
-	gpio_set(GPIOB, GPIO5);
-	pin_b = gpio_get(GPIOB, GPIO6);
-/* Check state on PB6 ((SWIM_RST) and release PB5*/
-	pin_b = gpio_get(GPIOB, GPIO6);
-	gpio_set_mode(GPIOB, GPIO_MODE_INPUT,
-	              GPIO_CNF_INPUT_FLOAT, GPIO5);
-	if(((GPIOA_CRL & 0x40) == 0x40) && pin_b)
+	bool normal_boot = 0;
+	int rev = detect_rev();
+	switch (rev) {
+	case 0:
+		/* For Stlink on  STM8S check that CN7 PIN 4 RESET# is
+		 * forced to GND, Jumper CN7 PIN3/4 is plugged).
+		 * Switch PB5 high. Read PB6 low means jumper plugged.
+		 */
+		gpio_set_mode(GPIOB, GPIO_MODE_INPUT,
+					  GPIO_CNF_INPUT_PULL_UPDOWN, GPIO6);
+		gpio_set(GPIOB, GPIO6);
+		gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ,
+					  GPIO_CNF_OUTPUT_PUSHPULL, GPIO5);
+		while (gpio_get(GPIOB, GPIO5))
+			gpio_clear(GPIOB, GPIO5);
+		while (!gpio_get(GPIOB, GPIO5))
+			gpio_set(GPIOB, GPIO5);
+		normal_boot = (gpio_get(GPIOB, GPIO6));
+		break;
+	case 1:
+		/* Boot0/1 pins have 100k between Jumper and MCU
+		 * and are jumperd to low by default.
+		 * If we read PB2 high, force bootloader entry.*/
+		gpio_set_mode(GPIOB, GPIO_MODE_INPUT,
+					  GPIO_CNF_INPUT_FLOAT, GPIO2);
+		normal_boot = !(gpio_get(GPIOB, GPIO2));
+	}
+	if(((GPIOA_CRL & 0x40) == 0x40) && normal_boot)
 		dfu_jump_app_if_valid();
 
 	dfu_protect(DFU_MODE);