diff --git a/Makefile b/Makefile
index f657149..2248e15 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,5 @@
+PLATFORM = bluepill
+
 OBJS := src/dirtyjtag.o src/jtag.o src/usb.o src/delay.o src/cmd.o
 
 PREFIX ?= arm-none-eabi
@@ -14,6 +16,7 @@ CFLAGS = -g
 CFLAGS += -Wall -Wextra -Werror
 CFLAGS += -fno-common -ffunction-sections -fdata-sections
 CFLAGS += -std=gnu11
+CFLAGS += -DPLATFORM='HW_$(PLATFORM)'
 
 CPPFLAGS = -MD -g
 CPPFLAGS += -Wall -Wundef
diff --git a/src/jtag.c b/src/jtag.c
index 3840bba..04e5cd8 100644
--- a/src/jtag.c
+++ b/src/jtag.c
@@ -4,33 +4,104 @@
 #include "delay.h"
 #include "jtag.h"
 
-#define JTAG_PORT GPIOA
-#define JTAG_TDI GPIO0
-#define JTAG_TDO GPIO1
-#define JTAG_TCK GPIO2
-#define JTAG_TMS GPIO3
-#define JTAG_TRST GPIO4
-#define JTAG_SRST GPIO5
+#define HW_stlinkv2 0
+#define HW_bluepill 1
+
+#if PLATFORM == HW_stlinkv2 /* Chinese ST-LinkV2 clone */
+
+#define JTAG_PORT_TDI GPIOB
+#define JTAG_PIN_TDI GPIO8
+
+#define JTAG_PORT_TDO GPIOB
+#define JTAG_PIN_TDO GPIO14
+
+#define JTAG_PORT_TCK GPIOA
+#define JTAG_PIN_TCK GPIO5
+
+#define JTAG_PORT_TMS GPIOB
+#define JTAG_PIN_TMS GPIO6
+
+#else /* Blue Pill platform (default) */
+
+#define JTAG_PORT_TDI GPIOA
+#define JTAG_PIN_TDI GPIO0
+
+#define JTAG_PORT_TDO GPIOA
+#define JTAG_PIN_TDO GPIO1
+
+#define JTAG_PORT_TCK GPIOA
+#define JTAG_PIN_TCK GPIO2
+
+#define JTAG_PORT_TMS GPIOA
+#define JTAG_PIN_TMS GPIO3
+
+#define JTAG_PORT_TRST GPIOA
+#define JTAG_PIN_TRST GPIO4
+
+#define JTAG_PORT_SRST GPIOA
+#define JTAG_PIN_SRST GPIO5
+
+#endif
+
+#if !defined(JTAG_PORT_TDI) || \
+  !defined(JTAG_PORT_TDO) || \
+  !defined(JTAG_PORT_TMS) || \
+  !defined(JTAG_PORT_TCK)
+#error "Not enough pins defined for proper JTAG operation"
+#endif
 
 static uint32_t period = 1;
 
 void jtag_init(void) {
   /* GPIO configuration */
-  gpio_set_mode(JTAG_PORT,
+  gpio_set_mode(JTAG_PORT_TCK,
 		GPIO_MODE_OUTPUT_50_MHZ,
 		GPIO_CNF_OUTPUT_PUSHPULL,
-		JTAG_TCK | JTAG_TDI | JTAG_TMS | JTAG_SRST | JTAG_TRST);
-  gpio_set_mode(JTAG_PORT,
+		JTAG_PIN_TCK);
+  gpio_set_mode(JTAG_PORT_TDI,
+		GPIO_MODE_OUTPUT_50_MHZ,
+		GPIO_CNF_OUTPUT_PUSHPULL,
+		JTAG_PIN_TDI);
+  gpio_set_mode(JTAG_PORT_TMS,
+		GPIO_MODE_OUTPUT_50_MHZ,
+		GPIO_CNF_OUTPUT_PUSHPULL,
+		JTAG_PIN_TMS);
+  gpio_set_mode(JTAG_PORT_TDO,
 		GPIO_MODE_INPUT,
 		GPIO_CNF_INPUT_PULL_UPDOWN,
-		JTAG_TDO);
+		JTAG_PIN_TDO);
+#ifdef JTAG_PORT_SRST
+  gpio_set_mode(JTAG_PORT_SRST,
+		GPIO_MODE_OUTPUT_50_MHZ,
+		GPIO_CNF_OUTPUT_PUSHPULL,
+		JTAG_PIN_SRST);
+#endif
+#ifdef JTAG_PORT_TRST
+  gpio_set_mode(JTAG_PORT_TRST,
+		GPIO_MODE_OUTPUT_50_MHZ,
+		GPIO_CNF_OUTPUT_PUSHPULL,
+		JTAG_PIN_TRST);
+#endif
+#if PLATFORM == HW_stlinkv2
+  /* Put weird STLinkV2 clone pull pins in high impedance state */
+  gpio_set_mode(GPIOB, GPIO_MODE_INPUT,
+		GPIO_CNF_INPUT_FLOAT,
+		GPIO5 | GPIO7 | GPIO9 | GPIO10 | GPIO12);
+#endif
 
   /* Set default pin state */
-  gpio_clear(JTAG_PORT, JTAG_TCK | JTAG_TMS | JTAG_TDI);
-  gpio_set(JTAG_PORT, JTAG_TRST | JTAG_SRST);
+  gpio_clear(JTAG_PORT_TCK, JTAG_PIN_TCK);
+  gpio_clear(JTAG_PORT_TMS, JTAG_PIN_TMS);
+  gpio_clear(JTAG_PORT_TDI, JTAG_PIN_TDI);
+#ifdef JTAG_PORT_TRST
+  gpio_set(JTAG_PORT_TRST, JTAG_PIN_TRST);
+#endif
+#ifdef JTAG_PORT_SRST
+  gpio_set(JTAG_PORT_SRST, JTAG_PIN_SRST);
+#endif
 
   /* Set pull-down on TDO */
-  gpio_clear(JTAG_PORT, JTAG_TDO);
+  gpio_clear(JTAG_PORT_TDO, JTAG_PIN_TDO);
 }
 
 void jtag_set_frequency(uint32_t frequency) {
@@ -43,56 +114,64 @@ void jtag_set_frequency(uint32_t frequency) {
 void jtag_clock(void) {
   delay_us(period/2);
   
-  gpio_set(JTAG_PORT, JTAG_TCK);
+  gpio_set(JTAG_PORT_TCK, JTAG_PIN_TCK);
 
   delay_us(period);
 
-  gpio_clear(JTAG_PORT, JTAG_TCK);
+  gpio_clear(JTAG_PORT_TCK, JTAG_PIN_TCK);
   delay_us(period/2);
 }
 
 void jtag_set_tck(uint8_t value) {
   if (value) {
-    gpio_set(JTAG_PORT, JTAG_TCK);
+    gpio_set(JTAG_PORT_TCK, JTAG_PIN_TCK);
   } else {
-    gpio_clear(JTAG_PORT, JTAG_TCK);
+    gpio_clear(JTAG_PORT_TCK, JTAG_PIN_TCK);
   }
 }
 
 void jtag_set_tms(uint8_t value) {
   if (value) {
-    gpio_set(JTAG_PORT, JTAG_TMS);
+    gpio_set(JTAG_PORT_TMS, JTAG_PIN_TMS);
   } else {
-    gpio_clear(JTAG_PORT, JTAG_TMS);
+    gpio_clear(JTAG_PORT_TMS, JTAG_PIN_TMS);
   }
 }
 
 void jtag_set_tdi(uint8_t value) {
   if (value) {
-    gpio_set(JTAG_PORT, JTAG_TDI);
+    gpio_set(JTAG_PORT_TDI, JTAG_PIN_TDI);
   } else {
-    gpio_clear(JTAG_PORT, JTAG_TDI);
+    gpio_clear(JTAG_PORT_TDI, JTAG_PIN_TDI);
   }
 }
 
 uint8_t jtag_get_tdo(void) {
-  return gpio_get(JTAG_PORT, JTAG_TDO) ? 1 : 0;
+  return gpio_get(JTAG_PORT_TDO, JTAG_PIN_TDO) ? 1 : 0;
 }
 
 void jtag_set_trst(uint8_t value) {
+#ifdef JTAG_PORT_TRST
   if (value) {
-    gpio_set(JTAG_PORT, JTAG_TRST);
+    gpio_set(JTAG_PORT_TRST, JTAG_PIN_TRST);
   } else {
-    gpio_clear(JTAG_PORT, JTAG_TRST);
+    gpio_clear(JTAG_PORT_TRST, JTAG_PIN_TRST);
   }
+#else
+  (void)value;
+#endif
 }
 
 void jtag_set_srst(uint8_t value) {
+#ifdef JTAG_PORT_SRST
   if (value) {
-    gpio_set(JTAG_PORT, JTAG_SRST);
+    gpio_set(JTAG_PORT_SRST, JTAG_PIN_SRST);
   } else {
-    gpio_clear(JTAG_PORT, JTAG_SRST);
+    gpio_clear(JTAG_PORT_SRST, JTAG_PIN_SRST);
   }
+#else
+  (void)value;
+#endif
 }
 
 void jtag_transfer(uint16_t length, const uint8_t *in, uint8_t *out) {