[bootloader] reset JTAG on boot

Author: sandeepmistry

bootloaders/zero/board_driver_jtag.c

@@ -567,6 +567,12 @@ void jtagDeinit(void)
   jtag.id = -1;
 }
 
+int jtagReload() {
+  int ret = LoadJI(JI_PULSE_NCONFIG);
+  Js_Shiftdr();
+  return ret;
+}
+
 int jtagWriteBuffer(unsigned int address, const uint8_t *data, size_t len)
 {
   int ret = 0;

bootloaders/zero/board_driver_jtag.h

@@ -75,6 +75,7 @@ inline int inpin_get(int pin) { return ((PORT->Group[0].IN.reg & (1<<pin)) != 0)
 extern "C" {
 #endif
 int jtagInit(void);
+int jtagReload(void);
 int jtagWriteBuffer(unsigned int address, const uint8_t* data, size_t len);
 int jtagReadBuffer(unsigned int address, uint8_t* data, size_t len);
 void jtagDeinit(void);

bootloaders/zero/main.c

@@ -194,6 +194,9 @@ int main(void)
   // Enable port mux
   PORT->Group[0].PINCFG[27].reg |= PORT_PINCFG_PMUXEN ;
   clockout(0, 1);
+
+  jtagInit();
+  jtagReload();
 #endif
 
 #if defined(SAM_BA_UART_ONLY)  ||  defined(SAM_BA_BOTH_INTERFACES)