hc32l110: set pc outside of flash range before flashing

src/target/hc32l110.c

@@ -157,13 +157,24 @@ static void hc32l110_add_flash(target *t, uint32_t flash_size)
  f->blocksize = HC32L110_BLOCKSIZE;
  f->writesize = HC32L110_BLOCKSIZE; // TODO
  f->erased = 0xffU;
+
  f->erase = hc32l110_flash_erase;
  f->write = hc32l110_flash_write;
  f->prepare = hc32l110_flash_prepare;
  f->done = hc32l110_flash_done;
+
  target_add_flash(t, f);
 }
 
+bool hc32l110_enter_flash_mode(target *t)
+{
+ // the MCU required to have PC outside of the flash region to unlock
+ // that one specific region
+
+ uint32_t pc = 0xFFFFFFFE;
+ return t->reg_write(t, REG_PC, &pc, sizeof(pc)) == sizeof(pc);
+}
+
 bool hc32l110_probe(target *t)
 {
  uint32_t flash_size = target_mem_read32(t, HC32L110_ADDR_FLASH_SIZE);
@@ -180,6 +191,8 @@ bool hc32l110_probe(target *t)
  default:
  return false;
  }
+
+ t->enter_flash_mode = hc32l110_enter_flash_mode;
  hc32l110_add_flash(t, flash_size);
  return true;
 }