Move kflash.py out of proj.

.gitignore

@@ -3,3 +3,4 @@ os/target/*
 os/.idea/*
 os/src/link_app.S
 os/Cargo.lock
+tools/

os/Makefile

@@ -57,7 +57,10 @@ disasm-vim: kernel
 	@vim $(DISASM_TMP)
 	@rm $(DISASM_TMP)
 
-run: run-inner
+run: tools run-inner
+
+tools:
+	(which $(K210-BURNER)) || (cd .. && git clone https://github.com/sipeed/kflash.py.git && mv kflash.py tools)
 
 run-inner: build
 ifeq ($(BOARD),qemu)
@@ -81,4 +84,4 @@ debug: build
 		tmux split-window -h "riscv64-unknown-elf-gdb -ex 'file $(KERNEL_ELF)' -ex 'set arch riscv:rv64' -ex 'target remote localhost:1234'" && \
 		tmux -2 attach-session -d
 
-.PHONY: build env kernel clean disasm disasm-vim run-inner
+.PHONY: build env kernel clean disasm disasm-vim run-inner tools