diff --git a/kernel/Makefile b/kernel/Makefile
index 7538688..fcee52d 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -36,9 +36,11 @@ bin := target/$(target)/$(mode)/kernel.bin
 bootimage := target/$(target)/bootimage.bin
 bbl_path := $(PWD)/../riscv-pk
 user_dir := ../user
+k210_lib := ../tools/k210/libkendryte.a
 
 ### export environments ###
 export ARCH = $(arch)
+export BOARD = $(board)
 export SMP = $(smp)
 #export SFSIMG = $(user_dir)/build/user-$(arch).img
 ifeq ($(arch), x86_64)
@@ -247,6 +249,12 @@ else ifeq ($(arch), riscv32)
 		src/arch/riscv32/atomic.patch
 	@cargo xbuild $(build_args)
 else ifeq ($(arch), riscv64)
+ifeq ($(board), k210)
+	@[[ -f $(k210_lib) ]] || wget https://github.com/wangrunji0408/RustOS/releases/download/v0.1/libkendryte.a -O $(k210_lib)
+	@cp src/arch/riscv32/board/k210/linker.ld src/arch/riscv32/boot/linker64.ld
+else
+	@cp src/arch/riscv32/board/u540/linker.ld src/arch/riscv32/boot/linker64.ld
+endif
 	@-patch -p0 -N -b \
 		$(shell rustc --print sysroot)/lib/rustlib/src/rust/src/libcore/sync/atomic.rs \
 		src/arch/riscv32/atomic.patch
diff --git a/kernel/build.rs b/kernel/build.rs
index 5adf240..7573489 100644
--- a/kernel/build.rs
+++ b/kernel/build.rs
@@ -6,8 +6,10 @@ use std::io::{Result, Write};
 
 fn main() {
 	println!("cargo:rerun-if-env-changed=LOG");
+	println!("cargo:rerun-if-env-changed=BOARD");
 
 	let arch: String = std::env::var("ARCH").unwrap();
+	let board: String = std::env::var("BOARD").unwrap();
 	match arch.as_str() {
 		"x86_64" => {
 			gen_vector_asm().unwrap();
@@ -29,6 +31,10 @@ fn main() {
 					.flag("-mabi=lp64")
 					.compile("sfsimg");
 			}
+			if board == "k210" {
+				println!("cargo:rustc-link-search=native={}", "../tools/k210");
+				println!("cargo:rustc-link-lib=static=kendryte");
+			}
 		}
 		"aarch64" => {
 			if let Ok(file_path) = gen_sfsimg_asm() {
diff --git a/kernel/src/arch/riscv32/timer.rs b/kernel/src/arch/riscv32/timer.rs
index 65f0ac9..5b39cb9 100644
--- a/kernel/src/arch/riscv32/timer.rs
+++ b/kernel/src/arch/riscv32/timer.rs
@@ -58,6 +58,7 @@ pub fn set_next() {
 pub fn set_next() {
     unsafe {
         assert_eq!(clint_timer_start(10, true), 0);
+        mstatus::clear_mie();   // mie is set on 'clint_timer_start'
     }
 }
 
diff --git a/tools/k210/kflash.py b/tools/k210/kflash.py
old mode 100644
new mode 100755
index 46910c9..c6e8fae
--- a/tools/k210/kflash.py
+++ b/tools/k210/kflash.py
@@ -15,7 +15,7 @@ import re
 import os
 
 BASH_TIPS = dict(NORMAL='\033[0m',BOLD='\033[1m',DIM='\033[2m',UNDERLINE='\033[4m',
-                    DEFAULT='\033[39', RED='\033[31m', YELLOW='\033[33m', GREEN='\033[32m',
+                    DEFAULT='\033[39m', RED='\033[31m', YELLOW='\033[33m', GREEN='\033[32m',
                     BG_DEFAULT='\033[49m', BG_WHITE='\033[107m')
 
 ERROR_MSG   = BASH_TIPS['RED']+BASH_TIPS['BOLD']+'[ERROR]'+BASH_TIPS['NORMAL']
@@ -465,18 +465,18 @@ class MAIXLoader:
         return data
 
     def reset_to_isp_kd233(self):
-        self._port.dtr = False
-        self._port.rts = False
+        self._port.setDTR (False)
+        self._port.setRTS (False)
         time.sleep(0.01)
         #print('-- RESET to LOW, IO16 to HIGH --')
         # Pull reset down and keep 10ms
-        self._port.dtr = True
-        self._port.rts = False
+        self._port.setDTR (True)
+        self._port.setRTS (False)
         time.sleep(0.01)
         #print('-- IO16 to LOW, RESET to HIGH --')
         # Pull IO16 to low and release reset
-        self._port.rts = True
-        self._port.dtr = False
+        self._port.setRTS (True)
+        self._port.setDTR (False)
         time.sleep(0.01)
 
     def reset_to_isp_dan(self):
@@ -495,18 +495,18 @@ class MAIXLoader:
         time.sleep(0.01)
 
     def reset_to_boot(self):
-        self._port.dtr = False
-        self._port.rts = False
+        self._port.setDTR (False)
+        self._port.setRTS (False)
         time.sleep(0.01)
         #print('-- RESET to LOW --')
         # Pull reset down and keep 10ms
-        self._port.dtr = True
-        self._port.rts = False
+        self._port.setRTS (False)
+        self._port.setDTR (True)
         time.sleep(0.01)
         #print('-- RESET to HIGH, BOOT --')
         # Pull IO16 to low and release reset
-        self._port.rts = False
-        self._port.dtr = False
+        self._port.setRTS (False)
+        self._port.setDTR (False)
         time.sleep(0.01)
 
     def greeting(self):
@@ -709,7 +709,7 @@ class MAIXLoader:
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()
     parser.add_argument("-p", "--port", help="COM Port", default="DEFAULT")
-    parser.add_argument("-c", "--chip", help="SPI Flash type, 1 for in-chip, 0 for on-board", default=1)
+    parser.add_argument("-c", "--chip", help="SPI Flash type, 0 for in-chip, 1 for on-board", default=1)
     parser.add_argument("-b", "--baudrate", type=int, help="UART baudrate for uploading firmware", default=115200)
     parser.add_argument("-l", "--bootloader", help="bootloader bin path", required=False, default=None)
     parser.add_argument("-k", "--key", help="AES key in hex, if you need encrypt your firmware.", required=False, default=None)