diff --git a/bootloader/rustsbi-k210.bin b/bootloader/rustsbi-k210.bin
deleted file mode 100755
index c53ed1fc198816f8d4a0cfec958eaae3f2976cd0..0000000000000000000000000000000000000000
Binary files a/bootloader/rustsbi-k210.bin and /dev/null differ
diff --git a/os/Makefile b/os/Makefile
index d56bf6b4cc378a9f36d87b072a38dcd6ae996453..21b9614053e72940bca05e7cf28f404796b6192d 100644
--- a/os/Makefile
+++ b/os/Makefile
@@ -6,10 +6,9 @@ KERNEL_BIN := $(KERNEL_ELF).bin
 DISASM_TMP := target/$(TARGET)/$(MODE)/asm
 
 # BOARD
-BOARD ?= qemu
+BOARD := qemu
 SBI ?= rustsbi
 BOOTLOADER := ../bootloader/$(SBI)-$(BOARD).bin
-K210_BOOTLOADER_SIZE := 131072
 
 # Building mode argument
 ifeq ($(MODE), release)
@@ -17,15 +16,7 @@ ifeq ($(MODE), release)
 endif
 
 # KERNEL ENTRY
-ifeq ($(BOARD), qemu)
-	KERNEL_ENTRY_PA := 0x80200000
-else ifeq ($(BOARD), k210)
-	KERNEL_ENTRY_PA := 0x80020000
-endif
-
-# Run K210
-K210-SERIALPORT	= /dev/ttyUSB0
-K210-BURNER = ../tools/kflash.py
+KERNEL_ENTRY_PA := 0x80200000
 
 # Binutils
 OBJDUMP := rust-objdump --arch-name=riscv64
@@ -34,14 +25,7 @@ OBJCOPY := rust-objcopy --binary-architecture=riscv64
 # Disassembly
 DISASM ?= -x
 
-build: env switch-check $(KERNEL_BIN)
-
-switch-check:
-ifeq ($(BOARD), qemu)
-	(which last-qemu) || (rm -f last-k210 && touch last-qemu && make clean)
-else ifeq ($(BOARD), k210)
-	(which last-k210) || (rm -f last-qemu && touch last-k210 && make clean)
-endif
+build: env $(KERNEL_BIN)
 
 env:
 	(rustup target list | grep "riscv64gc-unknown-none-elf (installed)") || rustup target add $(TARGET)
@@ -56,7 +40,7 @@ kernel:
 	@cd ../user && make build
 	@echo Platform: $(BOARD)
 	@cp src/linker-$(BOARD).ld src/linker.ld
-	@cargo build $(MODE_ARG) --features "board_$(BOARD)"
+	@cargo build $(MODE_ARG)
 	@rm src/linker.ld
 
 clean:
@@ -75,21 +59,11 @@ run: run-inner
 	
 
 run-inner: build
-ifeq ($(BOARD),qemu)
 	@qemu-system-riscv64 \
 		-machine virt \
 		-nographic \
 		-bios $(BOOTLOADER) \
 		-device loader,file=$(KERNEL_BIN),addr=$(KERNEL_ENTRY_PA)
-else
-	(which $(K210-BURNER)) || (cd .. && git clone https://github.com/sipeed/kflash.py.git && mv kflash.py tools)
-	@cp $(BOOTLOADER) $(BOOTLOADER).copy
-	@dd if=$(KERNEL_BIN) of=$(BOOTLOADER).copy bs=$(K210_BOOTLOADER_SIZE) seek=1
-	@mv $(BOOTLOADER).copy $(KERNEL_BIN)
-	@sudo chmod 777 $(K210-SERIALPORT)
-	python3 $(K210-BURNER) -p $(K210-SERIALPORT) -b 1500000 $(KERNEL_BIN)
-	python3 -m serial.tools.miniterm --eol LF --dtr 0 --rts 0 --filter direct $(K210-SERIALPORT) 115200
-endif
 
 debug: build
 	@tmux new-session -d \
@@ -103,4 +77,4 @@ gdbserver: build
 gdbclient:
 	@riscv64-unknown-elf-gdb -ex 'file $(KERNEL_ELF)' -ex 'set arch riscv:rv64' -ex 'target remote localhost:1234'
 
-.PHONY: build env kernel clean disasm disasm-vim run-inner switch-check gdbserver gdbclient
+.PHONY: build env kernel clean disasm disasm-vim run-inner gdbserver gdbclient
diff --git a/os/src/linker-k210.ld b/os/src/linker-k210.ld
deleted file mode 100644
index 2ef74ca0ad1934e14e53aacdc4236fd9f3942036..0000000000000000000000000000000000000000
--- a/os/src/linker-k210.ld
+++ /dev/null
@@ -1,48 +0,0 @@
-OUTPUT_ARCH(riscv)
-ENTRY(_start)
-BASE_ADDRESS = 0x80020000;
-
-SECTIONS
-{
-    . = BASE_ADDRESS;
-    skernel = .;
-
-    stext = .;
-    .text : {
-        *(.text.entry)
-        *(.text .text.*)
-    }
-
-    . = ALIGN(4K);
-    etext = .;
-    srodata = .;
-    .rodata : {
-        *(.rodata .rodata.*)
-        *(.srodata .srodata.*)
-    }
-
-    . = ALIGN(4K);
-    erodata = .;
-    sdata = .;
-    .data : {
-        *(.data .data.*)
-        *(.sdata .sdata.*)
-    }
-
-    . = ALIGN(4K);
-    edata = .;
-    .bss : {
-        *(.bss.stack)
-        sbss = .;
-        *(.bss .bss.*)
-        *(.sbss .sbss.*)
-    }
-
-    . = ALIGN(4K);
-    ebss = .;
-    ekernel = .;
-
-    /DISCARD/ : {
-        *(.eh_frame)
-    }
-}
\ No newline at end of file
diff --git a/os/src/sbi.rs b/os/src/sbi.rs
index bda8034d4ff28dbc588d591dbe947fb0806b7e60..9739e3b9ca07a54cc8651281e09c234f53168dc9 100644
--- a/os/src/sbi.rs
+++ b/os/src/sbi.rs
@@ -5,14 +5,13 @@ use core::arch::asm;
 const SBI_SET_TIMER: usize = 0;
 const SBI_CONSOLE_PUTCHAR: usize = 1;
 
-#[cfg(feature = "board_k210")]
-const SBI_SHUTDOWN: usize = 8;
 // const SBI_CONSOLE_GETCHAR: usize = 2;
 // const SBI_CLEAR_IPI: usize = 3;
 // const SBI_SEND_IPI: usize = 4;
 // const SBI_REMOTE_FENCE_I: usize = 5;
 // const SBI_REMOTE_SFENCE_VMA: usize = 6;
 // const SBI_REMOTE_SFENCE_VMA_ASID: usize = 7;
+// const SBI_SHUTDOWN: usize = 8;
 
 ///  handle SBI call with `which` SBI_id and other arguments
 #[inline(always)]
@@ -46,16 +45,8 @@ pub fn console_putchar(c: usize) {
 //     sbi_call(SBI_CONSOLE_GETCHAR, 0, 0, 0)
 // }
 
-#[cfg(feature = "board_qemu")]
 use crate::board::QEMUExit;
 /// use sbi call to shutdown the kernel
 pub fn shutdown() -> ! {
-    #[cfg(feature = "board_k210")]
-    sbi_call(SBI_SHUTDOWN, 0, 0, 0);
-
-    #[cfg(feature = "board_qemu")]
     crate::board::QEMU_EXIT_HANDLE.exit_failure();
-
-    #[cfg(feature = "board_k210")]
-    panic!("It should shutdown!");
 }
diff --git a/os/src/task/mod.rs b/os/src/task/mod.rs
index d3e7b0f0bc1ea0cc188ae8be6a2cdba078ba0548..860fecaf13a7933f92433fe55169972cb038a8b6 100644
--- a/os/src/task/mod.rs
+++ b/os/src/task/mod.rs
@@ -134,14 +134,8 @@ impl TaskManager {
             // go back to user mode
         } else {
             println!("All applications completed!");
-
-            #[cfg(feature = "board_qemu")]
             use crate::board::QEMUExit;
-            #[cfg(feature = "board_qemu")]
             crate::board::QEMU_EXIT_HANDLE.exit_success();
-            
-            #[cfg(feature = "board_k210")]
-            panic!("All applications completed!");
         }
     }
 }