diff --git a/.gitignore b/.gitignore
index 9fc90c58..32f926a7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@ os/src/link_app.S
 os/src/linker.ld
 os/last-*
 os/Cargo.lock
+os/.gdb_history
 user/build
 user/target/*
 user/.idea/*
diff --git a/bootloader/rustsbi-k210.bin b/bootloader/rustsbi-k210.bin
index c53ed1fc..158bfa4c 100755
Binary files a/bootloader/rustsbi-k210.bin and b/bootloader/rustsbi-k210.bin differ
diff --git a/bootloader/rustsbi-qemu.bin b/bootloader/rustsbi-qemu.bin
index ddbf336a..76e0e59e 100755
Binary files a/bootloader/rustsbi-qemu.bin and b/bootloader/rustsbi-qemu.bin differ
diff --git a/os/Makefile b/os/Makefile
index 505d37ec..f3e40c1a 100644
--- a/os/Makefile
+++ b/os/Makefile
@@ -1,6 +1,6 @@
 # Building
 TARGET := riscv64gc-unknown-none-elf
-MODE := release
+MODE := debug
 KERNEL_ELF := target/$(TARGET)/$(MODE)/os
 KERNEL_BIN := $(KERNEL_ELF).bin
 DISASM_TMP := target/$(TARGET)/$(MODE)/asm
@@ -11,6 +11,11 @@ SBI ?= rustsbi
 BOOTLOADER := ../bootloader/$(SBI)-$(BOARD).bin
 K210_BOOTLOADER_SIZE := 131072
 
+# Building mode argument
+ifeq ($(MODE), release)
+	MODE_ARG := --release
+endif
+
 # KERNEL ENTRY
 ifeq ($(BOARD), qemu)
 	KERNEL_ENTRY_PA := 0x80200000
@@ -51,7 +56,7 @@ kernel:
 	@cd ../user && make build
 	@echo Platform: $(BOARD)
 	@cp src/linker-$(BOARD).ld src/linker.ld
-	@cargo build --release --features "board_$(BOARD)"
+	@cargo build $(MODE_ARG) --features "board_$(BOARD)"
 	@rm src/linker.ld
 
 clean:
@@ -92,4 +97,10 @@ 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 switch-check
+gdbserver: build
+	@qemu-system-riscv64 -machine virt -nographic -bios $(BOOTLOADER) -device loader,file=$(KERNEL_BIN),addr=$(KERNEL_ENTRY_PA) -s -S
+
+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
diff --git a/rust-toolchain b/rust-toolchain
index 925656db..abcacd9b 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-nightly-2022-01-19
+nightly-2022-04-11