chore(makefile): add an option to control the kernel features

Cargo.toml

@@ -31,7 +31,7 @@ itertools = { version = "0.13.0", default-features = false }
 acpi = "5.2.0"
 
 [features]
-default = ["smp"]
+default = []
 trace_syscall = []
 trace_scheduler = []
 log_trace = ["trace_syscall", "trace_scheduler"]

Makefile.src

@@ -8,7 +8,7 @@ GDB ?= ##GDB##
 FDISK ?= ##FDISK##
 
 QEMU_ARGS ?= -machine q35 -drive id=disk,file=build/boot.img,format=raw,if=none \
-	-device ahci,id=ahci -device ide-hd,drive=disk,bus=ahci.0 -smp 4 \
+	-device ahci,id=ahci -device ide-hd,drive=disk,bus=ahci.0 \
 	-netdev user,id=mynet0,net=192.168.1.0/24,dhcpstart=192.168.1.16 -device e1000e,netdev=mynet0 \
 	-no-reboot -no-shutdown
 
@@ -32,6 +32,10 @@ ifeq ($(MODE),debug)
 MODE := dev
 endif
 
+COMMA := ,
+
+CARGO_FLAGS := --profile $(MODE) --features $(FEATURES)$(if $(SMP),$(COMMA)smp,)
+
 .PHONY: run
 run: build
 	$(QEMU) $(QEMU_ARGS) -display none -serial mon:stdio
@@ -73,19 +77,19 @@ tmux-debug:
 
 .PHONY: kernel
 kernel:
-	cargo build --profile $(MODE)
+	cargo build $(CARGO_FLAGS)
 
 build/kernel.sym: kernel
-	cargo objcopy --profile $(MODE) -- --only-keep-debug build/kernel.sym
+	cargo objcopy $(CARGO_FLAGS) -- --only-keep-debug build/kernel.sym
 
 build/mbr.bin: kernel
-	cargo objcopy --profile $(MODE) -- -O binary -j .mbr build/mbr.bin
+	cargo objcopy $(CARGO_FLAGS) -- -O binary -j .mbr build/mbr.bin
 
 build/stage1.bin: kernel
-	cargo objcopy --profile $(MODE) -- -O binary -j .stage1 build/stage1.bin
+	cargo objcopy $(CARGO_FLAGS) -- -O binary -j .stage1 build/stage1.bin
 
 build/kernel.bin: kernel
-	cargo objcopy --profile $(MODE) -- -O binary --strip-debug \
+	cargo objcopy $(CARGO_FLAGS) -- -O binary --strip-debug \
 		-R .mbr -R .stage1 build/kernel.bin
 
 build/fs.img: init_script.sh