diff --git a/.githooks/pre-commit b/.githooks/pre-commit
index 9f1da522..64502afd 100755
--- a/.githooks/pre-commit
+++ b/.githooks/pre-commit
@@ -13,6 +13,8 @@ source_files_exts = ['.S', '.rs', '.rb']
 
 staged_files = `git --no-pager diff --name-only --cached --diff-filter=d`.split(/\n/)
 staged_files.select! do |f|
+    next if f.include?('build.rs')
+
     f.include?('Makefile') ||
         f.include?('Dockerfile') ||
         source_files_exts.include?(File.extname(f))
diff --git a/01_wait_forever/Makefile b/01_wait_forever/Makefile
index ffb3c79d..8abfde11 100644
--- a/01_wait_forever/Makefile
+++ b/01_wait_forever/Makefile
@@ -24,7 +24,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -51,14 +52,12 @@ EXEC_QEMU = $(QEMU_BINARY) -M $(QEMU_MACHINE_TYPE)
 
 .PHONY: all doc qemu clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -77,11 +76,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/01_wait_forever/build.rs b/01_wait_forever/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/01_wait_forever/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/02_runtime_init/Makefile b/02_runtime_init/Makefile
index ffb3c79d..8abfde11 100644
--- a/02_runtime_init/Makefile
+++ b/02_runtime_init/Makefile
@@ -24,7 +24,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -51,14 +52,12 @@ EXEC_QEMU = $(QEMU_BINARY) -M $(QEMU_MACHINE_TYPE)
 
 .PHONY: all doc qemu clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -77,11 +76,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/02_runtime_init/build.rs b/02_runtime_init/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/02_runtime_init/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/02_runtime_init/kernel8.img b/02_runtime_init/kernel8.img
old mode 100755
new mode 100644
diff --git a/03_hacky_hello_world/Makefile b/03_hacky_hello_world/Makefile
index dd6aaab5..da24d662 100644
--- a/03_hacky_hello_world/Makefile
+++ b/03_hacky_hello_world/Makefile
@@ -24,7 +24,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -51,14 +52,12 @@ EXEC_QEMU = $(QEMU_BINARY) -M $(QEMU_MACHINE_TYPE)
 
 .PHONY: all doc qemu clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -77,11 +76,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/03_hacky_hello_world/build.rs b/03_hacky_hello_world/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/03_hacky_hello_world/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/04_zero_overhead_abstraction/Makefile b/04_zero_overhead_abstraction/Makefile
index dd6aaab5..da24d662 100644
--- a/04_zero_overhead_abstraction/Makefile
+++ b/04_zero_overhead_abstraction/Makefile
@@ -24,7 +24,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -51,14 +52,12 @@ EXEC_QEMU = $(QEMU_BINARY) -M $(QEMU_MACHINE_TYPE)
 
 .PHONY: all doc qemu clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -77,11 +76,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/04_zero_overhead_abstraction/build.rs b/04_zero_overhead_abstraction/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/04_zero_overhead_abstraction/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/05_safe_globals/Makefile b/05_safe_globals/Makefile
index dd6aaab5..da24d662 100644
--- a/05_safe_globals/Makefile
+++ b/05_safe_globals/Makefile
@@ -24,7 +24,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -51,14 +52,12 @@ EXEC_QEMU = $(QEMU_BINARY) -M $(QEMU_MACHINE_TYPE)
 
 .PHONY: all doc qemu clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -77,11 +76,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/05_safe_globals/build.rs b/05_safe_globals/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/05_safe_globals/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/06_drivers_gpio_uart/Makefile b/06_drivers_gpio_uart/Makefile
index dd6aaab5..da24d662 100644
--- a/06_drivers_gpio_uart/Makefile
+++ b/06_drivers_gpio_uart/Makefile
@@ -24,7 +24,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -51,14 +52,12 @@ EXEC_QEMU = $(QEMU_BINARY) -M $(QEMU_MACHINE_TYPE)
 
 .PHONY: all doc qemu clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -77,11 +76,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/06_drivers_gpio_uart/build.rs b/06_drivers_gpio_uart/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/06_drivers_gpio_uart/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/07_uart_chainloader/Makefile b/07_uart_chainloader/Makefile
index 46d7ae53..f9caa6a1 100644
--- a/07_uart_chainloader/Makefile
+++ b/07_uart_chainloader/Makefile
@@ -32,7 +32,8 @@ else ifeq ($(BSP),rpi4)
     CHAINBOOT_DEMO_PAYLOAD = demo_payload_rpi4.img
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -69,14 +70,12 @@ EXEC_MINIPUSH = ruby ../utils/minipush.rb
 
 .PHONY: all doc qemu qemuasm chainboot clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -101,11 +100,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/07_uart_chainloader/README.md b/07_uart_chainloader/README.md
index 51544dfa..99be098d 100644
--- a/07_uart_chainloader/README.md
+++ b/07_uart_chainloader/README.md
@@ -126,8 +126,8 @@ diff -uNr 06_drivers_gpio_uart/Makefile 07_uart_chainloader/Makefile
 +    CHAINBOOT_DEMO_PAYLOAD = demo_payload_rpi4.img
  endif
 
- SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
-@@ -44,12 +52,22 @@
+ # Export for build.rs
+@@ -45,12 +53,22 @@
 
  DOCKER_IMAGE         = rustembedded/osdev-utils
  DOCKER_CMD           = docker run -it --rm -v $(shell pwd):/work/tutorial -w /work/tutorial
@@ -150,9 +150,9 @@ diff -uNr 06_drivers_gpio_uart/Makefile 07_uart_chainloader/Makefile
 +
 +.PHONY: all doc qemu qemuasm chainboot clippy clean readelf objdump nm
 
- all: clean $(OUTPUT)
-
-@@ -64,13 +82,19 @@
+ all:
+ 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
+@@ -63,13 +81,19 @@
  	$(DOC_CMD) --document-private-items --open
 
  ifeq ($(QEMU_MACHINE_TYPE),)
diff --git a/07_uart_chainloader/build.rs b/07_uart_chainloader/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/07_uart_chainloader/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/08_timestamps/Makefile b/08_timestamps/Makefile
index 4b18773a..a765953e 100644
--- a/08_timestamps/Makefile
+++ b/08_timestamps/Makefile
@@ -30,7 +30,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -67,14 +68,12 @@ EXEC_MINIPUSH = ruby ../utils/minipush.rb
 
 .PHONY: all doc qemu chainboot clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -96,11 +95,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/08_timestamps/README.md b/08_timestamps/README.md
index bcbb663f..ace4428a 100644
--- a/08_timestamps/README.md
+++ b/08_timestamps/README.md
@@ -65,17 +65,17 @@ diff -uNr 07_uart_chainloader/Makefile 08_timestamps/Makefile
 +    RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
  endif
 
- SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
-@@ -67,7 +65,7 @@
+ # Export for build.rs
+@@ -68,7 +66,7 @@
  EXEC_QEMU     = $(QEMU_BINARY) -M $(QEMU_MACHINE_TYPE)
  EXEC_MINIPUSH = ruby ../utils/minipush.rb
 
 -.PHONY: all doc qemu qemuasm chainboot clippy clean readelf objdump nm
 +.PHONY: all doc qemu chainboot clippy clean readelf objdump nm
 
- all: clean $(OUTPUT)
-
-@@ -82,18 +80,15 @@
+ all:
+ 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
+@@ -81,18 +79,15 @@
  	$(DOC_CMD) --document-private-items --open
 
  ifeq ($(QEMU_MACHINE_TYPE),)
diff --git a/08_timestamps/build.rs b/08_timestamps/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/08_timestamps/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/09_hw_debug_JTAG/Makefile b/09_hw_debug_JTAG/Makefile
index 24dd68c2..681f90f9 100644
--- a/09_hw_debug_JTAG/Makefile
+++ b/09_hw_debug_JTAG/Makefile
@@ -34,7 +34,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -78,14 +79,12 @@ EXEC_MINIPUSH = ruby ../utils/minipush.rb
 
 .PHONY: all doc qemu chainboot jtagboot openocd gdb gdb-opt0 clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -113,10 +112,10 @@ define gen_gdb
     @$(DOCKER_GDB) gdb-multiarch -q kernel_for_jtag
 endef
 
-gdb: clean $(SOURCES)
+gdb:
 	$(call gen_gdb,-C debuginfo=2)
 
-gdb-opt0: clean $(SOURCES)
+gdb-opt0:
 	$(call gen_gdb,-C debuginfo=2 -C opt-level=0)
 
 clippy:
@@ -125,11 +124,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/09_hw_debug_JTAG/README.md b/09_hw_debug_JTAG/README.md
index 16d1fe3c..66dedfe3 100644
--- a/09_hw_debug_JTAG/README.md
+++ b/09_hw_debug_JTAG/README.md
@@ -323,7 +323,7 @@ diff -uNr 08_timestamps/Makefile 09_hw_debug_JTAG/Makefile
      LINKER_FILE       = src/bsp/raspberrypi/link.ld
      RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
  endif
-@@ -51,21 +55,28 @@
+@@ -52,21 +56,28 @@
  DOCKER_IMAGE         = rustembedded/osdev-utils
  DOCKER_CMD           = docker run -it --rm -v $(shell pwd):/work/tutorial -w /work/tutorial
  DOCKER_ARG_DIR_UTILS = -v $(shell pwd)/../utils:/work/utils
@@ -351,9 +351,9 @@ diff -uNr 08_timestamps/Makefile 09_hw_debug_JTAG/Makefile
 -.PHONY: all doc qemu chainboot clippy clean readelf objdump nm
 +.PHONY: all doc qemu chainboot jtagboot openocd gdb gdb-opt0 clippy clean readelf objdump nm
 
- all: clean $(OUTPUT)
-
-@@ -90,6 +101,24 @@
+ all:
+ 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
+@@ -89,6 +100,24 @@
  chainboot: all
  	@$(DOCKER_CHAINBOOT) $(EXEC_MINIPUSH) $(DEV_SERIAL) $(OUTPUT)
 
@@ -369,10 +369,10 @@ diff -uNr 08_timestamps/Makefile 09_hw_debug_JTAG/Makefile
 +    @$(DOCKER_GDB) gdb-multiarch -q kernel_for_jtag
 +endef
 +
-+gdb: clean $(SOURCES)
++gdb:
 +	$(call gen_gdb,-C debuginfo=2)
 +
-+gdb-opt0: clean $(SOURCES)
++gdb-opt0:
 +	$(call gen_gdb,-C debuginfo=2 -C opt-level=0)
 +
  clippy:
diff --git a/09_hw_debug_JTAG/build.rs b/09_hw_debug_JTAG/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/09_hw_debug_JTAG/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/10_privilege_level/Makefile b/10_privilege_level/Makefile
index 24dd68c2..681f90f9 100644
--- a/10_privilege_level/Makefile
+++ b/10_privilege_level/Makefile
@@ -34,7 +34,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -78,14 +79,12 @@ EXEC_MINIPUSH = ruby ../utils/minipush.rb
 
 .PHONY: all doc qemu chainboot jtagboot openocd gdb gdb-opt0 clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -113,10 +112,10 @@ define gen_gdb
     @$(DOCKER_GDB) gdb-multiarch -q kernel_for_jtag
 endef
 
-gdb: clean $(SOURCES)
+gdb:
 	$(call gen_gdb,-C debuginfo=2)
 
-gdb-opt0: clean $(SOURCES)
+gdb-opt0:
 	$(call gen_gdb,-C debuginfo=2 -C opt-level=0)
 
 clippy:
@@ -125,11 +124,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/10_privilege_level/build.rs b/10_privilege_level/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/10_privilege_level/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/11_virtual_memory/Makefile b/11_virtual_memory/Makefile
index 24dd68c2..681f90f9 100644
--- a/11_virtual_memory/Makefile
+++ b/11_virtual_memory/Makefile
@@ -34,7 +34,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -78,14 +79,12 @@ EXEC_MINIPUSH = ruby ../utils/minipush.rb
 
 .PHONY: all doc qemu chainboot jtagboot openocd gdb gdb-opt0 clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -113,10 +112,10 @@ define gen_gdb
     @$(DOCKER_GDB) gdb-multiarch -q kernel_for_jtag
 endef
 
-gdb: clean $(SOURCES)
+gdb:
 	$(call gen_gdb,-C debuginfo=2)
 
-gdb-opt0: clean $(SOURCES)
+gdb-opt0:
 	$(call gen_gdb,-C debuginfo=2 -C opt-level=0)
 
 clippy:
@@ -125,11 +124,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/11_virtual_memory/build.rs b/11_virtual_memory/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/11_virtual_memory/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/12_exceptions_part1_groundwork/Makefile b/12_exceptions_part1_groundwork/Makefile
index 24dd68c2..681f90f9 100644
--- a/12_exceptions_part1_groundwork/Makefile
+++ b/12_exceptions_part1_groundwork/Makefile
@@ -34,7 +34,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -78,14 +79,12 @@ EXEC_MINIPUSH = ruby ../utils/minipush.rb
 
 .PHONY: all doc qemu chainboot jtagboot openocd gdb gdb-opt0 clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -113,10 +112,10 @@ define gen_gdb
     @$(DOCKER_GDB) gdb-multiarch -q kernel_for_jtag
 endef
 
-gdb: clean $(SOURCES)
+gdb:
 	$(call gen_gdb,-C debuginfo=2)
 
-gdb-opt0: clean $(SOURCES)
+gdb-opt0:
 	$(call gen_gdb,-C debuginfo=2 -C opt-level=0)
 
 clippy:
@@ -125,11 +124,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/12_exceptions_part1_groundwork/build.rs b/12_exceptions_part1_groundwork/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/12_exceptions_part1_groundwork/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/13_integrated_testing/Makefile b/13_integrated_testing/Makefile
index d2800434..5e25ab07 100644
--- a/13_integrated_testing/Makefile
+++ b/13_integrated_testing/Makefile
@@ -36,6 +36,9 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
+# Export for build.rs
+export LINKER_FILE
+
 # Testing-specific arguments
 ifdef TEST
     ifeq ($(TEST),unit)
@@ -47,8 +50,6 @@ endif
 
 QEMU_MISSING_STRING = "This board is not yet supported for QEMU."
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
-
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
 
@@ -94,14 +95,12 @@ EXEC_MINIPUSH = ruby ../utils/minipush.rb
 
 .PHONY: all doc qemu chainboot jtagboot openocd gdb gdb-opt0 clippy clean readelf objdump nm test
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -122,7 +121,7 @@ define KERNEL_TEST_RUNNER
 endef
 
 export KERNEL_TEST_RUNNER
-test: $(SOURCES)
+test:
 	@mkdir -p target
 	@echo "$$KERNEL_TEST_RUNNER" > target/kernel_test_runner.sh
 	@chmod +x target/kernel_test_runner.sh
@@ -144,10 +143,10 @@ define gen_gdb
     @$(DOCKER_GDB) gdb-multiarch -q kernel_for_jtag
 endef
 
-gdb: clean $(SOURCES)
+gdb:
 	$(call gen_gdb,-C debuginfo=2)
 
-gdb-opt0: clean $(SOURCES)
+gdb-opt0:
 	$(call gen_gdb,-C debuginfo=2 -C opt-level=0)
 
 clippy:
@@ -156,11 +155,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/13_integrated_testing/README.md b/13_integrated_testing/README.md
index 5acc833c..4e157a59 100644
--- a/13_integrated_testing/README.md
+++ b/13_integrated_testing/README.md
@@ -354,7 +354,7 @@ define KERNEL_TEST_RUNNER
 endef
 
 export KERNEL_TEST_RUNNER
-test: $(SOURCES)
+test:
 	@mkdir -p target
 	@echo "$$KERNEL_TEST_RUNNER" > target/kernel_test_runner.sh
 	@chmod +x target/kernel_test_runner.sh
@@ -827,7 +827,7 @@ diff -uNr 12_exceptions_part1_groundwork/Makefile 13_integrated_testing/Makefile
      OPENOCD_ARG       = -f /openocd/tcl/interface/ftdi/olimex-arm-usb-tiny-h.cfg -f /openocd/rpi3.cfg
      JTAG_BOOT_IMAGE   = ../X1_JTAG_boot/jtag_boot_rpi3.img
      LINKER_FILE       = src/bsp/raspberrypi/link.ld
-@@ -28,12 +29,24 @@
+@@ -28,6 +29,7 @@
      QEMU_BINARY       = qemu-system-aarch64
      QEMU_MACHINE_TYPE =
      QEMU_RELEASE_ARGS = -serial stdio -display none
@@ -835,8 +835,9 @@ diff -uNr 12_exceptions_part1_groundwork/Makefile 13_integrated_testing/Makefile
      OPENOCD_ARG       = -f /openocd/tcl/interface/ftdi/olimex-arm-usb-tiny-h.cfg -f /openocd/rpi4.cfg
      JTAG_BOOT_IMAGE   = ../X1_JTAG_boot/jtag_boot_rpi4.img
      LINKER_FILE       = src/bsp/raspberrypi/link.ld
-     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
- endif
+@@ -37,6 +39,17 @@
+ # Export for build.rs
+ export LINKER_FILE
 
 +# Testing-specific arguments
 +ifdef TEST
@@ -849,10 +850,10 @@ diff -uNr 12_exceptions_part1_groundwork/Makefile 13_integrated_testing/Makefile
 +
 +QEMU_MISSING_STRING = "This board is not yet supported for QEMU."
 +
- SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
-
  RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
-@@ -46,6 +59,7 @@
+ RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
+
+@@ -47,6 +60,7 @@
  RUSTC_CMD   = cargo rustc $(COMPILER_ARGS)
  DOC_CMD     = cargo doc $(COMPILER_ARGS)
  CLIPPY_CMD  = cargo clippy $(COMPILER_ARGS)
@@ -860,7 +861,7 @@ diff -uNr 12_exceptions_part1_groundwork/Makefile 13_integrated_testing/Makefile
  OBJCOPY_CMD = rust-objcopy \
      --strip-all            \
      -O binary
-@@ -53,18 +67,20 @@
+@@ -54,18 +68,20 @@
  KERNEL_ELF = target/$(TARGET)/release/kernel
 
  DOCKER_IMAGE         = rustembedded/osdev-utils
@@ -885,16 +886,16 @@ diff -uNr 12_exceptions_part1_groundwork/Makefile 13_integrated_testing/Makefile
 
      DOCKER_CHAINBOOT = $(DOCKER_CMD_DEV) $(DOCKER_ARG_DIR_UTILS) $(DOCKER_IMAGE)
      DOCKER_JTAGBOOT  = $(DOCKER_CMD_DEV) $(DOCKER_ARG_DIR_UTILS) $(DOCKER_ARG_DIR_JTAG) $(DOCKER_IMAGE)
-@@ -76,7 +92,7 @@
+@@ -77,7 +93,7 @@
  EXEC_QEMU     = $(QEMU_BINARY) -M $(QEMU_MACHINE_TYPE)
  EXEC_MINIPUSH = ruby ../utils/minipush.rb
 
 -.PHONY: all doc qemu chainboot jtagboot openocd gdb gdb-opt0 clippy clean readelf objdump nm
 +.PHONY: all doc qemu chainboot jtagboot openocd gdb gdb-opt0 clippy clean readelf objdump nm test
 
- all: clean $(OUTPUT)
-
-@@ -91,11 +107,26 @@
+ all:
+ 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
+@@ -90,11 +106,26 @@
  	$(DOC_CMD) --document-private-items --open
 
  ifeq ($(QEMU_MACHINE_TYPE),)
@@ -915,7 +916,7 @@ diff -uNr 12_exceptions_part1_groundwork/Makefile 13_integrated_testing/Makefile
 +endef
 +
 +export KERNEL_TEST_RUNNER
-+test: $(SOURCES)
++test:
 +	@mkdir -p target
 +	@echo "$$KERNEL_TEST_RUNNER" > target/kernel_test_runner.sh
 +	@chmod +x target/kernel_test_runner.sh
diff --git a/13_integrated_testing/build.rs b/13_integrated_testing/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/13_integrated_testing/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/14_exceptions_part2_peripheral_IRQs/Makefile b/14_exceptions_part2_peripheral_IRQs/Makefile
index 49930b0d..7f6d75c7 100644
--- a/14_exceptions_part2_peripheral_IRQs/Makefile
+++ b/14_exceptions_part2_peripheral_IRQs/Makefile
@@ -36,6 +36,9 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
+# Export for build.rs
+export LINKER_FILE
+
 # Testing-specific arguments
 ifdef TEST
     ifeq ($(TEST),unit)
@@ -47,8 +50,6 @@ endif
 
 QEMU_MISSING_STRING = "This board is not yet supported for QEMU."
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
-
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
 
@@ -95,14 +96,12 @@ EXEC_MINIPUSH = ruby ../utils/minipush.rb
 
 .PHONY: all doc qemu chainboot jtagboot openocd gdb gdb-opt0 clippy clean readelf objdump nm test
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -125,7 +124,7 @@ endef
 
 export KERNEL_TEST_RUNNER
 test: FEATURES += --features qemu-quirks
-test: $(SOURCES)
+test:
 	@mkdir -p target
 	@echo "$$KERNEL_TEST_RUNNER" > target/kernel_test_runner.sh
 	@chmod +x target/kernel_test_runner.sh
@@ -147,10 +146,10 @@ define gen_gdb
     @$(DOCKER_GDB) gdb-multiarch -q kernel_for_jtag
 endef
 
-gdb: clean $(SOURCES)
+gdb:
 	$(call gen_gdb,-C debuginfo=2)
 
-gdb-opt0: clean $(SOURCES)
+gdb-opt0:
 	$(call gen_gdb,-C debuginfo=2 -C opt-level=0)
 
 clippy:
@@ -159,11 +158,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/14_exceptions_part2_peripheral_IRQs/README.md b/14_exceptions_part2_peripheral_IRQs/README.md
index 58a042f5..11af3c58 100644
--- a/14_exceptions_part2_peripheral_IRQs/README.md
+++ b/14_exceptions_part2_peripheral_IRQs/README.md
@@ -762,7 +762,7 @@ diff -uNr 13_integrated_testing/Cargo.toml 14_exceptions_part2_peripheral_IRQs/C
 diff -uNr 13_integrated_testing/Makefile 14_exceptions_part2_peripheral_IRQs/Makefile
 --- 13_integrated_testing/Makefile
 +++ 14_exceptions_part2_peripheral_IRQs/Makefile
-@@ -52,8 +52,9 @@
+@@ -53,8 +53,9 @@
  RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
  RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
 
@@ -773,7 +773,7 @@ diff -uNr 13_integrated_testing/Makefile 14_exceptions_part2_peripheral_IRQs/Mak
      --release
 
  RUSTC_CMD   = cargo rustc $(COMPILER_ARGS)
-@@ -106,6 +107,7 @@
+@@ -105,6 +106,7 @@
  doc:
  	$(DOC_CMD) --document-private-items --open
 
@@ -781,12 +781,12 @@ diff -uNr 13_integrated_testing/Makefile 14_exceptions_part2_peripheral_IRQs/Mak
  ifeq ($(QEMU_MACHINE_TYPE),)
  qemu test:
  	@echo $(QEMU_MISSING_STRING)
-@@ -122,6 +124,7 @@
+@@ -121,6 +123,7 @@
  endef
 
  export KERNEL_TEST_RUNNER
 +test: FEATURES += --features qemu-quirks
- test: $(SOURCES)
+ test:
  	@mkdir -p target
  	@echo "$$KERNEL_TEST_RUNNER" > target/kernel_test_runner.sh
 
diff --git a/14_exceptions_part2_peripheral_IRQs/build.rs b/14_exceptions_part2_peripheral_IRQs/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/14_exceptions_part2_peripheral_IRQs/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/14_exceptions_part2_peripheral_IRQs/kernel b/14_exceptions_part2_peripheral_IRQs/kernel
index de22d5dd..f9e18b29 100755
Binary files a/14_exceptions_part2_peripheral_IRQs/kernel and b/14_exceptions_part2_peripheral_IRQs/kernel differ
diff --git a/14_exceptions_part2_peripheral_IRQs/kernel8.img b/14_exceptions_part2_peripheral_IRQs/kernel8.img
index 51af80c1..a391b5a4 100755
Binary files a/14_exceptions_part2_peripheral_IRQs/kernel8.img and b/14_exceptions_part2_peripheral_IRQs/kernel8.img differ
diff --git a/X1_JTAG_boot/Makefile b/X1_JTAG_boot/Makefile
index 4b18773a..a765953e 100644
--- a/X1_JTAG_boot/Makefile
+++ b/X1_JTAG_boot/Makefile
@@ -30,7 +30,8 @@ else ifeq ($(BSP),rpi4)
     RUSTC_MISC_ARGS   = -C target-cpu=cortex-a72
 endif
 
-SOURCES = $(shell find . -name '*.rs' -o -name '*.S' -o -name '*.ld')
+# Export for build.rs
+export LINKER_FILE
 
 RUSTFLAGS          = -C link-arg=-T$(LINKER_FILE) $(RUSTC_MISC_ARGS)
 RUSTFLAGS_PEDANTIC = $(RUSTFLAGS) -D warnings -D missing_docs
@@ -67,14 +68,12 @@ EXEC_MINIPUSH = ruby ../utils/minipush.rb
 
 .PHONY: all doc qemu chainboot clippy clean readelf objdump nm
 
-all: clean $(OUTPUT)
-
-$(KERNEL_ELF): $(SOURCES)
+all:
 	RUSTFLAGS="$(RUSTFLAGS_PEDANTIC)" $(RUSTC_CMD)
-
-$(OUTPUT): $(KERNEL_ELF)
-	cp $< .
-	$(OBJCOPY_CMD) $< $(OUTPUT)
+	@if [ ! -f kernel ] || [ $(KERNEL_ELF) -nt kernel ]; then \
+	    cp $(KERNEL_ELF) .;                                   \
+	    $(OBJCOPY_CMD) kernel $(OUTPUT);                      \
+	fi
 
 doc:
 	$(DOC_CMD) --document-private-items --open
@@ -96,11 +95,11 @@ clippy:
 clean:
 	rm -rf target
 
-readelf:
+readelf: all
 	readelf -a $(KERNEL_ELF)
 
-objdump:
+objdump: all
 	rust-objdump --arch-name aarch64 -disassemble -no-show-raw-insn -print-imm-hex $(KERNEL_ELF)
 
-nm:
+nm: all
 	rust-nm --demangle --print-size $(KERNEL_ELF) | sort
diff --git a/X1_JTAG_boot/build.rs b/X1_JTAG_boot/build.rs
new file mode 100644
index 00000000..40ee0284
--- /dev/null
+++ b/X1_JTAG_boot/build.rs
@@ -0,0 +1,7 @@
+use std::env;
+
+fn main() {
+    let linker_file = env::var("LINKER_FILE").unwrap();
+
+    println!("cargo:rerun-if-changed={}", linker_file);
+}
diff --git a/utils/devtool.rb b/utils/devtool.rb
index e558f11f..83ec5243 100755
--- a/utils/devtool.rb
+++ b/utils/devtool.rb
@@ -239,6 +239,7 @@ class DevTool
 
         files = tracked_files.select do |f|
             next unless File.exist?(f)
+            next if f.include?('build.rs')
 
             f.include?('Makefile') ||
                 f.include?('Dockerfile') ||