diff --git a/Makefile b/Makefile
index e4bcc76..262a036 100644
--- a/Makefile
+++ b/Makefile
@@ -7,6 +7,8 @@ ifeq ($(ARCH),amd64)
 CFLAGS+=-DARCH_AMD64
 endif
 
+include config
+
 export O?=$(abspath build)
 
 # Include base system
@@ -14,8 +16,7 @@ include sys/conf.mk
 # Arch details
 include sys/$(ARCH)/conf.mk
 
-
-all: mkdirs $(TARGETS)
+all: mkdirs config $(TARGETS)
 
 clean:
 	@rm -rf $(O)
diff --git a/config b/config
new file mode 100644
index 0000000..b832187
--- /dev/null
+++ b/config
@@ -0,0 +1,2 @@
+# vi: ft=make :
+export AMD64_TRACE_IRQ=1
diff --git a/include/sys/amd64/asm/asm_irq.h b/include/sys/amd64/asm/asm_irq.h
index 413c0c8..23dc121 100644
--- a/include/sys/amd64/asm/asm_irq.h
+++ b/include/sys/amd64/asm/asm_irq.h
@@ -2,9 +2,20 @@
 
 #define AMD64_STACK_CTX_CANARY      0xBAD57AC6BAD57AC6
 // TODO: use base + off instead of an absolute address
+#define AMD64_LAPIC_REG_ID_ABS      0xFFFFFF00FEE00020
 #define AMD64_LAPIC_REG_EOI_ABS     0xFFFFFF00FEE000B0
 
 #if defined(__ASM__)
+
+.macro irq_trace, n
+#if defined(AMD64_TRACE_IRQ)
+    // Assuming we're entering from safe context
+    movq $\n, %rdi
+    call amd64_irq_trace
+#else
+#endif
+.endm
+
 .macro irq_push_ctx
     pushq %rax
     pushq %rcx
diff --git a/sys/amd64/conf.mk b/sys/amd64/conf.mk
index 9d07a38..223fb17 100644
--- a/sys/amd64/conf.mk
+++ b/sys/amd64/conf.mk
@@ -5,6 +5,7 @@ include sys/amd64/compiler.mk
 all:
 ### Kernel build
 DEFINES+=-DARCH_AMD64
+
 OBJS+=$(O)/sys/amd64/hw/rs232.o \
 	  $(O)/sys/amd64/kernel.o \
 	  $(O)/sys/amd64/hw/gdt.o \
@@ -17,6 +18,13 @@ OBJS+=$(O)/sys/amd64/hw/rs232.o \
 	  $(O)/sys/amd64/hw/irq0.o \
 	  $(O)/sys/amd64/hw/ap_code_blob.o \
 	  $(O)/sys/amd64/hw/con.o
+
+### From config
+ifdef AMD64_TRACE_IRQ
+DEFINES+=-DAMD64_TRACE_IRQ
+OBJS+=$(O)/sys/amd64/hw/irq_trace.o
+endif
+
 kernel_OBJS=$(O)/sys/amd64/entry.o \
 			$(OBJS)
 kernel_LINKER=sys/amd64/link.ld
@@ -51,23 +59,23 @@ DIRS+=$(O)/sys/amd64/image/boot/grub \
 # add .inc includes for asm
 HEADERS+=$(shell find include -name "*.inc")
 
-$(O)/sys/amd64/kernel.elf: $(kernel_OBJS) $(kernel_LINKER)
+$(O)/sys/amd64/kernel.elf: $(kernel_OBJS) $(kernel_LINKER) config
 	@printf " LD\t%s\n" $(@:$(O)/%=%)
 	@$(CC64) $(kernel_LDFLAGS)  -o $@ $(kernel_OBJS)
 
-$(O)/sys/%.o: sys/%.S $(HEADERS)
+$(O)/sys/%.o: sys/%.S $(HEADERS) config
 	@printf " AS\t%s\n" $(@:$(O)/%=%)
 	@$(CC64) $(kernel_CFLAGS) -D__ASM__ -c -o $@ $<
 
-$(O)/sys/%.o: sys/%.c $(HEADERS)
+$(O)/sys/%.o: sys/%.c $(HEADERS) config
 	@printf " CC\t%s\n" $(@:$(O)/%=%)
 	@$(CC64) $(kernel_CFLAGS) -c -o $@ $<
 
-$(O)/sys/amd64/hw/ap_code_blob.o: $(O)/sys/amd64/hw/ap_code.bin
+$(O)/sys/amd64/hw/ap_code_blob.o: $(O)/sys/amd64/hw/ap_code.bin config
 	@printf " AS\t%s\n" $(@:$(O)/%=%)
 	@$(CC64) $(kernel_CFLAGS) -c -DAP_CODE_BIN='"$<"' -o $@ sys/amd64/hw/ap_code_blob.S
 
-$(O)/sys/amd64/hw/ap_code.bin: sys/amd64/hw/ap_code.nasm
+$(O)/sys/amd64/hw/ap_code.bin: sys/amd64/hw/ap_code.nasm config
 	@printf " NASM\t%s\n" $(@:$(O)/%=%)
 	@nasm -f bin -o $@ $<
 
@@ -90,15 +98,15 @@ loader_CFLAGS=-ffreestanding \
 			  -Wno-language-extension-token
 loader_LDFLAGS=-nostdlib -T$(loader_LINKER)
 
-$(O)/sys/amd64/loader.elf: $(loader_OBJS) $(loader_LINKER)
+$(O)/sys/amd64/loader.elf: $(loader_OBJS) $(loader_LINKER) config
 	@printf " LD\t%s\n" $(@:$(O)/%=%)
 	@$(CC86) $(loader_LDFLAGS) -o $@ $(loader_OBJS)
 
-$(O)/sys/amd64/loader/%.o: sys/amd64/loader/%.S $(HEADERS)
+$(O)/sys/amd64/loader/%.o: sys/amd64/loader/%.S $(HEADERS) config
 	@printf " AS\t%s\n" $(@:$(O)/%=%)
 	@$(CC86) $(loader_CFLAGS) -D__ASM__ -c -o $@ $<
 
-$(O)/sys/amd64/loader/%.o: sys/amd64/loader/%.c $(HEADERS)
+$(O)/sys/amd64/loader/%.o: sys/amd64/loader/%.c $(HEADERS) config
 	@printf " CC\t%s\n" $(@:$(O)/%=%)
 	@$(CC86) $(loader_CFLAGS) -c -o $@ $<
 
diff --git a/sys/amd64/hw/apic.c b/sys/amd64/hw/apic.c
index 6b58022..a5ef0e9 100644
--- a/sys/amd64/hw/apic.c
+++ b/sys/amd64/hw/apic.c
@@ -97,10 +97,23 @@ static void amd64_pic8259_disable(void) {
 
 static void amd64_ap_code_entry(void) {
     // Can do this as core should've bootstrapped BEFORE BSP checks this value again
+    // {{{ CRITICAL BLOCK
     ++started_up_aps;
+    // }}}
+
+    // Enable LAPIC timer
+    kdebug("AP %d startup\n", started_up_aps);
+
+    // Enable LAPIC.SVR.SoftwareEnable bit
+    // And set spurious interrupt mapping to 0xFF
+    *(uint32_t *) (lapic_base + IA32_LAPIC_REG_SVR) |= (1 << 8) | (0xFF);
+
+    *(uint32_t *) (lapic_base + IA32_LAPIC_REG_LVTT) = 32 | 0x20000;
+    *(uint32_t *) (lapic_base + IA32_LAPIC_REG_TMRDIV) = 1;
+    *(uint32_t *) (lapic_base + IA32_LAPIC_REG_TMRINITCNT) = 0xFFFFFFF;
 
     while (1) {
-        asm ("cli; hlt");
+        asm ("sti; hlt");
     }
 }
 
@@ -177,7 +190,7 @@ void amd64_apic_init(struct acpi_madt *madt) {
     amd64_pic8259_disable();
 
     // Determine the BSP LAPIC ID
-    bsp_lapic_id = *(uint32_t *) (lapic_base + IA32_LAPIC_REG_ID);
+    bsp_lapic_id = (*(uint32_t *) (lapic_base + IA32_LAPIC_REG_ID) >> 24);
     kdebug("BSP Local APIC ID: %d\n", bsp_lapic_id);
 
     // Enable LAPIC.SVR.SoftwareEnable bit
@@ -207,6 +220,6 @@ void amd64_apic_init(struct acpi_madt *madt) {
 
     // Enable LAPIC timer
     *(uint32_t *) (lapic_base + IA32_LAPIC_REG_LVTT) = 32 | 0x20000;
-    *(uint32_t *) (lapic_base + IA32_LAPIC_REG_TMRDIV) = 2;
-    *(uint32_t *) (lapic_base + IA32_LAPIC_REG_TMRINITCNT) = 100000;
+    *(uint32_t *) (lapic_base + IA32_LAPIC_REG_TMRDIV) = 1;
+    *(uint32_t *) (lapic_base + IA32_LAPIC_REG_TMRINITCNT) = 0xFFFFFFF;
 }
diff --git a/sys/amd64/hw/irq0.S b/sys/amd64/hw/irq0.S
index 63f968b..5b25788 100644
--- a/sys/amd64/hw/irq0.S
+++ b/sys/amd64/hw/irq0.S
@@ -3,6 +3,7 @@
 
 .global amd64_irq0
 amd64_irq0:
+    cli
     // Interrupt entry:
     // rsp should be one of the following:
     //  The one specified in the TSS.RSP0
@@ -12,6 +13,8 @@ amd64_irq0:
     // Let's adhere to the amd64 ABI
     movq %rsp, %rbp
 
+    irq_trace 0
+
     // TODO: call sched here, do something
 
     // EOI
diff --git a/sys/amd64/hw/irq_trace.S b/sys/amd64/hw/irq_trace.S
new file mode 100644
index 0000000..cb7f259
--- /dev/null
+++ b/sys/amd64/hw/irq_trace.S
@@ -0,0 +1,24 @@
+#include "asm/asm_irq.h"
+
+.section .text
+.global amd64_irq_trace
+amd64_irq_trace:
+    pushq %rbp
+    movq %rsp, %rbp
+
+    // Get LAPIC ID
+    // TODO: support non-APIC configs
+    movq $AMD64_LAPIC_REG_ID_ABS, %rax
+    movl (%rax), %edx
+    shrl $24, %edx
+
+    leaq _irq_msg_fmt(%rip), %rsi
+    movq %rdi, %rcx
+    xorq %rdi, %rdi
+    call debugf
+
+    leaveq
+    retq
+
+_irq_msg_fmt:
+    .string "[IRQ @ %d] %d\n"