diff --git a/include/sys/amd64/hw/gdt.h b/include/sys/amd64/hw/gdt.h
index 00b604b..57451c4 100644
--- a/include/sys/amd64/hw/gdt.h
+++ b/include/sys/amd64/hw/gdt.h
@@ -34,6 +34,6 @@ typedef struct {
     uintptr_t offset;
 } __attribute__((packed)) amd64_gdt_ptr_t;
 
-extern amd64_gdt_ptr_t amd64_gdtr;
+amd64_gdt_ptr_t *amd64_gdtr_get(int cpu);
 
 void amd64_gdt_init(void);
diff --git a/sys/amd64/hw/gdt.c b/sys/amd64/hw/gdt.c
index 978ed1f..1b129aa 100644
--- a/sys/amd64/hw/gdt.c
+++ b/sys/amd64/hw/gdt.c
@@ -3,11 +3,9 @@
 
 extern void amd64_gdt_load(void *p);
 
-static amd64_gdt_entry_t gdt[GDT_SIZE] = { 0 };
-amd64_gdt_ptr_t amd64_gdtr = {
-    sizeof(gdt) - 1,
-    (uintptr_t) gdt
-};
+static amd64_gdt_entry_t gdt[GDT_SIZE * AMD64_MAX_SMP] = { 0 };
+static amd64_gdt_ptr_t amd64_gdtr[AMD64_MAX_SMP];
+static amd64_tss_t amd64_tss[AMD64_MAX_SMP] = { 0 };
 
 #define GDT_ACC_AC      (1 << 0)
 #define GDT_ACC_RW      (1 << 1)
@@ -24,29 +22,38 @@ amd64_gdt_ptr_t amd64_gdtr = {
 #define GDT_FLG_SZ      (1 << 6)
 #define GDT_FLG_GR      (1 << 7)
 
-static void amd64_gdt_set(int idx, uint32_t base, uint32_t limit, uint8_t flags, uint8_t access) {
-    gdt[idx].base_lo = base & 0xFFFF;
-    gdt[idx].base_mi = (base >> 16) & 0xFF;
-    gdt[idx].base_hi = (base >> 24) & 0xFF;
-    gdt[idx].access = access;
-    gdt[idx].flags = (flags & 0xF0) | ((limit >> 16) & 0xF);
-    gdt[idx].limit_lo = limit & 0xFFFF;
+static void amd64_gdt_set(int cpu, int idx, uint32_t base, uint32_t limit, uint8_t flags, uint8_t access) {
+    gdt[idx + cpu * GDT_SIZE].base_lo = base & 0xFFFF;
+    gdt[idx + cpu * GDT_SIZE].base_mi = (base >> 16) & 0xFF;
+    gdt[idx + cpu * GDT_SIZE].base_hi = (base >> 24) & 0xFF;
+    gdt[idx + cpu * GDT_SIZE].access = access;
+    gdt[idx + cpu * GDT_SIZE].flags = (flags & 0xF0) | ((limit >> 16) & 0xF);
+    gdt[idx + cpu * GDT_SIZE].limit_lo = limit & 0xFFFF;
+}
+
+amd64_gdt_ptr_t *amd64_gdtr_get(int cpu) {
+    return &amd64_gdtr[cpu];
 }
 
 void amd64_gdt_init(void) {
-    amd64_gdt_set(0, 0, 0, 0, 0);
-    amd64_gdt_set(1, 0, 0,
-                  GDT_FLG_LONG,
-                  GDT_ACC_PR | GDT_ACC_S | GDT_ACC_EX);
-    amd64_gdt_set(2, 0, 0,
-                  0,
-                  GDT_ACC_PR | GDT_ACC_S | GDT_ACC_RW);
-    amd64_gdt_set(3, 0, 0,
-                  GDT_FLG_LONG,
-                  GDT_ACC_PR | GDT_ACC_R3 | GDT_ACC_S | GDT_ACC_EX);
-    amd64_gdt_set(4, 0, 0,
-                  0,
-                  GDT_ACC_PR | GDT_ACC_R3 | GDT_ACC_S | GDT_ACC_RW);
+    for (size_t i = 0; i < AMD64_MAX_SMP; ++i) {
+        amd64_gdt_set(i, 0, 0, 0, 0, 0);
+        amd64_gdt_set(i, 1, 0, 0,
+                      GDT_FLG_LONG,
+                      GDT_ACC_PR | GDT_ACC_S | GDT_ACC_EX);
+        amd64_gdt_set(i, 2, 0, 0,
+                      0,
+                      GDT_ACC_PR | GDT_ACC_S | GDT_ACC_RW);
+        //amd64_gdt_set(i, 3, 0, 0,
+        //              0,
+        //              GDT_ACC_PR | GDT_ACC_R3 | GDT_ACC_S | GDT_ACC_RW);
+        //amd64_gdt_set(i, 4, 0, 0,
+        //              GDT_FLG_LONG,
+        //              GDT_ACC_PR | GDT_ACC_R3 | GDT_ACC_S | GDT_ACC_EX);
+
+        amd64_gdtr[i].size = sizeof(GDT_SIZE) * sizeof(amd64_gdt_entry_t) - 1;
+        amd64_gdtr[i].offset = (uintptr_t) &gdt[GDT_SIZE * i];
+    }
 
     amd64_gdt_load(&amd64_gdtr);
 }
diff --git a/sys/amd64/smp/smp.c b/sys/amd64/smp/smp.c
index 363eac8..e10efee 100644
--- a/sys/amd64/smp/smp.c
+++ b/sys/amd64/smp/smp.c
@@ -81,12 +81,9 @@ void amd64_load_ap_code(void) {
     struct ap_param_block *appb = (struct ap_param_block *) SMP_AP_BOOTSTRAP_DATA;
     extern mm_space_t mm_kernel;
     uintptr_t mm_kernel_phys = (uintptr_t) mm_kernel - 0xFFFFFF0000000000;
-    uintptr_t amd64_gdtr_phys = (uintptr_t) &amd64_gdtr - 0xFFFFFF0000000000;
 
     // 0x7FC0 - MM_PHYS(mm_kernel)
     appb->cr3 = mm_kernel_phys;
-    // 0x7FC8 - MM_PHYS(amd64_gdtr)
-    appb->gdtr_phys = amd64_gdtr_phys;
     // 0x7FD0 - amd64_idtr
     appb->idtr = (uintptr_t) &amd64_idtr;
     // 0x7FD8 - amd64_core_entry
@@ -96,7 +93,10 @@ void amd64_load_ap_code(void) {
 static void amd64_set_ap_params(uint8_t cpu_no) {
     // Allocate a new AP kernel stack
     uintptr_t stack_ptr = (uintptr_t) kernel_stacks_top - (cpu_no - 1) * 65536;
+    uintptr_t amd64_gdtr_phys = (uintptr_t) amd64_gdtr_get(cpu_no) - 0xFFFFFF0000000000;
     struct ap_param_block *appb = (struct ap_param_block *) SMP_AP_BOOTSTRAP_DATA;
+    // 0x7FC8 - MM_PHYS(amd64_gdtr)
+    appb->gdtr_phys = amd64_gdtr_phys;
     // 0x7FE0 - stack_ptr
     appb->rsp = stack_ptr;
     // 0x7FE8
diff --git a/sys/amd64/sys/sched.c b/sys/amd64/sys/sched.c
index 0c62403..04f5d39 100644
--- a/sys/amd64/sys/sched.c
+++ b/sys/amd64/sys/sched.c
@@ -11,30 +11,35 @@ static spin_t sched_lock = 0;
 #define TEST_STACK  65536
 
 // Testing
-static char t_stack[TEST_STACK * AMD64_MAX_SMP] = {0};
+static char t_stack0[TEST_STACK * AMD64_MAX_SMP] = {0};
+static char t_stack3[TEST_STACK * AMD64_MAX_SMP] = {0};
 static struct thread t_idle[AMD64_MAX_SMP] = {0};
 
 void idle_func(uintptr_t id) {
     while (1) {
-        kdebug("%d\n", id);
-        asm volatile ("sti; hlt");
+        //kdebug("%d\n", id);
+        //asm volatile ("sti; hlt");
     }
 }
 
 static void make_idle_task(int cpu) {
     struct thread *t = &t_idle[cpu];
 
-    uintptr_t stack_base = (uintptr_t) t_stack + cpu * TEST_STACK;
+    uintptr_t stack0_base = (uintptr_t) t_stack0 + cpu * TEST_STACK;
+    uintptr_t stack3_base = (uintptr_t) t_stack3 + cpu * TEST_STACK;
 
-    t->data.stack0_base = stack_base;
+    t->data.stack0_base = stack0_base;
     t->data.stack0_size = TEST_STACK;
-    t->data.rsp0 = stack_base + TEST_STACK - sizeof(struct cpu_context);
+    t->data.rsp0 = stack0_base + TEST_STACK - sizeof(struct cpu_context);
+
+    t->data.stack3_base = stack3_base;
+    t->data.stack3_size = TEST_STACK;
 
     // Setup context
     struct cpu_context *ctx = (struct cpu_context *) t->data.rsp0;
 
     ctx->rip = (uintptr_t) idle_func;
-    ctx->rsp = t->data.rsp0;
+    ctx->rsp = t->data.stack3_base + t->data.stack3_size;
     ctx->cs = 0x08;
     ctx->ss = 0x10;
     ctx->rflags = 0x248;