diff --git a/include/kernel/idt.h b/include/kernel/idt.h
index 62263dc..7b00530 100644
--- a/include/kernel/idt.h
+++ b/include/kernel/idt.h
@@ -9,6 +9,7 @@ typedef struct IdtDescriptor_t IdtDescriptor_t;
 typedef struct IdtEntry_t IdtEntry_t;
 typedef struct IdtPtr_t IdtPtr_t;
 typedef struct IRQList_t IRQList_t;
+typedef struct ISRFrame_t ISRFrame_t;
 
 // -------------------------------------------------------------------------- //
 
@@ -49,6 +50,27 @@ struct IRQList_t
     } entry[224];
 };
 
+struct ISRFrame_t {
+/* the register file */
+  uint64_t regs[15];
+
+  /* the error code and interrupt id */
+  uint64_t id;
+  uint64_t error;
+
+  /* these are pushed automatically by the CPU */
+  uint64_t rip;
+  uint64_t cs;
+  uint64_t rflags;
+  uint64_t rsp;
+  uint64_t ss;
+} __attribute__((__packed__));
+
+typedef struct
+{
+
+} __attribute__((__packed__)) cpu_state_t;
+
 static char *IsrExceptions[32] = {
     "Divide Error Fault",
     "Debug Exception Trap",
@@ -59,7 +81,7 @@ static char *IsrExceptions[32] = {
     "Invalid Opcode Fault",
     "Device Not Available or No Math Coprocessor Fault",
     "Double Fault Abort",
-    "Coprocessor Segment Overrun Fault",
+    "Coprocessor Segment Overrun Fault (Legacy)",
     "Invalid TSS Fault",
     "Segment Not Present Fault",
     "Stack Segment fault",
@@ -80,7 +102,7 @@ static char *IsrExceptions[32] = {
     "Intel Reserved",
     "Intel Reserved",
     "Intel Reserved",
-    "Intel Reserved",
+    "Security Exception",
     "Intel Reserved"
 };
 
diff --git a/kaleid/kernel/cpu/isr.asm b/kaleid/kernel/cpu/isr.asm
index ba4028f..59247f9 100644
--- a/kaleid/kernel/cpu/isr.asm
+++ b/kaleid/kernel/cpu/isr.asm
@@ -53,26 +53,41 @@ divideByZero:
 ;; ISR handler
 ;;
 isrPreHandler:
-    mov ax, ds
-    push rax
+    pushAll
 
-    mov ax, 0x0
-    mov ds, ax
-    mov es, ax
-    mov fs, ax
-    mov gs, ax
+    ; Check if we are switching from user mode to supervisor mode
+    mov rax, [rsp + 152]
+    and rax, 0x3000
+    jz .SEnter
+
+    swapgs ; XXX need TSS
+
+.SEnter:
+    ; Increment mask count as we configure all interrupts to mask IF
+    ;   automatically in the IDT
+    inc qword [gs:8]
+    ; Call the C routine for dispatching an interrupt
+    cld             ; DF must be cleared by the caller
+    mov rdi, rsp    ; First argument points to the processor state
+    mov rbp, 0      ; Terminate stack traces here
 
     call IdtHandler
 
-    pop rbx
-    mov ds, bx
-    mov es, bx
-    mov fs, bx
-    mov gs, bx
+    ; decrement mask count
+    dec qword [gs:8]
 
+    ; check if we are switching from supervisor to user mode
+    mov rax, [rsp + 152]
+    and rax, 0x3000
+    jz .SExit
+
+    swapgs
+
+.SExit:
     popAll
-    add rsp, 8
-    sti
+    ; pop the error code and interrupt id
+    add rsp, 16
+
     iretq
 
 ;; Divide Error Fault
diff --git a/kaleid/kernel/cpu/isr.inc b/kaleid/kernel/cpu/isr.inc
index 6aad457..be4d109 100644
--- a/kaleid/kernel/cpu/isr.inc
+++ b/kaleid/kernel/cpu/isr.inc
@@ -25,33 +25,47 @@
 [BITS 64]
 
 %macro pushAll 0
-      push   rax
-      push   rcx
-      push   rdx
-      push   rbx
-      push   rbp
-      push   rsi
-      push   rdi
+    push r15
+    push r14
+    push r13
+    push r12
+    push r11
+    push r10
+    push r9
+    push r8
+    push rbp
+    push rdi
+    push rsi
+    push rdx
+    push rcx
+    push rbx
+    push rax
 %endmacro
 
 %macro popAll 0
-      pop      rdi
-      pop      rsi
-      pop      rbp
-      pop      rbx
-      pop      rdx
-      pop      rcx
-      pop      rax
+    pop rax
+    pop rbx
+    pop rcx
+    pop rdx
+    pop rsi
+    pop rdi
+    pop rbp
+    pop r8
+    pop r9
+    pop r10
+    pop r11
+    pop r12
+    pop r13
+    pop r14
+    pop r15
 %endmacro
 
 %macro IsrWithoutErrCode 1
 global isr%1
 isr%1:
     cli
-    push byte 0
-    pushAll
-    xor rdi, rdi
-    mov rdi, %1
+    push 0
+    push %1
     jmp isrPreHandler
 %endmacro
 
@@ -59,8 +73,6 @@ isr%1:
 global isr%1
 isr%1:
     cli
-    pushAll
-    xor rdi, rdi
-    mov rdi, %1
+    push %1
     jmp isrPreHandler
 %endmacro
diff --git a/kaleid/kernel/init/init.c b/kaleid/kernel/init/init.c
index b35bb5b..706f03d 100644
--- a/kaleid/kernel/init/init.c
+++ b/kaleid/kernel/init/init.c
@@ -94,14 +94,12 @@ noreturn void BtStartKern(multiboot_info_t *mbInfo, uint mbMagic, void *codeSeg)
 
     IoPrintRtcTime();
 
-    /* KernLog("There was %d ticks\n", IoGetRtcTicks()); */
-    /* for (uint i = 1; i < 2 ; i++) { */
-    /*     while (IoGetRtcTicks() < i * 10000) { */
-    /*     } */
-    /*     IoPrintRtcTime(); */
-    /* } */
-    int* var = 7*GB;
-    *var = 2;
+    KernLog("There was %d ticks\n", IoGetRtcTicks());
+    for (uint i = 1; i < 20000 ; i++) {
+        while (IoGetRtcTicks() < i * 10000) {
+        }
+        IoPrintRtcTime();
+    }
 
     KernLog("Goodbye after %d ticks\n", IoGetRtcTicks());
     // End this machine's suffering
diff --git a/kaleid/kernel/io/keyb.asm b/kaleid/kernel/io/keyb.asm
index 5128db4..5872003 100644
--- a/kaleid/kernel/io/keyb.asm
+++ b/kaleid/kernel/io/keyb.asm
@@ -65,5 +65,4 @@ KeybIsr:
     mov ds, ax
 
     popAll
-    sti
     iretq
diff --git a/kaleid/kernel/io/rtc.asm b/kaleid/kernel/io/rtc.asm
index 0457ad4..214af07 100644
--- a/kaleid/kernel/io/rtc.asm
+++ b/kaleid/kernel/io/rtc.asm
@@ -65,5 +65,4 @@ RtcIsr:
     mov ds, ax
 
     popAll
-    sti
     iretq