diff --git a/asm.h b/asm.h
index 68210d7..b8a7353 100644
--- a/asm.h
+++ b/asm.h
@@ -14,8 +14,5 @@
                 (0xC0 | (((lim) >> 28) & 0xf)), (((base) >> 24) & 0xff)
 
 #define STA_X     0x8       // Executable segment
-#define STA_E     0x4       // Expand down (non-executable segments)
-#define STA_C     0x4       // Conforming code segment (executable only)
 #define STA_W     0x2       // Writeable (non-executable segments)
 #define STA_R     0x2       // Readable (executable segments)
-#define STA_A     0x1       // Accessed
diff --git a/mmu.h b/mmu.h
index 7b63db0..9d6673c 100644
--- a/mmu.h
+++ b/mmu.h
@@ -2,39 +2,11 @@
 // x86 memory management unit (MMU).
 
 // Eflags register
-#define FL_CF           0x00000001      // Carry Flag
-#define FL_PF           0x00000004      // Parity Flag
-#define FL_AF           0x00000010      // Auxiliary carry Flag
-#define FL_ZF           0x00000040      // Zero Flag
-#define FL_SF           0x00000080      // Sign Flag
-#define FL_TF           0x00000100      // Trap Flag
 #define FL_IF           0x00000200      // Interrupt Enable
-#define FL_DF           0x00000400      // Direction Flag
-#define FL_OF           0x00000800      // Overflow Flag
-#define FL_IOPL_MASK    0x00003000      // I/O Privilege Level bitmask
-#define FL_IOPL_0       0x00000000      //   IOPL == 0
-#define FL_IOPL_1       0x00001000      //   IOPL == 1
-#define FL_IOPL_2       0x00002000      //   IOPL == 2
-#define FL_IOPL_3       0x00003000      //   IOPL == 3
-#define FL_NT           0x00004000      // Nested Task
-#define FL_RF           0x00010000      // Resume Flag
-#define FL_VM           0x00020000      // Virtual 8086 mode
-#define FL_AC           0x00040000      // Alignment Check
-#define FL_VIF          0x00080000      // Virtual Interrupt Flag
-#define FL_VIP          0x00100000      // Virtual Interrupt Pending
-#define FL_ID           0x00200000      // ID flag
 
 // Control Register flags
 #define CR0_PE          0x00000001      // Protection Enable
-#define CR0_MP          0x00000002      // Monitor coProcessor
-#define CR0_EM          0x00000004      // Emulation
-#define CR0_TS          0x00000008      // Task Switched
-#define CR0_ET          0x00000010      // Extension Type
-#define CR0_NE          0x00000020      // Numeric Errror
 #define CR0_WP          0x00010000      // Write Protect
-#define CR0_AM          0x00040000      // Alignment Mask
-#define CR0_NW          0x20000000      // Not Writethrough
-#define CR0_CD          0x40000000      // Cache Disable
 #define CR0_PG          0x80000000      // Paging
 
 #define CR4_PSE         0x00000010      // Page size extension
@@ -82,23 +54,11 @@ struct segdesc {
 
 // Application segment type bits
 #define STA_X       0x8     // Executable segment
-#define STA_E       0x4     // Expand down (non-executable segments)
-#define STA_C       0x4     // Conforming code segment (executable only)
 #define STA_W       0x2     // Writeable (non-executable segments)
 #define STA_R       0x2     // Readable (executable segments)
-#define STA_A       0x1     // Accessed
 
 // System segment type bits
-#define STS_T16A    0x1     // Available 16-bit TSS
-#define STS_LDT     0x2     // Local Descriptor Table
-#define STS_T16B    0x3     // Busy 16-bit TSS
-#define STS_CG16    0x4     // 16-bit Call Gate
-#define STS_TG      0x5     // Task Gate / Coum Transmitions
-#define STS_IG16    0x6     // 16-bit Interrupt Gate
-#define STS_TG16    0x7     // 16-bit Trap Gate
 #define STS_T32A    0x9     // Available 32-bit TSS
-#define STS_T32B    0xB     // Busy 32-bit TSS
-#define STS_CG32    0xC     // 32-bit Call Gate
 #define STS_IG32    0xE     // 32-bit Interrupt Gate
 #define STS_TG32    0xF     // 32-bit Trap Gate
 
@@ -124,7 +84,6 @@ struct segdesc {
 #define NPTENTRIES      1024    // # PTEs per page table
 #define PGSIZE          4096    // bytes mapped by a page
 
-#define PGSHIFT         12      // log2(PGSIZE)
 #define PTXSHIFT        12      // offset of PTX in a linear address
 #define PDXSHIFT        22      // offset of PDX in a linear address
 
@@ -135,12 +94,7 @@ struct segdesc {
 #define PTE_P           0x001   // Present
 #define PTE_W           0x002   // Writeable
 #define PTE_U           0x004   // User
-#define PTE_PWT         0x008   // Write-Through
-#define PTE_PCD         0x010   // Cache-Disable
-#define PTE_A           0x020   // Accessed
-#define PTE_D           0x040   // Dirty
 #define PTE_PS          0x080   // Page Size
-#define PTE_MBZ         0x180   // Bits must be zero
 
 // Address in page table or page directory entry
 #define PTE_ADDR(pte)   ((uint)(pte) & ~0xFFF)
@@ -197,7 +151,7 @@ struct gatedesc {
   uint cs : 16;         // code segment selector
   uint args : 5;        // # args, 0 for interrupt/trap gates
   uint rsv1 : 3;        // reserved(should be zero I guess)
-  uint type : 4;        // type(STS_{TG,IG32,TG32})
+  uint type : 4;        // type(STS_{IG32,TG32})
   uint s : 1;           // must be 0 (system)
   uint dpl : 2;         // descriptor(meaning new) privilege level
   uint p : 1;           // Present
@@ -226,3 +180,6 @@ struct gatedesc {
 }
 
 #endif
+
+//PAGEBREAK!
+// Blank page.