diff options
Diffstat (limited to 'mmu.h')
| -rw-r--r-- | mmu.h | 160 |
1 files changed, 0 insertions, 160 deletions
@@ -1,160 +0,0 @@ -// This file contains definitions for the -// x86 memory management unit (MMU). - -// Eflags register -#define FL_TF 0x00000100 // Trap Flag -#define FL_IF 0x00000200 // Interrupt Enable - - -// Control Register flags -#define CR0_PE 0x00000001 // Protection Enable -#define CR0_WP 0x00010000 // Write Protect -#define CR0_PG 0x80000000 // Paging - -#define CR4_PSE 0x00000010 // Page size extension - -// Segment selectors (indexes) in our GDTs. -// Defined by our convention, not the architecture. -#define SEG_KCODE32 (1<<3) // kernel 32-bit code segment -#define SEG_KCODE (2<<3) // kernel code segment -#define SEG_KDATA (3<<3) // kernel data segment -#define SEG_TSS (4<<3) // tss segment - takes two slots -#define SEG_UDATA (6<<3) // user data segment -#define SEG_UCODE (7<<3) // user code segment - -#define NSEGS 8 - -#ifndef __ASSEMBLER__ -struct segdesc { - uint16 limit0; - uint16 base0; - uint8 base1; - uint8 bits; - uint8 bitslimit1; - uint8 base2; -}; - -// SEGDESC constructs a segment descriptor literal -// with the given, base, limit, and type bits. -#define SEGDESC(base, limit, bits) (struct segdesc){ \ - (limit)&0xffff, (base)&0xffff, \ - ((base)>>16)&0xff, \ - (bits)&0xff, \ - (((bits)>>4)&0xf0) | ((limit>>16)&0xf), \ - ((base)>>24)&0xff, \ -} - -// SEGDESCHI constructs an extension segment descriptor -// literal that records the high bits of base. -#define SEGDESCHI(base) (struct segdesc) { \ - (((base)>>32)&0xffff), (((base)>>48)&0xffff), \ -} - -#endif - -#define DPL_USER 0x3 // User DPL - -#define SEG_A (1<<0) // segment accessed bit -#define SEG_R (1<<1) // readable (code) -#define SEG_W (1<<1) // writable (data) -#define SEG_C (1<<2) // conforming segment (code) -#define SEG_E (1<<2) // expand-down bit (data) -#define SEG_CODE (1<<3) // code segment (instead of data) - -// User and system segment bits. -#define SEG_S (1<<4) // if 0, system descriptor -#define SEG_DPL(x) ((x)<<5) // descriptor privilege level (2 bits) -#define SEG_P (1<<7) // segment present -#define SEG_AVL (1<<8) // available for operating system use -#define SEG_L (1<<9) // long mode -#define SEG_D (1<<10) // default operation size 32-bit -#define SEG_G (1<<11) // granularity - -// Application segment type bits -#define STA_X 0x8 // Executable segment -#define STA_W 0x2 // Writeable (non-executable segments) -#define STA_R 0x2 // Readable (executable segments) - -// System segment type bits -#define SEG_LDT (2<<0) // local descriptor table -#define SEG_TSS64A (9<<0) // available 64-bit TSS -#define SEG_TSS64B (11<<0) // busy 64-bit TSS -#define SEG_CALL64 (12<<0) // 64-bit call gate -#define SEG_INTR64 (14<<0) // 64-bit interrupt gate -#define SEG_TRAP64 (15<<0) // 64-bit trap gate - -// A virtual address 'la' has a six-part structure as follows: -// -// +--16--+---9---+------9-------+-----9----+----9-------+----12-------+ -// | Sign | PML4 |Page Directory| Page Dir |Page Table | Offset Page | -// |Extend| Index | Pointer Index| Index | Index | in Page | -// +------+-------+--------------+----------+------------+-------------+ -// L3 pgtab L2 pgtab L1 pgtab L0 pgtab - -// Page directory and page table constants. -#define NPDENTRIES 512 // # directory entries per page directory -#define PGSIZE 4096 // bytes mapped by a page -#define PGSHIFT 12 // offset of PTX in a linear address - -#define PXMASK 0x1FF -#define PXSHIFT(n) (PGSHIFT+(9*(n))) // shift for index into level n page table -#define PX(n, va) ((((uint64) (va)) >> PXSHIFT(n)) & PXMASK) -#define L_PML4 3 - -#define PGROUNDUP(sz) (((sz)+PGSIZE-1) & ~(PGSIZE-1)) -#define PGROUNDDOWN(a) (((a)) & ~(PGSIZE-1)) - -// Page table/directory entry flags. -#define PTE_P 0x001 // Present -#define PTE_W 0x002 // Writeable -#define PTE_U 0x004 // User -#define PTE_PS 0x080 // Page Size -#define PTE_PWT 0x008 // Write-Through -#define PTE_PCD 0x010 // Cache-Disable - -// Address in page table or page directory entry -#define PTE_ADDR(pte) ((uint64)(pte) & ~0xFFF) -#define PTE_FLAGS(pte) ((uint64)(pte) & 0xFFF) - -#ifndef __ASSEMBLER__ - -typedef uint64 pte_t; - -struct taskstate { - uint8 reserved0[4]; - uint64 rsp[3]; - uint64 ist[8]; - uint8 reserved1[10]; - uint16 iomba; - uint8 iopb[0]; -} __attribute__ ((packed)); - -#define INT_P (1<<7) // interrupt descriptor present - -struct intgate -{ - uint16 rip0; - uint16 cs; - uint8 reserved0; - uint8 bits; - uint16 rip1; - uint32 rip2; - uint32 reserved1; -}; - -// INTDESC constructs an interrupt descriptor literal -// that records the given code segment, instruction pointer, -// and type bits. -#define INTDESC(cs, rip, bits) (struct intgate){ \ - (rip)&0xffff, (cs), 0, bits, ((rip)>>16)&0xffff, \ - (uint64)(rip)>>32, 0, \ -} - -// See section 4.6 of amd64 vol2 -struct desctr -{ - uint16 limit; - uint64 base; -} __attribute__((packed, aligned(16))); // important! - -#endif |