10cfc7290Srsc // This file contains definitions for the 20cfc7290Srsc // x86 memory management unit (MMU). 355e95b16Srtm 455e95b16Srtm // Eflags register 555e95b16Srtm #define FL_CF 0x00000001 // Carry Flag 655e95b16Srtm #define FL_PF 0x00000004 // Parity Flag 755e95b16Srtm #define FL_AF 0x00000010 // Auxiliary carry Flag 855e95b16Srtm #define FL_ZF 0x00000040 // Zero Flag 955e95b16Srtm #define FL_SF 0x00000080 // Sign Flag 1055e95b16Srtm #define FL_TF 0x00000100 // Trap Flag 113c821bf9Srsc #define FL_IF 0x00000200 // Interrupt Enable 1255e95b16Srtm #define FL_DF 0x00000400 // Direction Flag 1355e95b16Srtm #define FL_OF 0x00000800 // Overflow Flag 1455e95b16Srtm #define FL_IOPL_MASK 0x00003000 // I/O Privilege Level bitmask 1555e95b16Srtm #define FL_IOPL_0 0x00000000 // IOPL == 0 1655e95b16Srtm #define FL_IOPL_1 0x00001000 // IOPL == 1 1755e95b16Srtm #define FL_IOPL_2 0x00002000 // IOPL == 2 1855e95b16Srtm #define FL_IOPL_3 0x00003000 // IOPL == 3 1955e95b16Srtm #define FL_NT 0x00004000 // Nested Task 2055e95b16Srtm #define FL_RF 0x00010000 // Resume Flag 2155e95b16Srtm #define FL_VM 0x00020000 // Virtual 8086 mode 2255e95b16Srtm #define FL_AC 0x00040000 // Alignment Check 2355e95b16Srtm #define FL_VIF 0x00080000 // Virtual Interrupt Flag 2455e95b16Srtm #define FL_VIP 0x00100000 // Virtual Interrupt Pending 2555e95b16Srtm #define FL_ID 0x00200000 // ID flag 2655e95b16Srtm 277914ab72SAustin Clements // Control Register flags 287914ab72SAustin Clements #define CR0_PE 0x00000001 // Protection Enable 297914ab72SAustin Clements #define CR0_MP 0x00000002 // Monitor coProcessor 307914ab72SAustin Clements #define CR0_EM 0x00000004 // Emulation 317914ab72SAustin Clements #define CR0_TS 0x00000008 // Task Switched 327914ab72SAustin Clements #define CR0_ET 0x00000010 // Extension Type 337914ab72SAustin Clements #define CR0_NE 0x00000020 // Numeric Errror 347914ab72SAustin Clements #define CR0_WP 0x00010000 // Write Protect 357914ab72SAustin Clements #define CR0_AM 0x00040000 // Alignment Mask 367914ab72SAustin Clements #define CR0_NW 0x20000000 // Not Writethrough 377914ab72SAustin Clements #define CR0_CD 0x40000000 // Cache Disable 387914ab72SAustin Clements #define CR0_PG 0x80000000 // Paging 397914ab72SAustin Clements 4094496468SFrans Kaashoek #define CR4_PSE 0x00000010 // Page size extension 4194496468SFrans Kaashoek 42*858475e4SRobert Morris // various segment selectors. 43a56c8d60SFrans Kaashoek #define SEG_KCODE 1 // kernel code 44a56c8d60SFrans Kaashoek #define SEG_KDATA 2 // kernel data+stack 45a56c8d60SFrans Kaashoek #define SEG_KCPU 3 // kernel per-cpu data 46a56c8d60SFrans Kaashoek #define SEG_UCODE 4 // user code 47a56c8d60SFrans Kaashoek #define SEG_UDATA 5 // user data+stack 48a56c8d60SFrans Kaashoek #define SEG_TSS 6 // this process's task state 49a56c8d60SFrans Kaashoek 50*858475e4SRobert Morris // cpu->gdt[NSEGS] holds the above segments. 51*858475e4SRobert Morris #define NSEGS 7 52*858475e4SRobert Morris 537914ab72SAustin Clements //PAGEBREAK! 54a56c8d60SFrans Kaashoek #ifndef __ASSEMBLER__ 55dfcc5b99Srtm // Segment Descriptor 56b5f17007Srsc struct segdesc { 57b5ee5165Srsc uint lim_15_0 : 16; // Low bits of segment limit 58b5ee5165Srsc uint base_15_0 : 16; // Low bits of segment base address 59b5ee5165Srsc uint base_23_16 : 8; // Middle bits of segment base address 60b5ee5165Srsc uint type : 4; // Segment type (see STS_ constants) 61b5ee5165Srsc uint s : 1; // 0 = system, 1 = application 62b5ee5165Srsc uint dpl : 2; // Descriptor Privilege Level 63b5ee5165Srsc uint p : 1; // Present 64b5ee5165Srsc uint lim_19_16 : 4; // High bits of segment limit 65b5ee5165Srsc uint avl : 1; // Unused (available for software use) 66b5ee5165Srsc uint rsv1 : 1; // Reserved 67b5ee5165Srsc uint db : 1; // 0 = 16-bit segment, 1 = 32-bit segment 68b5ee5165Srsc uint g : 1; // Granularity: limit scaled by 4K when set 69b5ee5165Srsc uint base_31_24 : 8; // High bits of segment base address 7055e95b16Srtm }; 71dfcc5b99Srtm 7255e95b16Srtm // Normal segment 73b5f17007Srsc #define SEG(type, base, lim, dpl) (struct segdesc) \ 7448755214SRuss Cox { ((lim) >> 12) & 0xffff, (uint)(base) & 0xffff, \ 7548755214SRuss Cox ((uint)(base) >> 16) & 0xff, type, 1, dpl, 1, \ 7648755214SRuss Cox (uint)(lim) >> 28, 0, 0, 1, 1, (uint)(base) >> 24 } 77b5f17007Srsc #define SEG16(type, base, lim, dpl) (struct segdesc) \ 7848755214SRuss Cox { (lim) & 0xffff, (uint)(base) & 0xffff, \ 7948755214SRuss Cox ((uint)(base) >> 16) & 0xff, type, 1, dpl, 1, \ 8048755214SRuss Cox (uint)(lim) >> 16, 0, 0, 1, 0, (uint)(base) >> 24 } 81a56c8d60SFrans Kaashoek #endif 8255e95b16Srtm 83b6dc6187Srsc #define DPL_USER 0x3 // User DPL 84b6dc6187Srsc 8555e95b16Srtm // Application segment type bits 8655e95b16Srtm #define STA_X 0x8 // Executable segment 8755e95b16Srtm #define STA_E 0x4 // Expand down (non-executable segments) 8855e95b16Srtm #define STA_C 0x4 // Conforming code segment (executable only) 8955e95b16Srtm #define STA_W 0x2 // Writeable (non-executable segments) 9055e95b16Srtm #define STA_R 0x2 // Readable (executable segments) 9155e95b16Srtm #define STA_A 0x1 // Accessed 9255e95b16Srtm 9355e95b16Srtm // System segment type bits 9455e95b16Srtm #define STS_T16A 0x1 // Available 16-bit TSS 9555e95b16Srtm #define STS_LDT 0x2 // Local Descriptor Table 9655e95b16Srtm #define STS_T16B 0x3 // Busy 16-bit TSS 9755e95b16Srtm #define STS_CG16 0x4 // 16-bit Call Gate 9855e95b16Srtm #define STS_TG 0x5 // Task Gate / Coum Transmitions 9955e95b16Srtm #define STS_IG16 0x6 // 16-bit Interrupt Gate 10055e95b16Srtm #define STS_TG16 0x7 // 16-bit Trap Gate 10155e95b16Srtm #define STS_T32A 0x9 // Available 32-bit TSS 10255e95b16Srtm #define STS_T32B 0xB // Busy 32-bit TSS 10355e95b16Srtm #define STS_CG32 0xC // 32-bit Call Gate 10455e95b16Srtm #define STS_IG32 0xE // 32-bit Interrupt Gate 10555e95b16Srtm #define STS_TG32 0xF // 32-bit Trap Gate 10655e95b16Srtm 107c3dcf479SFrans Kaashoek // A virtual address 'la' has a three-part structure as follows: 10840889627SFrans Kaashoek // 10940889627SFrans Kaashoek // +--------10------+-------10-------+---------12----------+ 11040889627SFrans Kaashoek // | Page Directory | Page Table | Offset within Page | 11140889627SFrans Kaashoek // | Index | Index | | 11240889627SFrans Kaashoek // +----------------+----------------+---------------------+ 113c3dcf479SFrans Kaashoek // \--- PDX(va) --/ \--- PTX(va) --/ 11440889627SFrans Kaashoek 11540889627SFrans Kaashoek // page directory index 116c3dcf479SFrans Kaashoek #define PDX(va) (((uint)(va) >> PDXSHIFT) & 0x3FF) 11740889627SFrans Kaashoek 11840889627SFrans Kaashoek // page table index 119c3dcf479SFrans Kaashoek #define PTX(va) (((uint)(va) >> PTXSHIFT) & 0x3FF) 12040889627SFrans Kaashoek 121c3dcf479SFrans Kaashoek // construct virtual address from indexes and offset 12240889627SFrans Kaashoek #define PGADDR(d, t, o) ((uint)((d) << PDXSHIFT | (t) << PTXSHIFT | (o))) 12340889627SFrans Kaashoek 12440889627SFrans Kaashoek // Page directory and page table constants. 125e25b74caSFrans Kaashoek #define NPDENTRIES 1024 // # directory entries per page directory 126e25b74caSFrans Kaashoek #define NPTENTRIES 1024 // # PTEs per page table 127c3dcf479SFrans Kaashoek #define PGSIZE 4096 // bytes mapped by a page 12840889627SFrans Kaashoek 129c3dcf479SFrans Kaashoek #define PGSHIFT 12 // log2(PGSIZE) 13040889627SFrans Kaashoek #define PTXSHIFT 12 // offset of PTX in a linear address 13140889627SFrans Kaashoek #define PDXSHIFT 22 // offset of PDX in a linear address 13240889627SFrans Kaashoek 133eb18645fSRobert Morris #define PGROUNDUP(sz) (((sz)+PGSIZE-1) & ~(PGSIZE-1)) 134c3dcf479SFrans Kaashoek #define PGROUNDDOWN(a) (((a)) & ~(PGSIZE-1)) 135eb18645fSRobert Morris 13640889627SFrans Kaashoek // Page table/directory entry flags. 13740889627SFrans Kaashoek #define PTE_P 0x001 // Present 13840889627SFrans Kaashoek #define PTE_W 0x002 // Writeable 13940889627SFrans Kaashoek #define PTE_U 0x004 // User 14040889627SFrans Kaashoek #define PTE_PWT 0x008 // Write-Through 14140889627SFrans Kaashoek #define PTE_PCD 0x010 // Cache-Disable 14240889627SFrans Kaashoek #define PTE_A 0x020 // Accessed 14340889627SFrans Kaashoek #define PTE_D 0x040 // Dirty 14440889627SFrans Kaashoek #define PTE_PS 0x080 // Page Size 14540889627SFrans Kaashoek #define PTE_MBZ 0x180 // Bits must be zero 14640889627SFrans Kaashoek 14740889627SFrans Kaashoek // Address in page table or page directory entry 14840889627SFrans Kaashoek #define PTE_ADDR(pte) ((uint)(pte) & ~0xFFF) 149ff278344SStephen Tu #define PTE_FLAGS(pte) ((uint)(pte) & 0xFFF) 15040889627SFrans Kaashoek 151a56c8d60SFrans Kaashoek #ifndef __ASSEMBLER__ 15240889627SFrans Kaashoek typedef uint pte_t; 15340889627SFrans Kaashoek 154dfcc5b99Srtm // Task state segment format 155b5f17007Srsc struct taskstate { 15629270816Srtm uint link; // Old ts selector 15711a9947fSrtm uint esp0; // Stack pointers and segment selectors 15829270816Srtm ushort ss0; // after an increase in privilege level 15929270816Srtm ushort padding1; 16029270816Srtm uint *esp1; 16129270816Srtm ushort ss1; 16229270816Srtm ushort padding2; 16329270816Srtm uint *esp2; 16429270816Srtm ushort ss2; 16529270816Srtm ushort padding3; 16629270816Srtm void *cr3; // Page directory base 16729270816Srtm uint *eip; // Saved state from last task switch 16829270816Srtm uint eflags; 16929270816Srtm uint eax; // More saved state (registers) 17029270816Srtm uint ecx; 17129270816Srtm uint edx; 17229270816Srtm uint ebx; 17329270816Srtm uint *esp; 17429270816Srtm uint *ebp; 17529270816Srtm uint esi; 17629270816Srtm uint edi; 17729270816Srtm ushort es; // Even more saved state (segment selectors) 17829270816Srtm ushort padding4; 17929270816Srtm ushort cs; 18029270816Srtm ushort padding5; 18129270816Srtm ushort ss; 18229270816Srtm ushort padding6; 18329270816Srtm ushort ds; 18429270816Srtm ushort padding7; 18529270816Srtm ushort fs; 18629270816Srtm ushort padding8; 18729270816Srtm ushort gs; 18829270816Srtm ushort padding9; 18929270816Srtm ushort ldt; 19029270816Srtm ushort padding10; 19129270816Srtm ushort t; // Trap on task switch 19229270816Srtm ushort iomb; // I/O map base address 19355e95b16Srtm }; 19455e95b16Srtm 195cce27ba9Srsc // PAGEBREAK: 12 19655e95b16Srtm // Gate descriptors for interrupts and traps 197b5f17007Srsc struct gatedesc { 198b5ee5165Srsc uint off_15_0 : 16; // low 16 bits of offset in segment 1990fe118f3Srsc uint cs : 16; // code segment selector 200b5ee5165Srsc uint args : 5; // # args, 0 for interrupt/trap gates 201b5ee5165Srsc uint rsv1 : 3; // reserved(should be zero I guess) 202b5ee5165Srsc uint type : 4; // type(STS_{TG,IG32,TG32}) 203b5ee5165Srsc uint s : 1; // must be 0 (system) 204b5ee5165Srsc uint dpl : 2; // descriptor(meaning new) privilege level 205b5ee5165Srsc uint p : 1; // Present 206b5ee5165Srsc uint off_31_16 : 16; // high bits of offset in segment 20755e95b16Srtm }; 20855e95b16Srtm 20955e95b16Srtm // Set up a normal interrupt/trap gate descriptor. 21055e95b16Srtm // - istrap: 1 for a trap (= exception) gate, 0 for an interrupt gate. 2115be0039cSrtm // interrupt gate clears FL_IF, trap gate leaves FL_IF alone 21255e95b16Srtm // - sel: Code segment selector for interrupt/trap handler 21355e95b16Srtm // - off: Offset in code segment for interrupt/trap handler 21455e95b16Srtm // - dpl: Descriptor Privilege Level - 21555e95b16Srtm // the privilege level required for software to invoke 21655e95b16Srtm // this interrupt/trap gate explicitly using an int instruction. 217ef2bd07aSrsc #define SETGATE(gate, istrap, sel, off, d) \ 21855e95b16Srtm { \ 21929270816Srtm (gate).off_15_0 = (uint)(off) & 0xffff; \ 2200fe118f3Srsc (gate).cs = (sel); \ 221ef2bd07aSrsc (gate).args = 0; \ 222ef2bd07aSrsc (gate).rsv1 = 0; \ 223ef2bd07aSrsc (gate).type = (istrap) ? STS_TG32 : STS_IG32; \ 224ef2bd07aSrsc (gate).s = 0; \ 225ef2bd07aSrsc (gate).dpl = (d); \ 226ef2bd07aSrsc (gate).p = 1; \ 22729270816Srtm (gate).off_31_16 = (uint)(off) >> 16; \ 22855e95b16Srtm } 22955e95b16Srtm 230a56c8d60SFrans Kaashoek #endif 231