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author | rsc <rsc> | 2006-07-16 16:55:52 +0000 |
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committer | rsc <rsc> | 2006-07-16 16:55:52 +0000 |
commit | 564f787e916392af7b1960d079abf110234305d4 (patch) | |
tree | ad3095388d6723fdb177303a25de38477571c33b /mmu.h | |
parent | 6e6a1dd7d717246f58bc3bbdf2a32e7e3f901cf3 (diff) | |
download | xv6-labs-564f787e916392af7b1960d079abf110234305d4.tar.gz xv6-labs-564f787e916392af7b1960d079abf110234305d4.tar.bz2 xv6-labs-564f787e916392af7b1960d079abf110234305d4.zip |
Eliminate annoying Pseudodesc structure.
Eliminate unnecessary parts of mmu.h.
Diffstat (limited to 'mmu.h')
-rw-r--r-- | mmu.h | 100 |
1 files changed, 3 insertions, 97 deletions
@@ -5,95 +5,10 @@ */ /* - * - * Part 1. Paging data structures and constants. - * + * Register flags and fundamental constants. */ -// A linear address 'la' has a three-part structure as follows: -// -// +--------10------+-------10-------+---------12----------+ -// | Page Directory | Page Table | Offset within Page | -// | Index | Index | | -// +----------------+----------------+---------------------+ -// \--- PDX(la) --/ \--- PTX(la) --/ \---- PGOFF(la) ----/ -// \----------- PPN(la) -----------/ -// -// The PDX, PTX, PGOFF, and PPN macros decompose linear addresses as shown. -// To construct a linear address la from PDX(la), PTX(la), and PGOFF(la), -// use PGADDR(PDX(la), PTX(la), PGOFF(la)). - -// page number field of address -#define PPN(la) (((uintptr_t) (la)) >> PTXSHIFT) -#define VPN(la) PPN(la) // used to index into vpt[] - -// page directory index -#define PDX(la) ((((uintptr_t) (la)) >> PDXSHIFT) & 0x3FF) -#define VPD(la) PDX(la) // used to index into vpd[] - -// page table index -#define PTX(la) ((((uintptr_t) (la)) >> PTXSHIFT) & 0x3FF) - -// offset in page -#define PGOFF(la) (((uintptr_t) (la)) & 0xFFF) - -// construct linear address from indexes and offset -#define PGADDR(d, t, o) ((void*) ((d) << PDXSHIFT | (t) << PTXSHIFT | (o))) - -// Page directory and page table constants. -#define NPDENTRIES 1024 // page directory entries per page directory -#define NPTENTRIES 1024 // page table entries per page table - #define PGSIZE 4096 // bytes mapped by a page -#define PGSHIFT 12 // log2(PGSIZE) - -#define PTSIZE (PGSIZE*NPTENTRIES) // bytes mapped by a page directory entry -#define PTSHIFT 22 // log2(PTSIZE) - -#define PTXSHIFT 12 // offset of PTX in a linear address -#define PDXSHIFT 22 // offset of PDX in a linear address - -// Page table/directory entry flags. -#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 - -// The PTE_AVAIL bits aren't used by the kernel or interpreted by the -// hardware, so user processes are allowed to set them arbitrarily. -#define PTE_AVAIL 0xE00 // Available for software use - -// Only flags in PTE_USER may be used in system calls. -#define PTE_USER (PTE_AVAIL | PTE_P | PTE_W | PTE_U) - -// address in page table entry -#define PTE_ADDR(pte) ((physaddr_t) (pte) & ~0xFFF) - -// 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_PCE 0x00000100 // Performance counter enable -#define CR4_MCE 0x00000040 // Machine Check Enable -#define CR4_PSE 0x00000010 // Page Size Extensions -#define CR4_DE 0x00000008 // Debugging Extensions -#define CR4_TSD 0x00000004 // Time Stamp Disable -#define CR4_PVI 0x00000002 // Protected-Mode Virtual Interrupts -#define CR4_VME 0x00000001 // V86 Mode Extensions // Eflags register #define FL_CF 0x00000001 // Carry Flag @@ -123,10 +38,9 @@ #define FEC_WR 0x2 // Page fault caused by a write #define FEC_U 0x4 // Page fault occured while in user mode - /* * - * Part 2. Segmentation data structures and constants. + * Segmentation data structures and constants. * */ @@ -202,7 +116,7 @@ struct Segdesc { /* * - * Part 3. Traps. + * Traps. * */ @@ -296,13 +210,5 @@ struct Gatedesc { (gate).off_31_16 = (uint32_t) (off) >> 16; \ } -// Pseudo-descriptors used for LGDT, LLDT and LIDT instructions. -struct Pseudodesc { - uint16_t _garbage; // LGDT supposed to be from address 4N+2 - uint16_t lim; // Limit - uint32_t base __attribute__ ((packed)); // Base address -}; -#define PD_ADDR(desc) (&(desc).pd_lim) - #endif /* !__ASSEMBLER__ */ |