diff options
author | Michael Shalayeff <mickey@cvs.openbsd.org> | 2001-01-26 23:05:30 +0000 |
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committer | Michael Shalayeff <mickey@cvs.openbsd.org> | 2001-01-26 23:05:30 +0000 |
commit | 970fb4b0003ae82a378bf02f9bac58a330d26885 (patch) | |
tree | 948ed408bd123407498008d76c079fbd1c7e82de /sys/arch/i386 | |
parent | b617010d5ac81cf70ab82d9cae430567245ecf05 (diff) |
define large page frame mask; also remove trailing spaces
Diffstat (limited to 'sys/arch/i386')
-rw-r--r-- | sys/arch/i386/include/pte.h | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/sys/arch/i386/include/pte.h b/sys/arch/i386/include/pte.h index 59f9e91ad35..711716cf5ff 100644 --- a/sys/arch/i386/include/pte.h +++ b/sys/arch/i386/include/pte.h @@ -1,4 +1,4 @@ -/* $OpenBSD: pte.h,v 1.3 2000/03/01 22:48:14 niklas Exp $ */ +/* $OpenBSD: pte.h,v 1.4 2001/01/26 23:05:29 mickey Exp $ */ /* $NetBSD: pte.h,v 1.11 1998/02/06 21:58:05 thorpej Exp $ */ /* @@ -54,8 +54,8 @@ * the first level table (segment table?) is called a "page directory" * and it contains 1024 page directory entries (PDEs). each PDE is * 4 bytes (an int), so a PD fits in a single 4K page. this page is - * the page directory page (PDP). each PDE in a PDP maps 4MB of space - * (1024 * 4MB = 4GB). a PDE contains the physical address of the + * the page directory page (PDP). each PDE in a PDP maps 4MB of space + * (1024 * 4MB = 4GB). a PDE contains the physical address of the * second level table: the page table. or, if 4MB pages are being used, * then the PDE contains the PA of the 4MB page being mapped. * @@ -65,7 +65,7 @@ * each PTE in a PTP maps one 4K page (1024 * 4K = 4MB). a PTE contains * the physical address of the page it maps and some flag bits (described * below). - * + * * the processor has a special register, "cr3", which points to the * the PDP which is currently controlling the mappings of the virtual * address space. @@ -92,7 +92,7 @@ * p h y s i c a l a d d r * * the i386 caches PTEs in a TLB. it is important to flush out old - * TLB mappings when making a change to a mappings. writing to the + * TLB mappings when making a change to a mappings. writing to the * %cr3 will flush the entire TLB. newer processors also have an * instruction that will invalidate the mapping of a single page (which * is useful if you are changing a single mappings because it preserves @@ -105,7 +105,7 @@ * 10 n/a available for OS use, hardware ignores it * 9 n/a available for OS use, hardware ignores it * 8 G global bit (see discussion below) - * 7 PS page size [for PDEs] (0=4k, 1=4M <if supported>) + * 7 PS page size [for PDEs] (0=4k, 1=4M <if supported>) * 6 D dirty (modified) page * 5 A accessed (referenced) page * 4 PCD cache disable @@ -114,16 +114,16 @@ * 1 R/W read/write bit (0=read only, 1=read-write) * 0 P present (valid) * - * notes: + * notes: * - on the i386 the R/W bit is ignored if processor is in supervisor * state (bug!) * - PS is only supported on newer processors - * - PTEs with the G bit are global in the sense that they are not - * flushed from the TLB when %cr3 is written (to flush, use the + * - PTEs with the G bit are global in the sense that they are not + * flushed from the TLB when %cr3 is written (to flush, use the * "flush single page" instruction). this is only supported on * newer processors. this bit can be used to keep the kernel's * TLB entries around while context switching. since the kernel - * is mapped into all processes at the same place it does not make + * is mapped into all processes at the same place it does not make * sense to flush these entries when switching from one process' * pmap to another. */ @@ -176,7 +176,8 @@ typedef u_int32_t pt_entry_t; /* PTE */ #endif #define PG_AVAIL2 0x00000400 /* ignored by hardware */ #define PG_AVAIL3 0x00000800 /* ignored by hardware */ -#define PG_FRAME 0xfffff000 /* page frame mask */ +#define PG_FRAME 0xfffff000 /* page frame mask */ +#define PG_LGFRAME 0xffc00000 /* large (4M) page frame mask */ /* * various short-hand protection codes |