| 1 | ;
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| 2 | ; PAGING.INC -- Manage page tables
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| 3 | ;
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| 4 | ; Copyright (c) 1991-1999 by Eberhard Mattes
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| 5 | ;
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| 6 | ; This file is part of emx.
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| 7 | ;
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| 8 | ; emx is free software; you can redistribute it and/or modify it
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| 9 | ; under the terms of the GNU General Public License as published by
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| 10 | ; the Free Software Foundation; either version 2, or (at your option)
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| 11 | ; any later version.
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| 12 | ;
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| 13 | ; emx is distributed in the hope that it will be useful,
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| 14 | ; but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 15 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 16 | ; GNU General Public License for more details.
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| 17 | ;
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| 18 | ; You should have received a copy of the GNU General Public License
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| 19 | ; along with emx; see the file COPYING. If not, write to
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| 20 | ; the Free Software Foundation, 59 Temple Place - Suite 330,
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| 21 | ; Boston, MA 02111-1307, USA.
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| 22 | ;
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| 23 | ; See emx.asm for a special exception.
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| 24 | ;
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| 25 |
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| 26 | ;
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| 27 | ; Bits in a page table entry which are used by the processor
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| 28 | ;
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| 29 | PAGE_PRESENT = 01H ; Page present
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| 30 | PAGE_WRITE = 02H ; Page writable
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| 31 | PAGE_USER = 04H ; Not a supervisor page
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| 32 | PAGE_ACCESSED = 20H ; Page has been accessed
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| 33 | PAGE_DIRTY = 40H ; Page is dirty
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| 34 | ;
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| 35 | ; Bits in a page table entry which are available for OS use
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| 36 | ;
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| 37 | PAGE_LOCKED = 200H ; Page not swappable
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| 38 | PAGE_ALLOC = 400H ; Memory allocated
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| 39 | PAGE_UNUSED_2 = 800H ; Unused
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| 40 |
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| 41 | ;
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| 42 | ; PAGE_CLEAR is used with AND for clearing the address and the
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| 43 | ; present, dirty, and accessed bits of a page table entry
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| 44 | ;
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| 45 | PAGE_PDA = PAGE_PRESENT OR PAGE_DIRTY OR PAGE_ACCESSED
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| 46 | PAGE_CLEAR = 0FFFH AND NOT PAGE_PDA
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| 47 |
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| 48 | ;
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| 49 | ; User ID for supervisor (used in swapper table entries)
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| 50 | ;
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| 51 | PIDX_SV = 0FFH ; Supervisor page
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| 52 |
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| 53 |
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| 54 | IFNDEF __PAGING
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| 55 |
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| 56 | SV_DATA SEGMENT
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| 57 |
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| 58 | EXTRN LIN_START:DWORD ; First usable linear address
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| 59 | EXTRN PAGE_DIR_PHYS:DWORD ; Phys. addr. of page directory
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| 60 | EXTRN PAGE_DIR_SEG:WORD ; Segment of page directory
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| 61 | EXTRN PAGING:BYTE ; Paging enabled
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| 62 | EXTRN PAGE_TAB0_SEG:WORD ; Seg. of 0th page table (VCPI)
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| 63 |
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| 64 | SV_DATA ENDS
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| 65 |
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| 66 |
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| 67 | SV_CODE SEGMENT
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| 68 |
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| 69 | EXTRN INIT_PAGES:NEAR, ALLOC_PAGES:NEAR, INIT_PAGE_BMAP:NEAR
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| 70 | EXTRN SET_PAGES:NEAR, CLEAR_TLB:NEAR, INIT_LIN_MAP:NEAR
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| 71 | EXTRN FREE_LIN:NEAR, FREE_PAGES:NEAR, GET_FREE_PAGE:NEAR
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| 72 | EXTRN FREE_AVAIL:NEAR, CLEAR_DIRTY:NEAR
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| 73 | EXTRN MAYBE_MAP_PAGE:NEAR
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| 74 |
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| 75 | SV_CODE ENDS
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| 76 |
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| 77 |
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| 78 | INIT_CODE SEGMENT
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| 79 |
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| 80 | EXTRN INIT_PAGING:NEAR, MAP_PAGES:NEAR, RM_TO_PHYS:NEAR
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| 81 |
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| 82 | INIT_CODE ENDS
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| 83 |
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| 84 | ENDIF
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