242 lines
12 KiB
C
242 lines
12 KiB
C
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/*
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* This file is part of the COMROGUE Operating System for Raspberry Pi
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*
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* Copyright (c) 2013, Eric J. Bowersox / Erbosoft Enterprises
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* All rights reserved.
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*
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* This program is free for commercial and non-commercial use as long as the following conditions are
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* adhered to.
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*
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* Copyright in this file remains Eric J. Bowersox and/or Erbosoft, and as such any copyright notices
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* in the code are not to be removed.
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*
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* Redistribution and use in source and binary forms, with or without modification, are permitted
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* provided that the following conditions are met:
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*
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* * Redistributions of source code must retain the above copyright notice, this list of conditions and
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* the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
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* the following disclaimer in the documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
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* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* "Raspberry Pi" is a trademark of the Raspberry Pi Foundation.
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*/
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#ifndef __MMU_H_INCLUDED
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#define __MMU_H_INCLUDED
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#ifdef __COMROGUE_INTERNALS__
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/*----------------------------------------------
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* BCM2835 ARM Memory Management Unit constants
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*----------------------------------------------
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*/
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/* Memory system constants */
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#define SYS_PAGE_SIZE 4096 /* standard page size for normal page */
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#define SYS_PAGE_BITS 12 /* log2(SYS_PAGE_SIZE), number of bits in a page address */
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#define SYS_TTB0_SIZE 8192 /* TTB0 must be located on this boundary and is this size */
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#define SYS_TTB1_SIZE 16384 /* TTB1 must be located on this boundary and is this size */
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#define SYS_TTB1_ENTRIES 4096 /* SYS_TTB1_SIZE/4, number of entries in TTB1 */
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#define SYS_TTB_BITS 12 /* log2(SYS_TTB1_SIZE/4), number of bits in a TTB address */
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#define SYS_SEC_SIZE 1048576 /* standard section size */
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#define SYS_SEC_PAGES 256 /* SYS_SEC_SIZE/SYS_PAGE_SIZE, number of pages equivalent to a section */
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#define SYS_PGTBL_SIZE 1024 /* page tables must be located on this boundary and are this size */
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#define SYS_PGTBL_BITS 8 /* log2(SYS_PGTBL_SIZE/4), number of bits in a page table address */
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#define SYS_PGTBL_ENTRIES 256 /* SYS_PGTBL_SIZE/4, number of entries in a page table */
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/* Section descriptor bits */
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#define TTBSEC_PXN 0x00000001 /* Privileged Execute-Never */
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#define TTBSEC_ALWAYS 0x00000002 /* this bit must always be set for a section */
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#define TTBSEC_B 0x00000004 /* memory region attribute bit */
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#define TTBSEC_C 0x00000008 /* memory region attribute bit */
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#define TTBSEC_XN 0x00000010 /* Execute-Never */
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#define TTBSEC_DOM_MASK 0x000001E0 /* domain indicator */
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#define TTBSEC_P 0x00000200 /* ECC enabled (not supported) */
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#define TTBSEC_AP 0x00000C00 /* access permission bits */
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#define TTBSEC_TEX 0x00007000 /* memory type flags */
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#define TTBSEC_APX 0x00008000 /* access permission extended */
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#define TTBSEC_S 0x00010000 /* Shared */
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#define TTBSEC_NG 0x00020000 /* Not Global */
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#define TTBSEC_SUPER 0x00040000 /* Set for supersections */
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#define TTBSEC_NS 0x00080000 /* Not Secure */
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#define TTBSEC_ALLFLAGS 0x000FFFFF /* "all flags" mask */
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#define TTBSEC_BASE 0xFFF00000 /* section base address mask */
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#define TTBSEC_SBASE 0xFF000000 /* supersection base address mask */
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#define TTBSEC_SBASEHI 0x00F00000 /* supersection high base address mask */
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/* AP bits for the standard access control model */
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#define TTBSEC_AP00 0x00000000 /* no access */
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#define TTBSEC_AP01 0x00000400 /* supervisor only access */
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#define TTBSEC_AP10 0x00000800 /* user read-only access */
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#define TTBSEC_AP11 0x00000C00 /* user read-write access */
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/* AP bits for the simplified access control model */
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#define TTBSEC_ACCESS 0x00000400 /* Accessed bit */
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#define TTBSEC_AP_PL0 0x00000800 /* enable access at PL0 */
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#define TTBSEC_AP_RO TTBSEC_APX /* read-only access */
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/* Page table descriptor bits */
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#define TTBPGTBL_ALWAYS 0x00000001 /* bottom-two bits are always this */
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#define TTBPGTBL_PXN 0x00000004 /* Privileged Execute-Never */
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#define TTBPGTBL_NS 0x00000008 /* Not Secure */
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#define TTBPGTBL_DOM_MASK 0x000001E0 /* domain indicator */
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#define TTBPGTBL_P 0x00000200 /* ECC enabled (not supported) */
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#define TTBPGTBL_ALLFLAGS 0x000003FF /* "all flags" mask */
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#define TTBPGTBL_BASE 0xFFFFFC00 /* page table base address mask */
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/* Bits to query the type of TTB entry we're looking at */
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#define TTBQUERY_MASK 0x00000003 /* bits we can query */
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#define TTBQUERY_FAULT 0x00000000 /* indicates a fault */
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#define TTBQUERY_PGTBL 0x00000001 /* indicates a page table */
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#define TTBQUERY_SEC 0x00000002 /* indicates a section */
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#define TTBQUERY_PXNSEC 0x00000003 /* indicates a section with PXN (or reserved) */
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/* Small page table entry bits */
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#define PGTBLSM_XN 0x00000001 /* Execute-Never */
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#define PGTBLSM_ALWAYS 0x00000002 /* this bit must always be set for a page table entry */
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#define PGTBLSM_B 0x00000004 /* memory region attribute bit */
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#define PGTBLSM_C 0x00000008 /* memory region attribute bit */
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#define PGTBLSM_AP 0x00000030 /* access permission bits */
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#define PGTBLSM_TEX 0x000001C0 /* memory type flags */
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#define PGTBLSM_APX 0x00000200 /* access permission extended */
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#define PGTBLSM_S 0x00000400 /* Shared */
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#define PGTBLSM_NG 0x00000800 /* Not Global */
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#define PGTBLSM_PAGE 0xFFFFF000 /* page base address mask */
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/* AP bits for the standard access control model */
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#define PGTBLSM_AP00 0x00000000 /* no access */
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#define PGTBLSM_AP01 0x00000010 /* supervisor only access */
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#define PGTBLSM_AP10 0x00000020 /* user read-only access */
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#define PGTBLSM_AP11 0x00000030 /* user read-write access */
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/* Bits to query the type of page table entry we're looking at */
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#define PGQUERY_MASK 0x00000003 /* bits we can query */
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#define PGQUERY_FAULT 0x00000000 /* indicates a fault */
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#define PGQUERY_LG 0x00000001 /* large page (64K) */
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#define PGQUERY_SM 0x00000002 /* small page (4K) */
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#define PGQUERY_SM_XN 0x00000003 /* small page with Execute-Never set */
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#ifndef __ASM__
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/*-------------------------------------------------------
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* Data structures defining the TTB and page table data.
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*-------------------------------------------------------
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*/
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/* TTB fault descriptor */
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typedef struct tagTTBFAULT {
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unsigned always0 : 2; /* bits are always 0 for a fault entry */
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unsigned ignored : 30; /* ignored (COMROGUE may define these later) */
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} TTBFAULT, *PTTBFAULT;
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/* TTB page table descriptor */
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typedef struct tagTTBPGTBL {
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unsigned always01 : 2; /* bits are always 01 for a page table */
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unsigned pxn : 1; /* Privileged Execute-Never bit */
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unsigned ns : 1; /* Not Secure bit */
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unsigned always0 : 1; /* bit is always 0 for a page table */
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unsigned domain : 4; /* protection domain */
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unsigned p : 1; /* not supported, should be 0 */
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unsigned baseaddr : 22; /* upper 22 bits of base address of page table */
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} TTBPGTBL, *PTTBPGTBL;
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/* TTB section descriptor */
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typedef struct tagTTBSEC {
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unsigned pxn : 1; /* Privileged Execute-Never bit */
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unsigned always1: 1; /* bit is always 1 for a section */
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unsigned b : 1; /* attribute bit ("Buffered") */
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unsigned c : 1; /* attribute bit ("Cached") */
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unsigned xn : 1; /* Execute-Never bit */
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unsigned domain : 4; /* protection domain */
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unsigned p : 1; /* not supported, should be 0 */
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unsigned ap : 2; /* access permissions */
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unsigned tex : 3; /* memory type flags */
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unsigned ap2 : 1; /* access permission extension */
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unsigned s : 1; /* Shared bit */
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unsigned ng : 1; /* Not Global bit */
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unsigned always0 : 1; /* bit is always 0 for a section */
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unsigned ns : 1; /* Not Secure bit */
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unsigned baseaddr : 12; /* upper 12 bits of base address of section */
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} TTBSEC, *PTTBSEC;
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/* Single TTB entry descriptor */
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typedef union tagTTB {
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UINT32 data; /* raw data for entry */
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TTBFAULT fault; /* "fault" data */
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TTBPGTBL pgtbl; /* page table data */
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TTBSEC sec; /* 1Mb section data */
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} TTB, *PTTB;
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/* page table descriptor for a fault entry */
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typedef struct tagPGTBLFAULT {
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unsigned always0 : 2; /* bits are always 0 for a fault entry */
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unsigned ignored : 30; /* ignored (COMROGUE may define these later) */
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} PGTBLFAULT, *PPGTBLFAULT;
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/* page table descriptor for regular 4K pages */
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typedef struct tagPGTBLSM {
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unsigned xn : 1; /* Execute Never */
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unsigned always1 : 1; /* always 1 for a 4k small page */
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unsigned b : 1; /* attribute bit ("Buffered") */
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unsigned c : 1; /* attribute bit ("Cached") */
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unsigned ap : 2; /* access permissions */
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unsigned tex : 3; /* memory type flags */
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unsigned apx : 1; /* access permission extension */
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unsigned s : 1; /* Shared bit */
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unsigned ng : 1; /* Not Global bit */
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unsigned pgaddr : 20; /* upper 20 bits of base address of page */
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} PGTBLSM, *PPGTBLSM;
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/* single page table entry */
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typedef union tagPGTBL {
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UINT32 data; /* raw data for entry */
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PGTBLFAULT fault; /* "fault" data */
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PGTBLSM pg; /* small page descriptor */
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} PGTBL, *PPGTBL;
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/* page table auxiliary entry */
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typedef union tagPGAUX {
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UINT32 data; /* raw data for entry */
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/* TODO */
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} PGAUX, *PPGAUX;
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/* complete structure of a page table, hardware + auxiliary */
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typedef struct tagPAGETAB {
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PGTBL pgtbl[SYS_PGTBL_ENTRIES]; /* hardware page table entries */
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PGAUX pgaux[SYS_PGTBL_ENTRIES]; /* auxiliary page table entries */
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} PAGETAB, *PPAGETAB;
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/* VMA index macros */
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#define mmVMA2TTBIndex(vma) (((vma) >> (SYS_PAGE_BITS + SYS_PGTBL_BITS)) & ((1 << SYS_TTB_BITS) - 1))
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#define mmVMA2PGTBLIndex(vma) (((vma) >> SYS_PAGE_BITS) & ((1 << SYS_PGTBL_BITS) - 1))
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/*
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* Data structures for the Master Page Database.
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*/
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/* internal structure of a MPDB entry */
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typedef struct tagMPDB1 {
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unsigned next : 20; /* index of "next" entry in list */
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unsigned tag : 12; /* page tag */
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} MPDB1;
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/* The MPDB entry itself. */
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typedef union tagMPDB {
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UINT32 raw; /* raw data */
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MPDB1 d; /* structured data */
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} MPDB, *PMPDB;
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#endif /* __ASM__ */
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#endif /* __COMROGUE_INTERNALS__ */
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#endif /* __MMU_H_INCLUDED */
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