Rev 2468 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2468 | jermar | 1 | /* |
| 2 | * Copyright (c) 2007 Pavel Jancik |
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| 3 | * Copyright (c) 2007 Michal Kebrt |
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| 4 | * All rights reserved. |
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| 5 | * |
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| 6 | * Redistribution and use in source and binary forms, with or without |
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| 7 | * modification, are permitted provided that the following conditions |
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| 8 | * are met: |
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| 9 | * |
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| 10 | * - Redistributions of source code must retain the above copyright |
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| 11 | * notice, this list of conditions and the following disclaimer. |
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| 12 | * - Redistributions in binary form must reproduce the above copyright |
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| 13 | * notice, this list of conditions and the following disclaimer in the |
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| 14 | * documentation and/or other materials provided with the distribution. |
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| 15 | * - The name of the author may not be used to endorse or promote products |
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| 16 | * derived from this software without specific prior written permission. |
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| 17 | * |
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| 18 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 19 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 20 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 21 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 22 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 23 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 24 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 25 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 26 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 27 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 28 | */ |
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| 29 | |||
| 30 | |||
| 31 | /** @addtogroup arm32boot |
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| 32 | * @{ |
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| 33 | */ |
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| 34 | /** @file |
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| 35 | * @brief Memory management used while booting the kernel. |
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| 36 | * |
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| 37 | * So called "section" paging is used while booting the kernel. The term |
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| 38 | * "section" comes from the ARM architecture specification and stands for the |
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| 39 | * following: one-level paging, 1MB sized pages, 4096 entries in the page |
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| 40 | * table. |
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| 41 | */ |
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| 42 | |||
| 43 | |||
| 44 | #ifndef BOOT_arm32__MM_H |
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| 45 | #define BOOT_arm32__MM_H |
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| 46 | |||
| 47 | |||
| 48 | #ifndef __ASM__ |
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| 49 | #include "types.h" |
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| 50 | #endif |
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| 51 | |||
| 52 | |||
| 53 | /** Frame width. */ |
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| 54 | #define FRAME_WIDTH 20 |
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| 55 | |||
| 56 | /** Frame size. */ |
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| 57 | #define FRAME_SIZE (1 << FRAME_WIDTH) |
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| 58 | |||
| 59 | /** Page size in 2-level paging which is switched on later after the kernel |
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| 60 | * initialization. |
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| 61 | */ |
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| 62 | #define KERNEL_PAGE_SIZE (1 << 12) |
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| 63 | |||
| 64 | |||
| 65 | #ifndef __ASM__ |
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| 66 | /** Converts kernel address to physical address. */ |
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| 67 | # define KA2PA(x) (((uintptr_t) (x)) - 0x80000000) |
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| 68 | /** Converts physical address to kernel address. */ |
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| 69 | # define PA2KA(x) (((uintptr_t) (x)) + 0x80000000) |
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| 70 | #else |
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| 71 | # define KA2PA(x) ((x) - 0x80000000) |
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| 72 | # define PA2KA(x) ((x) + 0x80000000) |
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| 73 | #endif |
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| 74 | |||
| 75 | |||
| 76 | /** Number of entries in PTL0. */ |
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| 77 | #define PTL0_ENTRIES (1 << 12) /* 4096 */ |
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| 78 | |||
| 79 | /** Size of an entry in PTL0. */ |
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| 80 | #define PTL0_ENTRY_SIZE 4 |
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| 81 | |||
| 82 | /** Returns number of frame the address belongs to. */ |
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| 83 | #define ADDR2PFN(addr) (((uintptr_t) (addr)) >> FRAME_WIDTH) |
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| 84 | |||
| 85 | /** Describes "section" page table entry (one-level paging with 1MB sized pages). */ |
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| 86 | #define PTE_DESCRIPTOR_SECTION 0x2 |
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| 87 | |||
| 88 | /** Page table access rights: user - no access, kernel - read/write. */ |
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| 89 | #define PTE_AP_USER_NO_KERNEL_RW 0x1 |
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| 90 | |||
| 91 | |||
| 92 | #ifndef __ASM__ |
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| 93 | |||
| 94 | |||
| 95 | /** Page table level 0 entry - "section" format is used (one-level paging, 1MB |
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| 96 | * sized pages). Used only while booting the kernel. |
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| 97 | */ |
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| 98 | typedef struct { |
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| 99 | unsigned descriptor_type : 2; |
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| 100 | unsigned bufferable : 1; |
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| 101 | unsigned cacheable : 1; |
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| 102 | unsigned impl_specific : 1; |
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| 103 | unsigned domain : 4; |
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| 104 | unsigned should_be_zero_1 : 1; |
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| 105 | unsigned access_permission : 2; |
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| 106 | unsigned should_be_zero_2 : 8; |
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| 107 | unsigned section_base_addr : 12; |
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| 108 | } __attribute__ ((packed)) pte_level0_section_t; |
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| 109 | |||
| 110 | |||
| 111 | /** Page table that holds 1:1 virtual to physical mapping used while booting the |
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| 112 | * kernel. |
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| 113 | */ |
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| 114 | extern pte_level0_section_t page_table[PTL0_ENTRIES]; |
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| 115 | |||
| 116 | extern void mmu_start(void); |
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| 117 | |||
| 118 | |||
| 119 | /** Enables paging. */ |
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| 120 | static inline void enable_paging() |
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| 121 | { |
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| 122 | /* c3 - each two bits controls access to the one of domains (16) |
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| 123 | * 0b01 - behave as a client (user) of a domain |
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| 124 | */ |
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| 125 | asm volatile ( |
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| 126 | /* behave as a client of domains */ |
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| 127 | "ldr r0, =0x55555555\n" |
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| 128 | "mcr p15, 0, r0, c3, c0, 0\n" |
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| 129 | |||
| 130 | /* current settings */ |
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| 131 | "mrc p15, 0, r0, c1, c0, 0\n" |
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| 132 | |||
| 133 | /* mask to enable paging */ |
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| 134 | "ldr r1, =0x00000001\n" |
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| 135 | "orr r0, r0, r1\n" |
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| 136 | |||
| 137 | /* store settings */ |
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| 138 | "mcr p15, 0, r0, c1, c0, 0\n" |
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| 139 | : |
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| 140 | : |
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| 141 | : "r0", "r1" |
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| 142 | ); |
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| 143 | } |
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| 144 | |||
| 145 | |||
| 146 | /** Sets the address of level 0 page table to CP15 register 2. |
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| 147 | * |
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| 148 | * @param pt Address of a page table to set. |
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| 149 | */ |
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| 150 | static inline void set_ptl0_address(pte_level0_section_t* pt) |
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| 151 | { |
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| 152 | asm volatile ( |
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| 153 | "mcr p15, 0, %0, c2, c0, 0\n" |
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| 154 | : |
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| 155 | : "r" (pt) |
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| 156 | ); |
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| 157 | } |
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| 158 | |||
| 159 | |||
| 160 | #endif |
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| 161 | |||
| 162 | #endif |
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| 163 | |||
| 164 | /** @} |
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| 165 | */ |
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| 166 |