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2198 | jancik | 1 | /* |
2236 | kebrt | 2 | * Copyright (c) 2007 Pavel Jancik, Michal Kebrt |
2198 | jancik | 3 | * All rights reserved. |
4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * |
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9 | * - Redistributions of source code must retain the above copyright |
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10 | * notice, this list of conditions and the following disclaimer. |
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11 | * - Redistributions in binary form must reproduce the above copyright |
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12 | * notice, this list of conditions and the following disclaimer in the |
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13 | * documentation and/or other materials provided with the distribution. |
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14 | * - The name of the author may not be used to endorse or promote products |
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15 | * derived from this software without specific prior written permission. |
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16 | * |
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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27 | */ |
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28 | |||
2323 | kebrt | 29 | |
2236 | kebrt | 30 | /** @addtogroup arm32boot |
2198 | jancik | 31 | * @{ |
32 | */ |
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2349 | kebrt | 33 | /** @file |
34 | * @brief Memory management used while booting the kernel. |
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2198 | jancik | 35 | */ |
2236 | kebrt | 36 | |
2323 | kebrt | 37 | |
2198 | jancik | 38 | #include "mm.h" |
39 | |||
2254 | kebrt | 40 | |
2323 | kebrt | 41 | /** Initializes "section" page table entry. |
2236 | kebrt | 42 | * |
43 | * Will be readable/writable by kernel with no access from user mode. |
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44 | * Will belong to domain 0. No cache or buffering is enabled. |
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45 | * |
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2323 | kebrt | 46 | * @param pte Section entry to initialize. |
47 | * @param frame First frame in the section (frame number). |
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48 | * |
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2353 | kebrt | 49 | * @note If frame is not 1MB aligned, first lower 1MB aligned frame will be used. |
2234 | jancik | 50 | */ |
2339 | kebrt | 51 | static void init_pte_level0_section(pte_level0_section_t* pte, unsigned int frame) |
2254 | kebrt | 52 | { |
2234 | jancik | 53 | pte->descriptor_type = PTE_DESCRIPTOR_SECTION; |
2254 | kebrt | 54 | pte->bufferable = 0; |
2198 | jancik | 55 | pte->cacheable = 0; |
2241 | kebrt | 56 | pte->impl_specific = 0; |
2198 | jancik | 57 | pte->domain = 0; |
58 | pte->should_be_zero_1 = 0; |
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2234 | jancik | 59 | pte->access_permission = PTE_AP_USER_NO_KERNEL_RW; |
2198 | jancik | 60 | pte->should_be_zero_2 = 0; |
2339 | kebrt | 61 | pte->section_base_addr = frame; |
2254 | kebrt | 62 | } |
2198 | jancik | 63 | |
64 | |||
2323 | kebrt | 65 | /** Initializes page table used while booting the kernel. */ |
2254 | kebrt | 66 | static void init_page_table(void) |
67 | { |
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2198 | jancik | 68 | int i; |
2339 | kebrt | 69 | const unsigned int first_kernel_page = ADDR2PFN(PA2KA(0)); |
2236 | kebrt | 70 | |
2323 | kebrt | 71 | // create 1:1 virtual-physical mapping (in lower 2GB) |
2339 | kebrt | 72 | for (i = 0; i < first_kernel_page; i++) { |
73 | init_pte_level0_section(&page_table[i], i); |
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2234 | jancik | 74 | } |
2198 | jancik | 75 | |
2323 | kebrt | 76 | // create 1:1 virtual-physical mapping in kernel space (upper 2GB), |
77 | // physical addresses start from 0 |
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2339 | kebrt | 78 | for (i = first_kernel_page; i < PTL0_ENTRIES; i++) { |
79 | init_pte_level0_section(&page_table[i], i - first_kernel_page); |
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2234 | jancik | 80 | } |
2254 | kebrt | 81 | } |
82 | |||
83 | |||
2409 | kebrt | 84 | /** Starts the MMU - initializes page table and enables paging. */ |
2254 | kebrt | 85 | void mmu_start() { |
86 | init_page_table(); |
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2236 | kebrt | 87 | set_ptl0_address(page_table); |
2254 | kebrt | 88 | enable_paging(); |
89 | } |
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2198 | jancik | 90 | |
2323 | kebrt | 91 | |
2198 | jancik | 92 | /** @} |
93 | */ |
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94 |