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, Michal Kebrt |
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| 3 | * All rights reserved. |
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| 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 | |||
| 29 | |||
| 30 | /** @addtogroup arm32boot |
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| 31 | * @{ |
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| 32 | */ |
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| 33 | /** @file |
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| 34 | * @brief Memory management used while booting the kernel. |
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| 35 | */ |
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| 36 | |||
| 37 | |||
| 38 | #include "mm.h" |
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| 39 | |||
| 40 | |||
| 41 | /** Initializes "section" page table entry. |
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| 42 | * |
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| 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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| 46 | * @param pte Section entry to initialize. |
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| 47 | * @param frame First frame in the section (frame number). |
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| 48 | * |
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| 49 | * @note If frame is not 1MB aligned, first lower 1MB aligned frame will be |
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| 50 | * used. |
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| 51 | */ |
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| 52 | static void init_pte_level0_section(pte_level0_section_t* pte, |
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| 53 | unsigned int frame) |
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| 54 | { |
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| 55 | pte->descriptor_type = PTE_DESCRIPTOR_SECTION; |
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| 56 | pte->bufferable = 0; |
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| 57 | pte->cacheable = 0; |
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| 58 | pte->impl_specific = 0; |
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| 59 | pte->domain = 0; |
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| 60 | pte->should_be_zero_1 = 0; |
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| 61 | pte->access_permission = PTE_AP_USER_NO_KERNEL_RW; |
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| 62 | pte->should_be_zero_2 = 0; |
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| 63 | pte->section_base_addr = frame; |
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| 64 | } |
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| 65 | |||
| 66 | /** Initializes page table used while booting the kernel. */ |
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| 67 | static void init_page_table(void) |
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| 68 | { |
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| 69 | int i; |
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| 70 | const unsigned int first_kernel_page = ADDR2PFN(PA2KA(0)); |
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| 71 | |||
| 72 | /* Create 1:1 virtual-physical mapping (in lower 2GB). */ |
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| 73 | for (i = 0; i < first_kernel_page; i++) { |
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| 74 | init_pte_level0_section(&page_table[i], i); |
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| 75 | } |
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| 76 | |||
| 77 | /* |
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| 78 | * Create 1:1 virtual-physical mapping in kernel space (upper 2GB), |
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| 79 | * physical addresses start from 0. |
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| 80 | */ |
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| 81 | for (i = first_kernel_page; i < PTL0_ENTRIES; i++) { |
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| 82 | init_pte_level0_section(&page_table[i], i - first_kernel_page); |
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| 83 | } |
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| 84 | } |
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| 85 | |||
| 86 | /** Starts the MMU - initializes page table and enables paging. */ |
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| 87 | void mmu_start() { |
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| 88 | init_page_table(); |
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| 89 | set_ptl0_address(page_table); |
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| 90 | enable_paging(); |
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| 91 | } |
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| 92 | |||
| 93 | /** @} |
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| 94 | */ |
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| 95 |