Subversion Repositories HelenOS

Rev

Rev 2409 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2198 jancik 1
/*
2236 kebrt 2
 * Copyright (c) 2007 Pavel Jancik, Michal Kebrt
2198 jancik 3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
2323 kebrt 29
 
2236 kebrt 30
/** @addtogroup arm32boot
2198 jancik 31
 * @{
32
 */
2349 kebrt 33
/** @file
34
 *  @brief Memory management used while booting the kernel.
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.
44
 *  Will belong to domain 0. No cache or buffering is enabled.
45
 *  
2323 kebrt 46
 *  @param pte    Section entry to initialize.
47
 *  @param frame  First frame in the section (frame number).
48
 *
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;
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
{
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);
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
2339 kebrt 78
    for (i = first_kernel_page; i < PTL0_ENTRIES; i++) {
79
        init_pte_level0_section(&page_table[i], i - first_kernel_page);
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();
2236 kebrt 87
    set_ptl0_address(page_table);
2254 kebrt 88
    enable_paging();
89
}
2198 jancik 90
 
2323 kebrt 91
 
2198 jancik 92
/** @}
93
 */
94