0,0 → 1,95 |
/* |
* Copyright (c) 2007 Pavel Jancik, Michal Kebrt |
* All rights reserved. |
* |
* Redistribution and use in source and binary forms, with or without |
* modification, are permitted provided that the following conditions |
* are met: |
* |
* - Redistributions of source code must retain the above copyright |
* notice, this list of conditions and the following disclaimer. |
* - Redistributions in binary form must reproduce the above copyright |
* notice, this list of conditions and the following disclaimer in the |
* documentation and/or other materials provided with the distribution. |
* - The name of the author may not be used to endorse or promote products |
* derived from this software without specific prior written permission. |
* |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
*/ |
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/** @addtogroup arm32boot |
* @{ |
*/ |
/** @file |
* @brief Memory management used while booting the kernel. |
*/ |
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#include "mm.h" |
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/** Initializes "section" page table entry. |
* |
* Will be readable/writable by kernel with no access from user mode. |
* Will belong to domain 0. No cache or buffering is enabled. |
* |
* @param pte Section entry to initialize. |
* @param frame First frame in the section (frame number). |
* |
* @note If frame is not 1MB aligned, first lower 1MB aligned frame will be |
* used. |
*/ |
static void init_pte_level0_section(pte_level0_section_t* pte, |
unsigned int frame) |
{ |
pte->descriptor_type = PTE_DESCRIPTOR_SECTION; |
pte->bufferable = 0; |
pte->cacheable = 0; |
pte->impl_specific = 0; |
pte->domain = 0; |
pte->should_be_zero_1 = 0; |
pte->access_permission = PTE_AP_USER_NO_KERNEL_RW; |
pte->should_be_zero_2 = 0; |
pte->section_base_addr = frame; |
} |
|
/** Initializes page table used while booting the kernel. */ |
static void init_page_table(void) |
{ |
int i; |
const unsigned int first_kernel_page = ADDR2PFN(PA2KA(0)); |
|
/* Create 1:1 virtual-physical mapping (in lower 2GB). */ |
for (i = 0; i < first_kernel_page; i++) { |
init_pte_level0_section(&page_table[i], i); |
} |
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/* |
* Create 1:1 virtual-physical mapping in kernel space (upper 2GB), |
* physical addresses start from 0. |
*/ |
for (i = first_kernel_page; i < PTL0_ENTRIES; i++) { |
init_pte_level0_section(&page_table[i], i - first_kernel_page); |
} |
} |
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/** Starts the MMU - initializes page table and enables paging. */ |
void mmu_start() { |
init_page_table(); |
set_ptl0_address(page_table); |
enable_paging(); |
} |
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/** @} |
*/ |
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