85 lines
3.4 KiB
C++
85 lines
3.4 KiB
C++
/**
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* PROJECT: ExectOS
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* COPYRIGHT: See COPYING.md in the top level directory
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* FILE: xtoskrnl/mm/i686/mmgr.cc
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* DESCRIPTION: Memory Manager
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* DEVELOPERS: Aiken Harris <harraiken91@gmail.com>
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*/
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#include <xtos.hh>
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/**
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* Initializes the kernel's virtual memory layout.
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*
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* @return This routine does not return any value.
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*
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* @since XT 1.0
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*/
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XTAPI
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VOID
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MM::Manager::InitializeMemoryLayout(VOID)
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{
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ULONG_PTR PagedPoolSize, PteCount;
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PFN_NUMBER PfnDatabaseSize, PhysicalPages;
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ULONG PtesPerPage;
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/* Define the number of system PTEs */
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NumberOfSystemPtes = MM_DEFAULT_NUMBER_SYSTEM_PTES;
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/* Retrieve the number of physical pages */
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PhysicalPages = MM::Pfn::GetNumberOfPhysicalPages();
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/* Verify the number of physical pages */
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if(PhysicalPages < 8192)
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{
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/* Less than 32MiB of physical memory (8192 pages), use the minimum number of system PTEs */
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NumberOfSystemPtes = MM_MINIMUM_NUMBER_SYSTEM_PTES;
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}
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else if(PhysicalPages > 32768)
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{
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/* More than 128MiB of physical memory (32768 pages), use the maximum number of system PTEs */
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NumberOfSystemPtes = MM_MAXIMUM_NUMBER_SYSTEM_PTES;
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}
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/* Check if 3-level paging (PAE) is enabled */
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if(MM::Paging::GetXpaStatus())
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{
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/* Configure memory layout for 3-level paging, using 36bit address space and providing a 64 GB address space */
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MemoryLayout.PfnDatabaseAddress = (PMMPFN)0xB0000000;
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MemoryLayout.SelfMapAddress = (PVOID)MM_PTE_BASE;
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/* Define the non-paged and paged pool regions */
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MemoryLayout.NonPagedPoolStart = (PVOID)((ULONG_PTR)MemoryLayout.PfnDatabaseAddress + PfnDatabaseSize * MM_PAGE_SIZE);
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MemoryLayout.NonPagedPoolEnd = (PVOID)0xEEFFFFFF;
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MemoryLayout.PagedPoolStart = (PVOID)0xE2000000;
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MemoryLayout.PagedPoolEnd = (PVOID)(((ULONG_PTR)MemoryLayout.PagedPoolStart + PagedPoolSize) - 1);
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/* Define hyperspace, system PTE space, and the user space limit */
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MemoryLayout.HyperSpaceStart = (PVOID)0xC0800000;
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MemoryLayout.HyperSpaceEnd = (PVOID)0xC0BFFFFF;
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MemoryLayout.SystemSpaceStart = (PVOID)0xC0C00000;
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MemoryLayout.SystemSpaceEnd = (PVOID)((ULONG_PTR)MemoryLayout.SystemSpaceStart + (NumberOfSystemPtes + 1) * MM_PAGE_SIZE);
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MemoryLayout.UserSpaceEnd = (PVOID)0x7FFEFFFF;
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}
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else
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{
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/* Configure memory layout for 2-level paging, using 32bit address space and providing a 4 GB address space */
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MemoryLayout.PfnDatabaseAddress = (PMMPFN)0xB0000000;
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MemoryLayout.SelfMapAddress = (PVOID)MM_PTE_BASE;
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/* Define the non-paged and paged pool regions */
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MemoryLayout.NonPagedPoolStart = (PVOID)((ULONG_PTR)MemoryLayout.PfnDatabaseAddress + PfnDatabaseSize * MM_PAGE_SIZE);
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MemoryLayout.NonPagedPoolEnd = (PVOID)0xFFBE0000;
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MemoryLayout.PagedPoolStart = (PVOID)0xE1000000;
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MemoryLayout.PagedPoolEnd = (PVOID)(((ULONG_PTR)MemoryLayout.PagedPoolStart + PagedPoolSize) - 1);
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/* Define hyperspace, system PTE space, and the user space limit */
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MemoryLayout.HyperSpaceStart = (PVOID)0xC0400000;
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MemoryLayout.HyperSpaceEnd = (PVOID)0xC07FFFFF;
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MemoryLayout.SystemSpaceStart = (PVOID)0xC0800000;
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MemoryLayout.SystemSpaceEnd = (PVOID)((ULONG_PTR)MemoryLayout.SystemSpaceStart + (NumberOfSystemPtes + 1) * MM_PAGE_SIZE);
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MemoryLayout.UserSpaceEnd = (PVOID)0x7FFEFFFF;
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}
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}
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