55 lines
1.4 KiB
C++
55 lines
1.4 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/paging.cc
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* DESCRIPTION: Architecture dependent paging support
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* DEVELOPERS: Rafal Kupiec <belliash@codingworkshop.eu.org>
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* Aiken Harris <harraiken91@gmail.com>
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*/
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#include <xtos.hh>
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/**
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* Checks if eXtended Physical Addressing (XPA) is enabled.
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*
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* @return This routine returns TRUE if PAE is enabled, or FALSE otherwise.
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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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BOOLEAN
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MM::Paging::GetExtendedPhysicalAddressingStatus(VOID)
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{
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/* Check if PAE is enabled */
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return ((AR::CpuFunc::ReadControlRegister(4) & CR4_PAE) != 0) ? TRUE : FALSE;
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}
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/**
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* Fills a section of memory with zeroes like RtlZeroMemory(), but in more efficient way.
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*
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* @param Address
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* Supplies an address of the page to be filled with zeroes.
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*
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* @param Size
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* Number of bytes to be filled with zeros. This always should be a multiply of page size.
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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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XTFASTCALL
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VOID
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MM::Paging::ZeroPages(IN PVOID Address,
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IN ULONG Size)
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{
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__asm__ volatile("xor %%eax, %%eax\n"
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"rep stosb"
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: "=D"(Address),
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"=c"(Size)
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: "0"(Address),
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"1"(Size),
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"a"(0)
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: "memory");
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}
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