exectos/xtoskrnl/mm/amd64/pages.c
belliash 9ea1be96db
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Implement MmZeroPages() routine
2023-02-15 20:48:48 +01:00

43 lines
1.1 KiB
C

/**
* PROJECT: ExectOS
* COPYRIGHT: See COPYING.md in the top level directory
* FILE: xtoskrnl/mm/amd64/pages.c
* DESCRIPTION: Architecture dependent paging support
* DEVELOPERS: Rafal Kupiec <belliash@codingworkshop.eu.org>
*/
#include <xtos.h>
/**
* Fills a section of memory with zeroes like RtlZeroMemory(), but in more efficient way.
*
* @param Address
* Supplies an address of the page to be filled with zeroes.
*
* @param Size
* Number of bytes to be filled with zeros. This always should be a multiply of page size.
*
* @return This routine does not return any value.
*
* @since XT 1.0
*/
XTFASTCALL
VOID
MmZeroPages(IN PVOID Address,
IN ULONG Size)
{
asm volatile("xor %%rax, %%rax\n"
"mov %0, %%rdi\n"
"mov %1, %%ecx\n"
"shr $3, %%ecx\n"
"rep stosq\n"
:
: "m" (Address),
"m" (Size)
: "rax",
"rdi",
"ecx",
"memory");
}