virtual.cpp

来自「自己在wince的环境下做的一移动数字电视驱动」· C++ 代码 · 共 64 行

#include "Virtual.h"


#define USE_MMMAP

#ifdef USE_MMMAP

#include <ceddk.h>

volatile LPVOID SetVirtual(unsigned int physical_addr, unsigned int mem_size)
{
	LPVOID pVirtual;

	PHYSICAL_ADDRESS PA;
	PA.LowPart = (DWORD)(physical_addr);

	pVirtual = (DWORD*)MmMapIoSpace(PA,mem_size, FALSE); 
	if(!pVirtual){
		printf("MmMapIoSpace GetLastError() : %d\n",GetLastError());
		return NULL;
	}
	return pVirtual;
}

void FreeVirtual(LPVOID virtual_ptr, unsigned int mem_size)
{
	MmUnmapIoSpace(virtual_ptr, mem_size);
}

#else

volatile LPVOID SetVirtual(unsigned int physical_addr, unsigned int mem_size)
{
	LPVOID pVirtual;

	if(physical_addr & 0xFF)
		return NULL;

	pVirtual = VirtualAlloc(0, mem_size, MEM_RESERVE, PAGE_NOACCESS);
	if(!pVirtual) {
		printf("VirtualAlloc GetLastError() : %d\n",GetLastError());
		return NULL;
	}

	if( !VirtualCopy((void*)pVirtual, (void*)(physical_addr >> 8), mem_size, PAGE_READWRITE | PAGE_NOCACHE | PAGE_PHYSICAL)){
		printf("VirtualCopy GetLastError() : %d\n",GetLastError());
		VirtualFree((void*)pVirtual, 0, MEM_RELEASE);
		return NULL;
	}

	return pVirtual;
}

void FreeVirtual(LPVOID virtual_ptr, unsigned int mem_size)
{
	if(VirtualFree((void*)virtual_ptr, 0, MEM_RELEASE) == 0)
		printf("VirtualFree GetLastError() : %d\n",GetLastError());
}


#endif