Files
quark-kernel/src/mmgr/addressspace.cpp

69 lines
1.8 KiB
C++

#include "addressspace.hpp"
kernel::AddressSpace::AddressSpace(MemoryAllocator& malloc)
: malloc(malloc)
{
this->pageTables = (PageTableEntry*) 0xFFC00000;
this->pageDirectory = (PageTableEntry*) 0xFFFFF000;
}
int kernel::AddressSpace::mmap(void* start, size_t length)
{
size_t tableIndex = (size_t) start / 4096;
for(int i = (int) length; i > 0; i -= 4096)
{
size_t directoryIndex = tableIndex / 1024;
if(!pageDirectory[directoryIndex].getPresent())
{
physaddr_t newPT = malloc.allocate(4096);
if(newPT == 0)
return -1;
pageDirectory[directoryIndex] = newPT;
pageDirectory[directoryIndex].setPresent(true);
pageDirectory[directoryIndex].setUsermode(false);
pageDirectory[directoryIndex].setRw(true);
}
if(!pageTables[tableIndex].getPresent())
{
physaddr_t page = malloc.allocate(4096);
pageTables[tableIndex] = page;
pageTables[tableIndex].setUsermode(false);
pageTables[tableIndex].setRw(true);
pageTables[tableIndex].setPresent(true);
}
tableIndex++;
}
return 0;
}
int kernel::AddressSpace::munmap(void* start, size_t length)
{
if((size_t) start % 4096 != 0)
return -1;
size_t tableIndex = (size_t) start / 4096;
for(int i = (int) length; i > 0; i -= 4096)
{
size_t directoryIndex = tableIndex / 1024;
if(pageDirectory[directoryIndex].getPresent())
{
pageDirectory[directoryIndex] = 0;
pageDirectory[directoryIndex].setPresent(false);
pageDirectory[directoryIndex].setUsermode(false);
pageDirectory[directoryIndex].setRw(false);
}
tableIndex++;
}
return 0;
}
physaddr_t kernel::AddressSpace::getPhysicalAddress(void* virtualAddress)
const
{
size_t index = (size_t) virtualAddress / 4096;
PageTableEntry pte = pageTables[index];
if(pte.getPresent())
return pte.getPhysicalAddress();
else
return 0;
}