[SOLVED] 64 bit page mapping doesn't work
Posted: Fri Jul 03, 2020 5:16 am
Hello,
I am currently making 64 bit paging code. It page faults when I try to access the mapped address, however. I managed to debug it enough to figure out that the problem is when it creates a PDPT, it isn't recognizing it. Here is the function
If the PDPT has already been created, it works just fine.
Thanks for your help,
nexos
I am currently making 64 bit paging code. It page faults when I try to access the mapped address, however. I managed to debug it enough to figure out that the problem is when it creates a PDPT, it isn't recognizing it. Here is the function
Code: Select all
INT HalMapAddress(VIRTUALADDR* pml4Phys, VIRTUALADDR virt, VIRTUALADDR phys, DWORD flags)
{
QWORD* mapTable = (QWORD*)TEMP_MAP_TABLE;
mapTable[PAGE_TABLE_GET_INDEX(PML4_INDEX)] = PG_PRESENT | PG_WRITEABLE | (QWORD)pml4Phys;
QWORD* pml4 = (QWORD*)PDPT_INDEX;
QWORD* pdptPhys = 0;
if((pml4[PML4_GET_INDEX(virt)] & PG_PRESENT) != PG_PRESENT)
{
pdptPhys = (QWORD*)HalAllocBlock();
if(!pdptPhys)
return 0;
pml4[PML4_GET_INDEX(virt)] = flags | (QWORD)pdptPhys;
}
else
{
pdptPhys = (QWORD*)(pml4[PML4_GET_INDEX(virt)] & PG_FRAME);
}
mapTable[PAGE_TABLE_GET_INDEX(PDPT_INDEX)] = PG_PRESENT | PG_WRITEABLE | (QWORD)pdptPhys;
QWORD* pdpt = (QWORD*)PML4_INDEX;
QWORD* dirPhys = 0;
if((pdpt[PDPT_GET_INDEX(virt)] & PG_PRESENT) != PG_PRESENT)
{
dirPhys = (QWORD*)HalAllocBlock();
if(!dirPhys)
return 0;
pdpt[PDPT_GET_INDEX(virt)] = flags | (QWORD)dirPhys;
}
else
{
dirPhys = (QWORD*)(pdpt[PDPT_GET_INDEX(virt)] & PG_FRAME);
}
mapTable[PAGE_TABLE_GET_INDEX(PDIR_INDEX)] = PG_PRESENT | PG_WRITEABLE | (QWORD)dirPhys;
QWORD* dir = (QWORD*)PDIR_INDEX;
QWORD* tablePhys = 0;
if((dir[PAGE_DIR_GET_INDEX(virt)] & PG_PRESENT) != PG_PRESENT)
{
tablePhys = (QWORD*)HalAllocBlock();
if(!tablePhys)
return 0;
dir[PAGE_DIR_GET_INDEX(virt)] = flags | (QWORD)tablePhys;
}
else
{
tablePhys = (QWORD*)(dir[PAGE_DIR_GET_INDEX(virt)] & PG_FRAME);
}
mapTable[PAGE_TABLE_GET_INDEX(PTAB_INDEX)] = PG_PRESENT | PG_WRITEABLE | (QWORD)tablePhys;
QWORD* table = (QWORD*)PTAB_INDEX;
if((table[PAGE_TABLE_GET_INDEX(virt)] & PG_PRESENT) != PG_PRESENT)
{
table[PAGE_TABLE_GET_INDEX(virt)] = flags | phys;
flush = virt;
Flush();
}
else
{
return 0;
}
return 1;
}Thanks for your help,
nexos