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#include "PageDirectory.class.h"
#include <MemoryManager/PhysMem.ns.h>
#include <MemoryManager/PageAlloc.ns.h>
#include <TaskManager/Task.ns.h>
extern "C" void copy_page_physical(u32int src, u32int dest);
PageDirectory::PageDirectory() {
tablesPhysical = (u32int*)PageAlloc::alloc(&physicalAddr);
for (u32int i = 0; i < 1024; i++) {
tables[i] = 0;
tablesPhysical[i] = 0;
}
}
PageDirectory::PageDirectory(PageDirectory* other) {
tablesPhysical = (u32int*)PageAlloc::alloc(&physicalAddr);
for (u32int i = 0; i < 768; i++) {
if (other->tablesPhysical[i] != 0) {
u32int tmp;
tables[i] = (page_table_t*)PageAlloc::alloc(&tmp);
tablesPhysical[i] = tmp | 0x07;
for (u32int j = 0; j < 1024; j++) {
if (!(other->tables[i]->pages[j].frame))
continue;
PhysMem::allocFrame(&tables[i]->pages[j], true, true);
tables[i]->pages[j].present = other->tables[i]->pages[j].present;
tables[i]->pages[j].rw = other->tables[i]->pages[j].rw;
tables[i]->pages[j].user = other->tables[i]->pages[j].user;
tables[i]->pages[j].accessed = other->tables[i]->pages[j].accessed;
tables[i]->pages[j].dirty = other->tables[i]->pages[j].dirty;
copy_page_physical(other->tables[i]->pages[j].frame * 0x1000, tables[i]->pages[j].frame * 0x1000);
}
} else {
tables[i] = 0;
tablesPhysical[i] = 0;
}
}
for (u32int i = 768; i < 1024; i++) { //Link kernel page tables
tablesPhysical[i] = other->tablesPhysical[i];
tables[i] = other->tables[i];
}
}
PageDirectory::~PageDirectory() {
for (int i = 0; i < 768; i++) { //Only free addresses below 0xC0000000, upper is kernel space
if (tables[i] != 0) {
for (int j = 0; j < 1024; j++) {
PhysMem::freeFrame(&(tables[i]->pages[j]));
}
PageAlloc::free((void*)tables[i]);
}
}
PageAlloc::free((void*)tablesPhysical);
}
page_t *PageDirectory::getPage(u32int address, bool make) {
address /= 0x1000;
u32int tableIdx = address / 1024;
if (tables[tableIdx] != 0) {
return &(tables[tableIdx]->pages[address % 1024]);
} else if (make) {
u32int tmp;
tables[tableIdx] = (page_table_t*)PageAlloc::alloc(&tmp);
CMem::memset((u8int*)tables[tableIdx], 0, 0x1000);
tablesPhysical[tableIdx] = tmp | 0x07;
if (tableIdx >= 768)
Task::allocKernelPageTable(tableIdx, tables[tableIdx], tablesPhysical[tableIdx]);
return &(tables[tableIdx]->pages[address % 1024]);
} else {
return 0;
}
}
void PageDirectory::allocFrame(u32int address, bool is_user, bool is_writable) {
page_t *p = getPage(address, true);
if (p != 0) PhysMem::allocFrame(p, is_user, is_writable);
}
void PageDirectory::freeFrame(u32int address) {
page_t *p = getPage(address, false);
if (p == 0) return;
PhysMem::freeFrame(p);
}
void PageDirectory::switchTo() {
asm volatile("mov %0, %%cr3" :: "r"(physicalAddr));
u32int cr0;
asm volatile("mov %%cr0, %0" : "=r"(cr0));
cr0 |= 0x80000000;
asm volatile("mov %0, %%cr0" :: "r"(cr0));
}
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