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#include "PhysMem.ns.h"
#include <Bitset.class.h>
#include <VTManager/VirtualTerminal.proto.h>
PageDirectory* kernelPageDirectory;
namespace PhysMem {
u32int nframes;
Bitset *frames;
void initPaging(u32int mem_size) {
nframes = mem_size / 0x1000;
frames = new Bitset(nframes);
kernelPageDirectory = new (Mem::alloc(sizeof(PageDirectory), true)) PageDirectory();
u32int i = 0xC0000000;
while (i < Mem::placementAddress) {
page_t *p2 = kernelPageDirectory->getPage(i, true);
allocFrame(p2, false, false);
i += 0x1000;
}
//Also map thoses pages at begning of virtual memory
for (u32int i = 0; i < (Mem::placementAddress - 0xC0000000) / 0x100000; i++) {
kernelPageDirectory->tablesPhysical[i] = kernelPageDirectory->tablesPhysical[768 + i];
kernelPageDirectory->tables[i] = kernelPageDirectory->tables[768 + i];
}
DEBUG_HEX((u32int)kernelPageDirectory->physicalAddr); DEBUG(" is page dir phys addr.");
kernelPageDirectory->switchTo();
DEBUG("Paging enabled !");
Mem::pagingEnabled = true;
}
void removeTemporaryPages() {
for (u32int i = 0; i < (Mem::placementAddress - 0xC0000000) / 0x100000; i++) {
kernelPageDirectory->tablesPhysical[i] = 0;
kernelPageDirectory->tables[i] = 0;
}
}
void allocFrame(page_t *page, bool is_user, bool is_writable) {
if (page->frame != 0) {
return;
} else {
u32int idx = frames->firstFreeBit();
if (idx == (u32int) - 1) PANIC("No more free frames !");
frames->setBit(idx);
page->present = 1;
page->user = (is_user ? 1 : 0);
page->rw = (is_writable ? 1 : 0);
page->frame = idx;
}
}
void freeFrame(page_t *page) {
if (page->frame == 0) {
return;
} else {
if (page->frame >= 0x100) { //First 1M are reserved (system)
frames->clearBit(page->frame);
}
page->present = 0;
page->frame = 0;
}
}
u32int free() {
return nframes - frames->usedBits();
}
u32int total() {
return nframes;
}
}
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