luxos/exp/Memory manager/memory.c

103 lines
2.1 KiB
C
Raw Permalink Normal View History

2021-09-14 16:01:13 +00:00
/*
* mem-phys.c
*
* Created on: Aug 27, 2011
* Author: Tiberiu
*/
#include <stdlib.h>
#include "mem.h"
uint32* FrameMap;
uint32 TotalFrames;
uint32 TotalMemory;
void ConvertIndexToFrame (uint32 index, uint32* address, uint32* offset)
{
*address = (index >> 5);
*offset = index & 0x1f;
}
uint32 ConvertFrameToIndex (uint32 address, uint32 offset)
{
return (address<<5) | offset;
}
void MemPhSetFrame (uint32 frame, uint8 value)
{
uint32 addr, off;
ConvertIndexToFrame(frame, &addr, &off);
if (value) FrameMap[addr] |= 1<<off;
else FrameMap[addr] &= ~(1<<off);
}
uint32 MemPhGetFrame (uint32 frame)
{
uint32 addr, off;
ConvertIndexToFrame(frame, &addr, &off);
return FrameMap[addr] & (1<<off);
}
uint32 MemPhFindFreeFrame()
{
uint32 addr, pos;
for (addr = 0; addr < TotalFrames >> 5; addr++)
if (FrameMap[addr] != 0xffffffff)
{
for (pos = 0; (FrameMap[addr] & (1<<pos)) != 0; pos++) ;
return ConvertFrameToIndex(addr, pos);
}
return 0;
}
void MemPhAllocFrame(uint8 isKernel, uint8 isWriteable)
{
//if (page->Frame != 0) return;
uint32 free = MemPhFindFreeFrame();
if (!free) return;
LogMem("Physical: allocated frame %u.\n", free);
MemPhSetFrame(free, 1);
/*page->Present = 1;
page->User = (isKernel) ? 0 : 1;
page->Writeable = (isWriteable) ? 1 : 0;
page->Frame = free;*/
}
/*void MemPhFreeFrame()//Page* page)
{
uint32 frame = page->Frame;
if (!frame) return;
MemPhSetFrame(frame, 0);
page->Frame = 0;
}*/
void MemPhInitialize(uint32 SystemMemoryKb)
{
LogMem("Starting physical memory manager...\n");
TotalFrames = SystemMemoryKb >> 2;
TotalMemory = SystemMemoryKb;
FrameMap = (uint32*) malloc(sizeof(uint32) * (1 + (TotalFrames>>5)));
memset(FrameMap, 0, sizeof(uint32) * (1 + (TotalFrames>>5)));
LogMem("Started ok!, found %ukb total_frames=%u\n", SystemMemoryKb, TotalFrames);
}
void MemPhReserveFrames (uint32 address, uint32 length)
{
address >>= 12;
length = (length>>12) + ((length & 0xfff) > 0);
uint32 end = address + length;
for (; address < end && address < TotalFrames ; address++)
MemPhSetFrame(address, 1);
}