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