75 lines
1.8 KiB
C
75 lines
1.8 KiB
C
/*
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* memory-vi.c
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*
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* Created on: Aug 23, 2011
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* Author: Tiberiu
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*/
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#include <memory-add.h>
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#include <stdio.h>
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/*******************************
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* Data *
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*******************************/
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PageDirectory* CurrentDirectory;
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PageDirectory* KernelDirectory;
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/*******************************
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* Useful routines *
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*******************************/
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void PagingInitialize(uint32 kernel_used)
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{
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Log("Mem", "Virtual memory manager initialization started. End of kernel = 0x%x\n", kernel_used);
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PageDirectory* kernelPd = (PageDirectory*) kmalloc_a(sizeof(PageDirectory));
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memset(kernelPd, 0, sizeof(PageDirectory));
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CurrentDirectory = kernelPd;
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KernelDirectory = kernelPd;
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uint32 i;
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for (i = 0; i < kernel_used; i+=0x1000)
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MemPhAllocFrame(PagingGetPage(i, 1, kernelPd), 0, 0);
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Log("Mem", "Identity mapped first 0x%x bytes.\n", kernel_used);
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for (i = KERNEL_HEAP_START; i < KERNEL_HEAP_END; i+=0x1000)
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MemPhAllocFrame(PagingGetPage(i, 1, kernelPd), 1, 1);
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Log("Mem", "Mapped kernel space.\n");
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PagingSwitchPageDirectory (kernelPd);
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}
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void PagingSwitchPageDirectory (PageDirectory* dir)
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{
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CurrentDirectory = dir;
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asm volatile ("mov %0, %%cr3":: "r"(&dir->TablesPhysical));
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uint32 cr0;
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asm volatile ("mov %%cr0, %0": "=r"(cr0));
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cr0 |= 0x80000000;
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asm volatile ("mov %0, %%cr0":: "r"(cr0));
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Log("Mem", "Enabled paging.\n");
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}
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Page* PagingGetPage(uint32 addr, uint8 make, PageDirectory* dir)
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{
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addr >>= 12;
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uint32 tableIndex = addr >> 10;
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if (dir->Tables[tableIndex])
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return &dir->Tables[tableIndex]->Pages[addr&0x3ff];
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else if (make)
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{
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uint32 temp;
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dir->Tables[tableIndex] = (PageTable*)kmalloc_ap(sizeof(PageTable), &temp);
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memset (dir->Tables[tableIndex], 0, 0x1000);
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dir->TablesPhysical[tableIndex] = temp | 0x7;
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return &dir->Tables[tableIndex]->Pages[addr&0x3ff];
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}
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else return 0;
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}
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