56 lines
1.4 KiB
C
56 lines
1.4 KiB
C
#include <stdint.h>
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#include <stdio.h>
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#include <kernel/paging.h>
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//extern uint32_t endkernel; // found in link.ld
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/**
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* The page table must be page aligned (aligned at 4KiB)
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*
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*
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* This is a temporary solution, as we want a page frame allocator, to properly get page frames.. but this works for now
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*/
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uint32_t page_directory[PAGE_DIRECTORY_ENTRIES] __attribute__((aligned(4096)));
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uint32_t first_page_table[PAGE_TABLE_ENTRIES] __attribute__((aligned(4096)));
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void setup_page_table(void)
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{
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uint32_t i;
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for (i = 0; i < PAGE_TABLE_ENTRIES; i++) {
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first_page_table[i] = (i * 0x1000) | 3; // supervisor, r/w, present
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}
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puts("test");
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}
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void setup_page_dir(void)
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{
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setup_page_table();
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/**
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* Now that we have a page directory, we need to blank it.
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*
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* The page directory should have exactly 1024 entries. We will set each entry to not present, so that the if the
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* MMU looks for that page table, it will see that it is not there yet.
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*/
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int i;
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for (i = 0; i < PAGE_DIRECTORY_ENTRIES; i++) {
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// This sets the following flags to the pages:
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// Supervisor: Only kernel-mode can access them
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// Write Enabled: It can be both read from and written to
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// Not Present: The page table is not present
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page_directory[i] = 0x00000002;
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}
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page_directory[0] = ((uint32_t) first_page_table) | 3;
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}
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void setup_paging(void)
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{
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setup_page_dir();
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load_page_directory(page_directory);
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enable_paging();
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}
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