33 lines
679 B
C
33 lines
679 B
C
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#include <stdint.h>
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#include <stddef.h>
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#include "drivers/uart.h"
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#include "memory.h"
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#define PAGE_SIZE 4096
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struct Page {
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struct Page *next;
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};
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static struct Page *free_list;
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extern uint8_t _bss_end[]; // named in the linker script
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void page_init() {
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kprint("Initialising page allocator.\n");
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uintptr_t start = ((uintptr_t)_bss_end + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
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uintptr_t end = 0x88000000; // Default QEMU RAM limit
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for (uintptr_t addr = start; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
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page_free((void *)addr);
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}
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}
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void page_free(void *addr) {
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if (addr == NULL) return;
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struct Page *p = (struct Page *)addr;
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p->next = free_list;
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free_list = p;
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}
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