43 lines
1.0 KiB
C
43 lines
1.0 KiB
C
#include <mm/pmm.h>
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#include <lib/rand.h>
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#include <lib/print.h>
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void pmm_randomise_memory(void) {
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print("pmm: Randomising memory contents...");
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for (size_t i = 0; i < memmap_entries; i++) {
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if (memmap[i].type != MEMMAP_USABLE)
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continue;
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#if defined (BIOS)
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// We're not going to randomise memory above 4GiB from protected mode,
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// are we?
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if (memmap[i].base >= 0x100000000) {
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continue;
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}
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#endif
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uint8_t *ptr = (void *)(uintptr_t)memmap[i].base;
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size_t len = memmap[i].length;
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for (size_t j = 0;;) {
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uint32_t random = rand32();
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uint8_t *rnd_data = (void *)&random;
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if (j >= len)
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break;
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ptr[j++] = rnd_data[0];
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if (j >= len)
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break;
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ptr[j++] = rnd_data[1];
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if (j >= len)
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break;
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ptr[j++] = rnd_data[2];
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if (j >= len)
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break;
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ptr[j++] = rnd_data[3];
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}
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}
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print("\n");
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}
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