30 lines
743 B
C
30 lines
743 B
C
#include "gdt.h"
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void encode_gdt_entry(unsigned short int * target, struct GDT source) {
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if((source.limit > 65536) && ((source.limit & 0xFFF) != 0xFFF)) {
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/* This needs to error out. */
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return;
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}
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if(source.limit > 65536) {
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/* Granularity adjustments */
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source.limit = source.limit >> 12;
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target[6] = 0xC0;
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}
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else {
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target[6] = 0x40;
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}
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/* Encode limit */
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target[0] = source.limit & 0xFF;
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target[1] = (source.limit >> 8) & 0xFF;
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target[6] |= (source.limit >> 16) & 0xF;
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/* Encode base */
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target[2] = source.base & 0xFF;
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target[3] = (source.base >> 8) & 0xFF;
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target[4] = (source.base >> 16) & 0xFF;
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target[7] = (source.base >> 24) & 0xFF;
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/* Encode type */
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target[5] = source.type;
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} |