28 lines
894 B
C
28 lines
894 B
C
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#include <socks/libc/string.h>
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#include <socks/machine/_gdt.h>
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static void init_entry(struct gdt_entry *entry, int access, int flags)
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{
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entry->ge_limit_low = 0xFFFF;
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entry->ge_base_low = 0x00;
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entry->ge_base_mid = 0x00;
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entry->ge_access = access;
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entry->ge_gran = flags;
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entry->ge_base_hi = 0x00;
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}
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int gdt_init(struct gdt *gdt, struct gdt_ptr *gdtp)
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{
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memset(&gdt->g_entries[0], 0x0, sizeof gdt->g_entries[0]);
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init_entry(&gdt->g_entries[1], GDT_A_PRESENT | GDT_A_CODEREAD | GDT_A_CODE, GDT_F_64BIT);
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init_entry(&gdt->g_entries[2], GDT_A_PRESENT | GDT_A_DATAWRITE | GDT_A_DATA, GDT_F_64BIT);
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init_entry(&gdt->g_entries[3], GDT_A_PRESENT | GDT_A_USER | GDT_A_CODEREAD | GDT_A_CODE, GDT_F_64BIT);
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init_entry(&gdt->g_entries[4], GDT_A_PRESENT | GDT_A_USER | GDT_A_DATAWRITE | GDT_A_DATA, GDT_F_64BIT);
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gdtp->g_ptr = (uint64_t)gdt;
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gdtp->g_limit = sizeof(*gdt) - 1;
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return 0;
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}
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