// First entry can't be used.
0x0000000000000000LL,
// 32 bit flat code segment (SEG32_MODE32_CS)
- 0x00cf9b000000ffffLL,
+ GDT_LIMIT(0xfffff) | GDT_CODE | GDT_B | GDT_G,
// 32 bit flat data segment (SEG32_MODE32_DS)
- 0x00cf93000000ffffLL,
+ GDT_LIMIT(0xfffff) | GDT_DATA | GDT_B | GDT_G,
// 16 bit code segment base=0xf0000 limit=0xffff (SEG32_MODE16_CS)
- 0x00009b0f0000ffffLL,
+ GDT_LIMIT(0x0ffff) | GDT_CODE | GDT_BASE(0xf0000),
// 16 bit data segment base=0x0 limit=0xffff (SEG32_MODE16_DS)
- 0x000093000000ffffLL,
+ GDT_LIMIT(0x0ffff) | GDT_DATA,
// 16 bit code segment base=0 limit=0xffffffff (SEG32_MODE16BIG_CS)
- 0x008f9b000000ffffLL,
+ GDT_LIMIT(0xfffff) | GDT_CODE | GDT_G,
// 16 bit data segment base=0 limit=0xffffffff (SEG32_MODE16BIG_DS)
- 0x008f93000000ffffLL,
+ GDT_LIMIT(0xfffff) | GDT_DATA | GDT_G,
};
// GDT descriptor
// 20..27 CS zeros filled in by BIOS
// 28..2f SS zeros filled in by BIOS
- //es:si
- //eeee0
- //0ssss
- //-----
-
// check for access rights of source & dest here
// Initialize GDT descriptor
- SET_SEG(ES, regs->es);
- u16 si = regs->si;
- u16 base15_00 = (regs->es << 4) + si;
- u16 base23_16 = regs->es >> 12;
- if (base15_00 < (u16)(regs->es<<4))
- base23_16++;
- SET_VAR(ES, *(u16*)(si+0x08+0), 47); // limit 15:00 = 6 * 8bytes/descriptor
- SET_VAR(ES, *(u16*)(si+0x08+2), base15_00);// base 15:00
- SET_VAR(ES, *(u8 *)(si+0x08+4), base23_16);// base 23:16
- SET_VAR(ES, *(u8 *)(si+0x08+5), 0x93); // access
- SET_VAR(ES, *(u16*)(si+0x08+6), 0x0000); // base 31:24/reserved/limit 19:16
-
+ u32 si = regs->si;
+ u64 *gdt_far = (void*)si;
+ u16 gdt_seg = regs->es;
+ u32 loc = (u32)MAKE_FLATPTR(gdt_seg, gdt_far);
+ SET_FARVAR(gdt_seg, gdt_far[1], GDT_DATA | GDT_LIMIT((6*sizeof(u64))-1)
+ | GDT_BASE(loc));
// Initialize CS descriptor
- SET_VAR(ES, *(u16*)(si+0x20+0), 0xffff);// limit 15:00 = normal 64K limit
- SET_VAR(ES, *(u16*)(si+0x20+2), 0x0000);// base 15:00
- SET_VAR(ES, *(u8 *)(si+0x20+4), 0x000f);// base 23:16
- SET_VAR(ES, *(u8 *)(si+0x20+5), 0x9b); // access
- SET_VAR(ES, *(u16*)(si+0x20+6), 0x0000);// base 31:24/reserved/limit 19:16
-
+ SET_FARVAR(gdt_seg, gdt_far[4], GDT_CODE | GDT_LIMIT(0x0ffff)
+ | GDT_BASE(0xf0000));
// Initialize SS descriptor
- u16 ss = GET_SEG(SS);
- base15_00 = ss << 4;
- base23_16 = ss >> 12;
- SET_VAR(ES, *(u16*)(si+0x28+0), 0xffff); // limit 15:00 = normal 64K limit
- SET_VAR(ES, *(u16*)(si+0x28+2), base15_00);// base 15:00
- SET_VAR(ES, *(u8 *)(si+0x28+4), base23_16);// base 23:16
- SET_VAR(ES, *(u8 *)(si+0x28+5), 0x93); // access
- SET_VAR(ES, *(u16*)(si+0x28+6), 0x0000); // base 31:24/reserved/limit 19:16
+ loc = (u32)MAKE_FLATPTR(GET_SEG(SS), 0);
+ SET_FARVAR(gdt_seg, gdt_far[5], GDT_DATA | GDT_LIMIT(0x0ffff)
+ | GDT_BASE(loc));
u16 count = regs->cx;
asm volatile(
// Load new descriptor tables
- "lgdtw %%es:0x8(%%si)\n"
+ "lgdtw %%es:(1<<3)(%%si)\n"
"lidtw %%cs:pmode_IDT_info\n"
// Enable protected mode
"movl %%eax, %%cr0\n"
// far jump to flush CPU queue after transition to protected mode
- "ljmpw $0x0020, $1f\n"
+ "ljmpw $(4<<3), $1f\n"
"1:\n"
// GDT points to valid descriptor table, now load DS, ES
- "movw $0x10, %%ax\n" // 010 000 = 2nd descriptor in table, TI=GDT, RPL=00
+ "movw $(2<<3), %%ax\n" // 2nd descriptor in table, TI=GDT, RPL=00
"movw %%ax, %%ds\n"
- "movw $0x18, %%ax\n" // 011 000 = 3rd descriptor in table, TI=GDT, RPL=00
+ "movw $(3<<3), %%ax\n" // 3rd descriptor in table, TI=GDT, RPL=00
"movw %%ax, %%es\n"
// move CX words from DS:SI to ES:DI