// 16 bit code segment base=0xf0000 limit=0xffff (SEG32_MODE16_CS)
GDT_LIMIT(BUILD_BIOS_SIZE-1) | GDT_CODE | GDT_BASE(BUILD_BIOS_ADDR),
// 16 bit data segment base=0x0 limit=0xffff (SEG32_MODE16_DS)
GDT_LIMIT(0x0ffff) | GDT_DATA,
// 16 bit code segment base=0xf0000 limit=0xffff (SEG32_MODE16_CS)
GDT_LIMIT(BUILD_BIOS_SIZE-1) | GDT_CODE | GDT_BASE(BUILD_BIOS_ADDR),
// 16 bit data segment base=0x0 limit=0xffff (SEG32_MODE16_DS)
GDT_LIMIT(0x0ffff) | GDT_DATA,