LOADIWKEY

if not cr4 >> 19 & 1:            # CR4.KL; clear without Key Locker
    fault(UD)
if cr0 >> 2 & 1 or not cr4 >> 9 & 1:
    fault(UD)                    # CR0.EM set, CR4.OSFXSR clear
if cr0 >> 3 & 1:
    fault(NM)                    # CR0.TS
if CPL > 0:
    fault(GP, 0)
c = eax                          # bit 0 NoBackup, 4:1 KeySource
ks = c >> 1 & 0xF
has = cpuid_leaf(0x19, 0)[2]     # bit 0: NoBackup; 1: KeySource 1
if ks > 1 or c >> 5:
    fault(GP, 0)                 # reserved
if c & 1 and not has & 1:
    fault(GP, 0)
if ks == 1 and not has >> 1 & 1:
    fault(GP, 0)
k = xmm[0] << 256 | src1 << 128 | src2
                                 # the integrity key, from XMM0, and
                                 # the encryption key, from the two
ok = 1
if ks == 1:                      # KeySource 1: mixed with random
    ok = seed_ready()            # bits of RDSEED's source, so that
    if ok:                       # not even CPL 0 knows the key
        k = k ^ seed(384)
if ok:
    iwkey = k | (c & 0x1F) << 384
zf = 1 - ok                      # no random bits ready: IWKey kept
of = sf = af = pf = cf = 0