kd> ub 0xffff
kbdclass!memcpy+0x71:
fffff800`7e3d32b1 75f0 jne kbdclass!memcpy+0x63 (fffff800`7e3d32a3)
fffff800`7e3d32b3 c3 ret
fffff800`7e3d32b4 666666660f1f840000000000 nop word ptr [rax+rax]
fffff800`7e3d32c0 4e8d1c02 lea r11,[rdx+r8]
fffff800`7e3d32c4 482bd1 sub rdx,rcx
fffff800`7e3d32c7 7309 jae kbdclass!memcpy+0x92 (fffff800`7e3d32d2)
fffff800`7e3d32c9 4c3bd9 cmp r11,rcx
fffff800`7e3d32cc 0f876e010000 ja kbdclass!memcpy+0x200 (fffff800`7e3d3440)