Tested in Bhyve by dropping to single user and deleting /boot/entropy.
```
Loading kernel...
/boot/test.GENERIC/kernel text=0x167d6a4 data=0x1fff04+0x61b9c4 syms=[0x8+0x1a80f8+0x8+0x169696]
Loading configured modules...
can't find '/boot/entropy'
...
Features2=0xfed83203<...,RDRAND,...>
...
random: registering fast source Intel Secure Key RNG
random: fast provider: "Intel Secure Key RNG"
random: unblocking device.
...
( no warning from __stack_chk_init )
```