I am using an Allwinner H3 SoC (on a zeropi board) and I want to start up a secondary core without using an OS.
I am trying to use the SMC call CPU_ON, using the following code:

smc_call(0x84000003, 0x02, (void*)blink, 0);

Intel and AMD have added RDRAND a long time ago. IBM added the (awesomely named) DARN instruction to POWER9.

What do we have on AArch64? A mess. Ad-hoc drivers for specific RNGs, specified in device trees and (OMG) ACPI tables with device tree pieces…