Load transient U-boot and OpenSBI for a **single** power cycle

[jarkkojs]

I wonder if it would be possible to support https:/keystone-enclave/keystone/tree/master/sm extension? Given that Vision Quest 2 has PMP support it would be cheap platform to innovate in the field of confidential computing.

[jarkkojs]

Hey, so the more generic problem is this. It is indeed possible to flash custom U-boot and OpenSBI with e.g. re-configuring UARTS, using tftp or flashcp.

The more generic problem: is there a way to load transient U-boot.bin and OpenSBI for a one single power cycle:

Here's what I wrote to the issue at Keystone repository:

"All of the methods are sub-optimal in the sense that they require re-flash u-boot and/or opensbi. Optimal (for development) would be a method, where for a single power-cycle (boot), one could put the system live with custom images without flashing. Of course, they would be gone after power down, but that is kind of the point.

Maybe this would be a good issue for Starfiv VisionFive 2 repository as it is a generic problem spanning for any low-level experiementation with the SBC in the discussion."

See: keystone-enclave/keystone#339