Hello Anup,
I have looking at you OpenSBI code firmware/payloads/test_head.S. Here like in U-Boot's common/spl/spl_opensbi.c you put all but one hart in to an enless loop (hang).
When Linux boots via UEFI it will wake up the extra harts after ExitBootServices(). So I assume we should define function hang() in lib/hang.c as __efi_runtime to avoid seeing it overwritten by the EFI payload.
@Ard: Does Linux take care of the hanging harts and redirect them to its own routine before SetVirtualAddressMap()? Otherwise anything could happen.
On the Kendryte K210 we don't have SPL. So we will not boot in the sequence SPL->OpenSBI->U-Boot but OpenSBI->U-Boot. Does this imply that we have to implement the hart lottery at the entry point of main U-Boot in this case?
Best regards
Heinrich