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I would like to read a brief review of OpenSBI functions, or a rather minimum required set to get Linux like OS to run. How much Linux kernel depends on supervi
by ruslan 3y ago
I would like to read a brief review of OpenSBI functions, or a rather minimum required set to get Linux like OS to run. How much Linux kernel depends on supervisor ? Also, worth pointing that there's U-Boot which also does some hardware initialization on which kernel relies on.
- Taniwha 3y agoUBoot typically runs in supervisor mode while OpenSBI runs in machine mode (as would OPTEE) - OpenSBI's (and OPTEE's) memory is locked behind a PMAP block so it can't be hacked from supervisor mode If your riscv core has hypervisor support that sits between machine mode and supervisor modes
- synergy20 3y agoisn's OpenSBI's S means 'supervisor' mode? so OpenSBI is supposed to be in supervisor mode?
- Taniwha 3y agoNope, it runs in machine mode (I've ported it) - the S does stand for Supervisor, but I guess that's because it supervises the system
- brucehoult 3y agoSBI is the ABI for the Supervisor to call to get certain services that can't be done in S mode.
- snvzz 3y agoThe SBI spec[0] is not a long read. 0. https://github.com/riscv-non-isa/riscv-sbi-doc/releases https://github.com/riscv-non-isa/riscv-sbi-doc/releases