> -----Original Message----- > From: Rob Herring [mailto:[email protected]] > Sent: Thursday, May 31, 2018 6:09 AM > To: Udit Kumar <[email protected]> > Cc: Architecture Mailman List <[email protected]>; > [email protected]; [email protected] > Subject: Re: Issue#9 Document hardware need (if any)
> > I meant, what hardware features a SOC must have to run EBBR. > > This include IPs/CPU architecture etc. > > NAND/USB could be optional, this is not must for EBBR. > > EBBR is about what the distros need/want. Raw NAND is never going to be > supported by distros (in their installers, you can always manually craft > images for > NAND). USB is maybe too specific (though SD card is really the only other > choice), but there needs to be either some removable media or network boot > (or perhaps we can say both) for an OS installer and then there must be a > block > device to install to. That's one usecase. The 2nd is that you create an OS > image > offline and put the image on either a USB MS device or SD card. So that is > just a > subset of the first (unless the first only supports net boot). Thanks. This fair to put this hardware requirement, which is needed by distros . > >> >> I think being explicit with h/w requirements implied by UEFI would > >> >> be a good thing. If I'm designing a board, I don't want to have to > >> >> sort thru UEFI specs to distill down a bullet list of h/w reqs. > >> > > >> > I like to cover here, all on/off chip components could be > >> > IP/peripherals needed > >> for EBBR. > >> > Like if USB is present, minimum version of xchi or echi needs to be > >> > supported > >> by hardware. > >> > >> One look at XHCI or EHCI drivers and the variations across SoCs will > >> tell you that just specifying those specs is pointless. But it is > >> probably worth saying something about USB. Perhaps saying USB host > >> port(s) (more than 1?) required and the firmware must support booting > >> from USB. > > > > I put USB as an example. > > Please refer SBSA, which mandate the version of ECHI/XCHI > > As Grant said, SBSA has a different focus. IMO, it has the same issue I > mentioned > though. Just look at the mess the SBSA uart is. > > > should be supported. Also this specify other IPs too like Timer, UART, > > GiC etc > > > > IMO, such strict hardware requirement for EBBR will not be useful. > > Agreed. We'd be kidding ourselves that we have any say in the SoC design. > > Rob _______________________________________________ boot-architecture mailing list [email protected] https://lists.linaro.org/mailman/listinfo/boot-architecture
