Hi Rob, thanks for having a look at this. On Tue, 2020-12-15 at 13:54 -0600, Rob Herring wrote: > On Tue, Dec 15, 2020 at 1:01 PM Nicolas Saenz Julienne > wrote: > > > > Hi Catalin, > > > > On Tue, 2020-12-15 at 18:44 +0000, Catalin Marinas wrote: > > > On Tue, Dec 15, 2020 at 04:56:20PM +0100, Nicolas Saenz Julienne wrote: > > > > Soon to be released versions of RPi4's firmware will take of care > > > > passing their bootloader's configuration to the OS by copying it into > > > > memory and creating a reserved memory node in the board's DT. In order > > > > to make use of this information, this series introduces a new generic > > > > nvmem driver that maps reserved-memory nodes into nvmem devices. > > > > > > > > An alternative approach, less nice IMO, would be to create a > > > > platform-specific 'soc' driver. > > > > > > What kind of information is this and how would the kernel use it? > > > > Sorry, I wasn't clear enough, the ultimate goal is to use this information from > > user-space, through nvmem's sysfs interface. The kernel itself has no use for > > it. > > That still leaves the first question. It's the bootloader configuration, stuff like boot order, TFTP IP, etc... See more here: https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_bootloader_config.md I'll add a new paragraph explaining all this on next version's cover letter. Regards, Nicolas