On Tue, Apr 20, 2021 at 07:22:47AM +0100, Stuart Henderson wrote: > On 2021/04/20 00:46, Alessandro Pistocchi wrote: > > Hi, > > > > I am playing around with openbsd kernel source code on a raspberry pi 4. > > > > I have a couple of questions: > > Does openbsd use low or high peripheral mode? > > At what virtual address does openbsd map the peripheral base address ? > > > > I had a look at the source code but that part is still a bit cryptic for me. > > > > Thank you, > > Alessandro > > I can give you some pointers that will give you some places to start > digging, but not answer everything: > > https://github.com/raspberrypi/firmware/issues/1374#issuecomment-617628570 > suggests that this must be set by the video controller (which is used to > boot the main CPU), and that it's done automatically on newer firmware > depending on the device tree used. > > You can display the device tree used with "eeprom -p". > > If you're using U-Boot (included for rpi4 on recent snapshots/images) > then the device trees are provided by OpenBSD and currently come from > Linux 5.11 (via the sysutils/dtb port) where it looks like they're low.
The device trees supplied with the raspberry pi firmware are used on raspberry pi, not the device trees included in U-Boot or linux. These are packaged as sysutils/raspberrypi-firmware and come from https://github.com/raspberrypi/firmware/tree/master/boot > > If you're using the UEFI firmware then the device trees are supplied > with it, I haven't checked but I guess those are probably low too. > > >
