GPIO supported devices
Hi, Which of the following devices actually have gpio working with OpenBSD-ARM64 or ARMv7 platform. I have done alot with the RPI's but gpio doesn't work there. I need to control external devices for machine control. I understand security is in OpenBSD priority list but maybe there is a specific device that currently works with GPIO. any pointers to this is highly appreciated.
Re: GPIO supported devices
> From: Kihaguru Gathura > Date: Fri, 21 Jun 2019 12:41:35 +0300 > > Hi, > > Which of the following devices actually have gpio working with > OpenBSD-ARM64 or ARMv7 platform. > > I have done alot with the RPI's but gpio doesn't work there. I need to > control external devices for machine control. > > I understand security is in OpenBSD priority list but maybe there is a > specific device that currently works with GPIO. any pointers to this > is highly appreciated. Boards with Allwinner "sunxi" SoCs have working gpio(4) support, where there is more or less proper protection against accidentally configuring and using gpio pins that are actually in use by other devices. There are both ARMv7 and ARMv8 variants, but you're probably better off picking a board based on the Allwinner A64 as OpenBSD/arm64 sees more development than OpenBSD/armv7. Currently OpenBSD/armv7 does not support SMP for example. Probably best to avoid the Allwinner H5 for now as we have seen stability issues with various H5 boards. The NanoPi A64 board is attractively priced, but the the onboard WiFi chip isn't supported. The Pine64 Pine A64 boards are also a reasonable choice.
ROCKPro64 firmware
I've finally managed to build a properly working (and fully open source) firmware for the ROCKPro64. The firmware consists of two files, which can be downloaded from: https://sibelius.home.xs4all.nl/firmware/rk3399-rockpro64/idbloader.img https://sibelius.home.xs4all.nl/firmware/rk3399-rockpro64/u-boot.itb In order to use this firmware you'll have to write it to a uSD card or an eMMC module with the following commands: # dd if=idbloader.img of=/dev/sdXc seek=64 # dd if=u-boot.itb of=/dev/sdXc seek=16384 Note that if you flashed a firmware to the onboard SPI flash, you'll have to erase it first or disable the SPI flash with a jumper wire connecting pins 23 and 25. Also note that the firmware overlaps with the msdos partition in the default OpenBSD/arm64 disk layout. Therefore you can't have the firmware and the OpenBSD boot/root filesystems on the same device without running through additional hoops. Ultimately the goal is to make it possible to put this firmware in SPI flash, but I haven't looked into that yet. This firmware uses a more standard serial speed of 115200, which means you can use almost any USB TTL serial cable. DVFS is supported so you can use sysctl hw.setperf to control to clock speed of the CPUs. But be aware that without a fan the board will probably overheat if you run it at the highest supported clock speed. At some point this should land in the official u-boot-aarch64 packages. But since this build relies on a fairly large patch set that hasn't landed upstream yet, this may take some time. Cheers, Mark
