[13:02] <ikonia> how can I validate the GIO config for i2c and spi 
[13:03] <ikonia> just moved my little dev project to ubuntu and before I start dealing with the many failures, I want to make sure the basics are right
[13:03] <ikonia> waveform I apprecaite what you said about raspi-config, so I'm not messing with that at this stage
[13:07] <ikonia> I assume /boot/config.txt is supported with ubuntu 20.04 (I think someone confirmed this last time I asked) 
[13:08] <ikonia> (it looks like it's in /boot/firmware/config,txt) 
[13:16] <waveform> ikonia, yup -- the location on ubuntu is /boot/firmware/config.txt because that's where we mount the boot partition. The one thing to be aware of is that, up to (and including) focal (20.04) u-boot is *also* in the boot sequence so config.txt configures the raspberry pi bootloader, but it *doesn't* configure things like the kernel command line because it's just loading u-boot which then takes over and handles loading the kernel, constructing the 
[13:16] <waveform> kernel command line etc. From groovy (20.10) onwards the ubuntu boot sequence is much more "traditional" (at least for pis) using just the pi bootloader
[13:18] <waveform> as for how you can tell I2C and SPI are loaded -- if /dev/spidev0.* is present then spi=on is active in the base overlay. Likewise if /dev/i2c-1 is present, then i2c_arm=on is active in the base overlay (those devices won't appear otherwise)
[13:20] <ikonia> thanks waveform