Hi Chris, CC DT On Thu, May 19, 2022 at 4:37 PM Chris Down <chris@xxxxxxxxxxxxxx> wrote: > Geert Uytterhoeven writes: > >All of the above options are appropriate for "classic" systems, > >where the console device is selected using the "console=" option. > > > >On systems using Device tree, the serial console device is selected > >using the "chosen/stout-path" property in DT, and the graphical > >console is usually auto-detected and auto-enabled through DRM. > >Do you envision a way to specify a specific console loglevel on the > >kernel command line on such systems? > > Interesting question! I hadn't really thought about device tree. I actually > have very little understanding of how it works to be honest :-) > > I'm happy to add loglevel support to device tree, I assume I'd add another > property under the chosen node, like chosen/stdout-loglevel. Please do not add a new property there. IMHO, the loglevel should be specified on the kernel command line, and not be fixed using a DT property. Typically, boot loaders (e.g. U-Boot) replace the command line specified in chosen/stdout-path in DT by something retrieved from the boot environment (e.g. user-specifief bootargs in NVMEM). > I have some questions, though: > > 1. It looks like DT is standardised. Do I need to get standards approval first? > 2. Is there documentation on how to reliably test DT changes? The DT specification can be found at https://www.devicetree.org/specifications/ Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
