per-device sysctls

[M. Warner Losh]

In message: <2468.1077825069 at critter.freebsd.dk>
            "Poul-Henning Kamp" <phk at phk.freebsd.dk> writes:
: In message <xzpbrnllnj6.fsf at dwp.des.no>, Dag-Erling =?iso-8859-1?q?Sm=F8rgrav?=
:  writes:
: 
: >BTW, the dev tree on my laptop looks like this:
: >
: >des at des ~% sysctl dev
: >dev.nexus0.npx0.%class: npx
: >dev.nexus0.npx0.%desc: math processor
: >dev.nexus0.npx0.%driver: npx
: >dev.nexus0.acpi0.acpi_timer0.%class: acpi_timer
: >dev.nexus0.acpi0.acpi_timer0.%desc: 24-bit timer at 3.579545MHz
: >dev.nexus0.acpi0.acpi_timer0.%driver: acpi_timer
: 
: Just for the record:  Having based this on newbus it only documents
: hardware-anchored device drivers.  I don't know if this is going to
: be a limitation we will have to address or not, but I think you should
: reserve the toplevel name "pseudo" or "sw" or similar as a placeholder
: for non-hardware device drivers, just in case.

There's not really a tree for pseudo devices right now.  They just are
kludged into the system any old way that they can be at the moment.
They aren't part of the hardware device hierarchy.

Warner