Hi Arnd,

[...]

A common pattern these days is to do dependencies like

arch/*/Kconfig:
	config ARCH_FOO
	bool "Enable support for Foo platform"
	help
	  ...


drivers/*/Kconfig
	config SUBSYS_FOO
	bool "SUBSYS driver for Foo"
	depends on ARCH_FOO || COMPILE_TEST
	depends on OF && REGULATOR && GENERIC_PHY # or whatever

Russell's comments w.r.t. Kconfig warnings when config names change
still holds regardless of select vs depends on.

That way we can enable everything in the defconfig, but someone
who likes to build a more specialized kernel can disable the
other platforms and won't get the drivers that are specific to
those.

I personally think this is a bit more verbose than what we need, but
I don't strongly object doing it that way.

You'd still be able to do this without ARCH_FOO, though you would need
to know which drivers are necessary for a particular SoC. That seems to
be the way things are handled on x86; I don't recall having to select
support for specific machines there, just the individual drivers.

The code size really should not matter much on ARM64 though: it's
unlikely we will see a lot of systems with less than a few gigabytes
of memory, and I expect that a generic kernel would be e.g. 6 MB
instead of 4 MB for a platform specific kernel.

Agreed. If there kernel size begins looking unwieldy we either need to
be compiling more things as modules or a more drastic kernel weight loss
program.

Mark.