Setting boot verbosity in the kernel config

[Stephen Borrill <netbsd%precedence.co.uk@localhost>]

In an embedded or customer-facing product, we don't want the kernel 
autoconf messages welcoming them. That's what boot -z is aim at. Due to 
incomplete aprint_* conversion, it's currently less than successful, but 
that's not my problem here (I use a local hack that basically makes 
printf() a copy of aprint_normal()).

I want to be able to set the boot verbosity in the kernel configuration 
and not have to hack the bootloader to pass the appropriate boot flags.
I also want the option to go back to normal or verbose mode from the 
bootloader if I wish.

So I've created a patch which provides something like:
options         BOOT_VERBOSITY="AB_SILENT"

The option is ORed with boothowto. It adds a AB_FORCENORMAL flag too which 
clears boothowto first. This can be used in both the kernel config and 
access with a new -n flag in the boot loader.

This means you can use BOOT_VERBOSITY="AB_SILENT" and then go back to 
normal with boot -n. Or if you want to stop the bootloader overriding it 
at all you can use BOOT_VERBOSITY="AB_SILENT|AB_FORCENORMAL".

The patch is here:

ftp://ftp.netbsd.org/pub/NetBSD/misc/sborrill/bootverb.patch

It's incomplete in that I've not updated the usage() text in the various 
bootloaders that use it to reflect the new flag.

--
Stephen