Custom kernel for RPi2 and 3

[George Rosamond]

bob prohaska:
> On Wed, Feb 21, 2018 at 09:16:52AM -0700, Ian Lepore wrote:
>> On Wed, 2018-02-21 at 05:44 +0000, George Rosamond wrote:
>>> bob prohaska:
>>>>
>>>> [...]
>>> Bob:
>>>
>>> This script can generate an /etc/src.conf based on the running system,
>>> extracted from /etc/src.conf(5). Since there's no standard /etc/src.conf
>>> through FreeBSD versions, it's a hassle to maintain without it.
>>>
>>> http://wiki.torbsd.org/doku.php?id=en:a_shell_script_to_convert_src.conf_5_contents_to_an_example_etc_src.conf_file
>>>
>>> HTH
>>
>> That script looks like a really complicated way to do:
>>
>> ? make showconfig __MAKE_CONF=/dev/null SRCCONF=/dev/null
>>
>> -- Ian
> 
> Is there a straightforward way to sort what's being used from what
> can't (or isn't) being used? For example, on a Pi2 the command emits
> MK_WIRELESS      = yes
> MK_WIRELESS_SUPPORT = yes
> Given that there's no onboard wireless and no USB WiFi adapter, it's
> fairly obvious those two can be set to "no". It's less clear what 
> MK_TEXTPROC      = yes
> portends, and whether it's essential.
> 
> Perhaps I mis-posed the original question. What I'm looking for might
> better be called a minimal kernel configuration supporting only the
> hardware native to a particular board. The old RPI2 kernel config file
> seemed to do that, but I gather it's deprecated. 

AFAIK, there's never been a simple way to compare GENERIC to the
hardware in any easy way.  In years past, I spent the time going
line-by-line and trying to tinker with it. And the expansion of
FreeBSD's abilities have added a lot of weight to the kernel.

But I can imagine a script that takes GENERIC, filters what is in dmesg
and what is vital to boot, then gives dumps out a working, smaller
custom GENERIC.

Maybe Ian sees something in /usr/src/Makefile that I missed again :)

g