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Subject: Re: Recommended way to do kernel-development for static modules
To:     Ajay Garg <ajaygargnsit@gmail.com>, linux-kernel@vger.kernel.org,
        linux-pci@vger.kernel.org
References: <CAHP4M8V6b-su=bpM-qMg5pnDKfvh-Ks_3bFfeK7p4hA2RqQw+Q@mail.gmail.com>
From:   Randy Dunlap <rdunlap@infradead.org>
Message-ID: <a4471053-a4e3-42ac-6177-056bfe371c70@infradead.org>
Date:   Fri, 1 Oct 2021 21:33:05 -0700
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On 10/1/21 8:31 PM, Ajay Garg wrote:
> Hello All,
> 
> Let's say, I want to make a simple printk change to drivers/pci/bus.c,
> compile it, load it, test it.
> 
> Now, since bus.o is built as a result of CONFIG_PCI=y in
> drivers/pci/Makefile, so this module is statically built, and as a
> result doing a "make M=drivers/pci" does-not-pick-up-the-change /
> have-any-effect.
> 
> Doing a simple "make" takes too long, everytime for even a trivial change.
> 
> 
> So, what is the recommended way to do kernel-development for static modules?
> 
> 
> Will be grateful for pointers.

Just to build drivers/pci/bus.o, you do
$ make drivers/pci/bus.o

That will tell you if you have any build errors/warnings.

For run-time testing, AFAIK you don't have any choice but to
build a full kernel and boot it.

-- 
~Randy