From: greg@kroah.com (Greg KH)
To: kernelnewbies@lists.kernelnewbies.org
Subject: How to compile Linux kernel with -O0 flag
Date: Sat, 13 Aug 2016 20:35:34 +0200 [thread overview]
Message-ID: <20160813183534.GA22784@kroah.com> (raw)
In-Reply-To: <20160813211516.7a8dace1@e733>
On Sat, Aug 13, 2016 at 09:15:16PM +0300, Aleksander Alekseev wrote:
> Hello
>
> I'm currently exploring different ways of debugging Linux kernel. And I
> noticed that for many variables gdb displays <optimized out>. Also from
> experience of debugging ring3 code I know that sometimes debugger may
> act crazy unless -O0 was used.
>
> Apparently there is no corresponding option in `make menuconfig`. So
> how do you solve this problem? Just `CFLAGS=-O0 make ...` or somehow
> else? I wonder what is the "right" way of doing it because you know,
> it's a kernel, it can accidentally break something unless you are
> careful :)
The kernel will not run with -O0, sorry, just live with the build
optimization levels that is currently used and you should be fine.
But why do you want to use a debugger on the kernel? That's not a
normal task unless you are bringing up a new hardware platform.
best of luck,
greg k-h
next prev parent reply other threads:[~2016-08-13 18:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-13 18:15 How to compile Linux kernel with -O0 flag Aleksander Alekseev
2016-08-13 18:35 ` Greg KH [this message]
2016-08-13 18:56 ` Aleksander Alekseev
2016-08-13 19:12 ` Greg KH
2016-08-13 19:15 ` Mike Krinkin
2016-08-14 11:11 ` Hao Lee
2016-08-14 11:31 ` Greg KH
2016-08-14 12:05 ` Hao Lee
2016-08-14 14:20 ` Yann Droneaud
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