optimization levels in genode

[Stefan Kalkowski]

Hi,

On Thu, Nov 01, 2018 at 08:36:20PM +0800, lzSun wrote:
> Hello,
> I find in repos/base/mk/global.mk, there's a default optimization level which is -O2. When I change this flag to -O3 or -Ofast , the system can't booting ,which stuck at " Starting kernel ...  ". I wonder how can I fix this problem and I am now building and run Genode 18.05 with trustzone for hw_imx53_qsb_tz platform. I am looking forward for your reply, thank you very much! 

did you followed my advice to first enable the FPU in the kernel?
Otherwise it is totally clear to not work at all, because -O3 compiled
code make heavily use of the FPU.

I've compiled a hard-float compiler like advised to you, took that
topic branch, and recognized that for the i.MX53 one needs to set the
-mfpu flag to neon. Then I could measure the performance gain on the
i.MX53 Quickstart board. I've updated my topic branch to be
ready-to-merge, and prepared a topic branch that uses hard-float neon
FPU at least on i.MX53 here:

  https://github.com/skalk/genode/tree/imx53-hf-neon

Regards
Stefan

> 
> 
> ------------------
> Best wishes

> _______________________________________________
> Genode users mailing list
> users at lists.genode.org
> https://lists.genode.org/listinfo/users


-- 
Stefan Kalkowski
Genode labs

https://github.com.skalk | https://genode.org