Hi, again---I thought we were switching h/w platforms, but it turns out we'll be sticking with this system for a bit longer.
> I am guessing its some sort of Tegra CPU which had FPU but no neon > unit... Right, it's a Tegra 2 T20, which lacks the NEON extension. > we dont have default tunes available readily that are good for tegra > but its not hard to create one Erm. :-% I guess 'hard' is relative. Could you provide an extra hint about this? Do you mean I should make a copy of 'tune-cortexa9.inc' and change DEFAULTTUNE from 'cortexa9-neon' to 'cortexa9'? Or, is there a way to include the existing file and override the default? Also, I'm not sure what do to with the 'VFP Tunes'. I found this thread - http://www.mail-archive.com/[email protected]/msg09497.html which seems to talk about some of these issues. I think I need to add '-mfpu=vfpv3-d16' to the compiler flags, but, as this is the first 'real' thing I've tried to do with bitbake, I'm unsure how to accomplish this... On Fri, Aug 31, 2012 at 7:00 PM, Khem Raj <[email protected]> wrote: > Hi Evade, > > Glad it worked for you at first go. Thats quite an achievement for yocto > > On Fri, Aug 31, 2012 at 2:58 PM, Evade Flow <[email protected]> wrote: >> >> Now I'm wondering: is there any easy way to optimize for the actual >> target(s) a bit more than the qemuarm MACHINE type does? The example >> Makefiles for the old project all contain this line: >> >> CFLAGS = -g -mcpu=arm1136jf-s -O2 -pipe >> >> What's the best way to arrange for that '-mcpu' option to be used by all >> recipes? Also, are there other optimizations I should consider? I'm >> appending some details about the board in question, as well as the >> complete output from booting it to a prompt. I'd be ever so grateful if >> someone could recommend sensible base settings for this system, and >> explain how to create a Poky 'layer', or 'machine'---or whatever the >> right nomenclature is---to apply these settings. >> >> Sorry for the long post, and thanks in advance for any advice! >> >> >> ---------- >> >> ~ # uname -a >> Linux localhost 2.6.36.2-WR3.0.2ax_standard #1 SMP PREEMPT Wed Oct 19 >> 21:58:54 >> EEST 2011 armv7l armv7l armv7l GNU/Linux ODBP D1.0.1 (10.11.2011) >> >> ~ # cat /proc/cpuinfo >> Processor : ARMv7 Processor rev 0 (v7l) >> processor : 0 >> BogoMIPS : 1795.68 >> >> Features : swp half thumb fastmult vfp edsp vfpv3 vfpv3d16 > > > I am guessing its some sort of Tegra CPU which had FPU but no neon unit > there is rich set of tuning available for arm. > > So you would create configuration file for your machine. May be just > start by making a copy of > qemuarm.conf > > then you would select the right tuning > > require conf/machine/include/tune-arm926ejs.inc currently select arm926 > you might want something more appropriate. > > add > conf/machine/include/tune-arm1136jf-s.inc > > this will get to what you had in old project > > and you can also go a step further and make it more appropriate for > tegra cpu that you have > we dont have default tunes available readily that are good for tegra > but its not hard to create one > > Look at > > e.g on tune-cortexa9.inc > > you would create something similar for your cpu and then select proper > default tunings. > > Have fun > > -Khem _______________________________________________ yocto mailing list [email protected] https://lists.yoctoproject.org/listinfo/yocto
