Compiling for thumb2
 

So, I've setup scratchbox by following the instructions posted here:
http://wiki.maemo.org/CSSU-thumb_too...cc4.7.2-linaro)

How do I determine if my application is in fact compiled for thumb2? Any way to tell based on the executable produced or libraries linked? I am passing -mthumb.

I ask this because compiling atari800 v3.0.0 makes the executable about 50k bigger with thumb/gcc4.72-linaro, so I wonder if I have everything right or not. It does seem to make the emulator a bit faster (about 5% based on some quick and dirty tests).

Re: Compiling for thumb2
 

Use readelf -A $BINARY , if it is thumb2 compiled you'll see "Tag_THUMB_ISA_use: Thumb-2"

Did you strip the binary before comparing the sizes? as gcc 4.7.2 produces more debug info than 4.2.1. Could you post all gcc options?

Re: Compiling for thumb2
 

Thanks, the binary is thumb2 compiled so that's at least working. The binary is stripped (I ran strip on it), so this size is after it's stripped.

I used a few different options to see how they affect the end result. What I think happened, is that in the GCC472 target, the configure script created a slightly different setup, as the libraries each is linked to is slightly different. I'll look into that and try to sort it out.

What options do you suggest using? I did try the options from the wiki page, -mthumb -mfpu=neon -ftree-vectorize -fgraphite and even just -mthumb, they pretty much created the same size executable for me and didn't seem to have much effect on the execution of this app. Oh, and -O3.

Just found this page:
http://boards.openpandora.org/index....ery-toolchain/

What do you think of the suggestions there? The Pandora is similar hardware to the n900 (IIRC) Specifically, this "-mcpu=cortex-a8" which webpages I've looked at seem to suggest might help produce code specifically tuned for our CPU. Also, it seems from the reading I've done, that just passing -mfpu=neon may not be enough to enable neon optimizations due to unsafe math functions (??)

Another page about FP on the A8:
http://pandorawiki.org/Floating_Point_Optimization

Re: Compiling for thumb2
 

I just wanna tell you that I have had enough from this cssu thumb2

each time I have tried to install it on my n900 ended up reflashing it and for three days i have reflashed my device five times

Don't know what is wrong even though I have tried to follow instructions
and tried to upgrade the kenel

Re: Compiling for thumb2
 

It works fine, so if you're having trouble, it's something on your end. Maybe you should stick with CSSU stable or testing in that case.

Re: Compiling for thumb2
 

thanks for reply but i have cssu stable and and enabled cssu devel and cssu testing and cssu stable and extras-devel only

When the update came and strated updating either through x-terminal or through HAM after a reboot it get stucks and rebooting all the time

I have tried to install it several time and I have updated the kernel but no use

Even when I have tried to EMMC flash I couldn't only normal flash

So I don't know what Happen

Notice when i update the kernel it keeps showing unknown version in about products and *#0000# and health check so what i did I returned back to it's stock kernel to fix this problem

Re: Compiling for thumb2
 

why man
why you have enabled cssu-testings and cssu-devel repository when you have cssu-stable installed on your n900
please disable them and read twice or thrice wiki pages
please post your problem in cssu-testings or stable thread
there you will assisted what to do

Re: Compiling for thumb2
 

thanks dude for the information