porting linux in arm s3c2440 ,,,,plz help me

[ratul]

hi friends i am new to linux and i am trying to port linux 2.6 in s3c2440 ,,,,,,,,,,,
this is my project so plz help me with any information,,,,,,,,,

[Rubberman]

Which distribution+version are you trying to use? There are a number of distributions that already have been ported to the ARM processor family, including Debian. I am using Debian Etch with a 2.6.21 kernel on an ARM9 processor right now.

[ratul]

hi,,,,,i am using kernel version 2.6.30.4,,,,,,
actually i want to run some qt application on target
thats y i started with cross compilation,,,,,,,

the problem i am facing is in cross compilation,,, i am using tool chain of version 4.3.3
i extracted the tool chain and after dat i got two files opt and usr
i copied the 4.3.3 into /usr/local/arm

next i extracted "qt-embedded-linux-opensource-src-4.3.3"
after extraction i entered into the folder there was another folder named examples there i coppied my qt programs

then i went to examples.pro and i entered the folder names of my program in alphabatical order,,,,,,,

next i linked the qt-embedded with bin file
export PATH=$PATH:/usr/local/arm/4.3.3/bin

next i linked the present dirrectory
export QTDIR=$QTDIR:$PWD

next i linked the shared libraries
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$QTDIR/lib

next i followed
./configure -embedded arm -shared -no-cups

after cross compilation i ported the linux through hyper terminal,,,,,,
i transfered the "boot loader",,"kernel image",,,,,"root files"

after transfering the croos compiled progrms ,,,,the problem i got on board is floating point error,,,,,,,

i am stucking to this position plz reffer me wat changes i have to do

[Rubberman]

The Debian version I am using supports a full Xorg stack along with the usual GUI desktops and libraries, including Qt. You should be able to use a version of Debian with a newer kernel, or update the kernel yourself. I had no problem using the toolchain to build a new kernel on my CentOS system which is an X86_64 invironment.

[ratul]

hello can u plz clear my concept on soft-float,,,,,,,i am really not understanding

[Rubberman]

soft-float is software support for floating point operations which you would use unless your chip set also has hardware floating point. Example - the intel processor family (including Atom) have hardware floating point onboard the CPU itself. The ARM family does not. Hence the usual need for soft-float. Basically it means that your applications will be able to run floating point operations (FFT's and PID controllers are good examples of that), albeit more slowly than a hardware implementation would allow.

[ratul]

hi ,,,,,,i did my porting by keeping this soft float in /opt
while compiling the programs i used make comand with
make -msof-float

then also i am getting the floating loint error on board,,,,,
i did some googled ,,,,,,,,some r saying dat may be libgcc.a is not working properly,,,,pls sugest me something

[Rubberman]

You may need to reconfigure and rebuild your kernel. When you run "make menuconfig" on the kernel source, some of the configuration entries should be related to floating point support in the kernel. Embedded systems often are built without floating point support in order to reduce kernel and module size. The configuration options for ARM chips include an entry to floating point emulation options. You need to verify that you have at least one option selected. Normally this would be the "NWFPE math emulation" option.

[ratul]

sir,,,,i understood wat u told but i dont know how to modify NWFPE,,,,it will be very thankfull if u explain me ,,,,,,,i googled but still now my concept is not clear,,,,,how i will rebuild the kernel i dont know

[Rubberman]

You need to do some study then before you go any further. There are help pages on various sites as to the steps to take in configuring and building a kernel. Also, you need to review the documentation from the device vendor on how to exactly to re-image your device with a new kernel, etc. This is a very broad, and deep subject and it is, in my opinion, too big to get into such details until you have a better understanding of what you need to do. The deails of what/how you will reimage your device depends upon whether it boots from embedded flash memory, an external device such as SD or CF card, etc.

So, before I can help you much more here, you need to do the following:

1. Determine which Linux distribution+version (not just the kenel version) that you are using on the device.
2. Learn how to configure and build your kernel for the embedded system on a host system.
3. Verify that you are correctly installing the new kernel and operating system on the device. First, configure and build the kernel with the original parameters (if you have the kernel's original .config file), install, and test that that works on the device. Then, modify the configuration as needed and install and test that kernel as well.
4. Determine if you need to rebuild system libraries or not and do that as necessary.

Personally, as much as possible I try only to build a kernel on a non-arm host (such as my x86_64 workstation), and everything else on the device if at all possible. There are ARM emulators for x86 Linux that can be used to do this as well if you don't have enough room on the device for the entire GNU tool chain.