Cross-compiling Root for ARM Linux

ROOT
1

Hi,

I’m trying to cross-compile (from a SLC6 machine) Root to run on a Linux ARM (Linux socfpga 3.13.0-00298-g3c7cbb9-dirty #3 SMP Fri Jul 4 15:42:32 CST 2014 armv7l GNU/Linux).

I’m not so sure I understand whether that’s supported or not :blush:

I’ve tried :

./configure linuxarm --with-cc=/usr/local/DS-5/sw/gcc/bin/arm-linux-gnueabihf-gcc --with-cxx=/usr/local/DS-5/sw/gcc/bin/arm-linux-gnueabihf-g++ --with-f77=/usr/local/DS-5/sw/gcc/bin/arm-linux-gnueabihf-gfortran --with-ld=/usr/local/DS-5/sw/gcc/bin/arm-linux-gnueabihf-ld --minimal

but I immediately get lost of undefined symbols :

root]# make
/usr/local/DS-5/sw/gcc/bin/arm-linux-gnueabihf-ld -o bin/rmkdepend build/rmkdepend/cppsetup.o build/rmkdepend/ifparser.o build/rmkdepend/include.o build/rmkdepend/main.o build/rmkdepend/parse.o build/rmkdepend/pr.o build/rmkdepend/mainroot.o
/usr/local/DS-5/sw/gcc/bin/arm-linux-gnueabihf-ld: warning: cannot find entry symbol _start; defaulting to 000080b4
build/rmkdepend/cppsetup.o: In function my_if_errors': cppsetup.c:(.text+0x28): undefined reference tostrlen’
cppsetup.c:(.text+0x32): undefined reference to malloc' cppsetup.c:(.text+0x46): undefined reference tosprintf’
cppsetup.c:(.text+0x4c): undefined reference to strlen' cppsetup.c:(.text+0x68): undefined reference tofprintf’
cppsetup.c:(.text+0x98): undefined reference to _IO_putc' cppsetup.c:(.text+0xb2): undefined reference to_IO_putc’
cppsetup.c:(.text+0xd2): undefined reference to fprintf' cppsetup.c:(.text+0xd8): undefined reference tofree’
cppsetup.c:(.text+0xf0): undefined reference to `stderr’

Thanks for your help,

2

Hi,

It’s not that simple :slight_smile: As part of the build we build a few binaries that we need to build the rest of ROOT - they thus need to be built twice: once for the target and also once for the build platform.

We had this working for iOS; maybe you want to have a look whether you can extend what has been done there?

Alternatively a patch for CMake would be welcome, to enable cross-compilation for that.

Either way, this is on our list, we are aware that this is something we need to solve, especially for ARM.

Cheers, Axel.

3

Hi Axel,

Thanks for the answer. I’ll see what I can do, but no promise…

4

BTW, as I have a Mac I can try the IOS build to get an example of cross-compilation, right ?

Are there some instructions on how to cross-compile for IOS somewhere ?

Thanks

5

Hi,

I’m not aware of that :frowning: Is this good enough for the first steps? [Root for iPad

Cheers, Axel.