[Buildroot] Illegal instruction when running some of the cross compiled binaries

[Buildroot] Illegal instruction when running some of the cross compiled binaries

[Divick Kishore]

Hi,
    I have built a custom root filesystem using build root, but
certain binaries (built with the packages selected during menuconfig)
when run give "Illegal Instruction".

# sshd
Illegal instruction

Having looked at the logs, the compiler flags used to build the binary
seems fine (-mtune=arm920t -march=armv4t -mabi=aapcs-linux
-msoft-float ) i.e. right for my H/W (ATMEL AT91RM9200).

1. Toolchain used CodeSourcery G++ Lite 2010.09-50
(arm-none-linux-gnueabi-gcc-4.5.1).
2. Linux kernel using the above mentioned toolchain.
3. Version of buildroot used is buildroot-2010.11.

Could anyone please suggest what is going wrong? It seems people have
similar kind of issue
(http://www.embeddedrelated.com/groups/AT91SAM/show/3547.php)
but the bug pointed for the issue doesn't seem to exist.

Another related issue that I see is that the pthreads libraries are
not copied in the rootfilesystem image from toolchain for some
reasons. Is it a known issue?

Thanks & Regards,
DivKis

[Buildroot] Illegal instruction when running some of the cross compiled binaries

[Thomas Petazzoni]

Hello Divick,

On Tue, 11 Jan 2011 17:55:15 +0530
Divick Kishore <divick.kishore@gmail.com> wrote:

>     I have built a custom root filesystem using build root, but
> certain binaries (built with the packages selected during menuconfig)
> when run give "Illegal Instruction".
> 
> # sshd
> Illegal instruction
> 
> Having looked at the logs, the compiler flags used to build the binary
> seems fine (-mtune=arm920t -march=armv4t -mabi=aapcs-linux
> -msoft-float ) i.e. right for my H/W (ATMEL AT91RM9200).

During compilation yes, but at the link stage of sshd, the
-march=armv4t flag is missing. Therefore, some ARMv5-only code gets
added to the binary. Maybe we need to add -march=armv4t to the
TARGET_LDFLAGS, or some other trick. I haven't tested anything for the
moment, so feel free to experiment.

Regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com