[yocto] RPi app built with SDK won't load

[Pierre FICHEUX]

Did you try compiling in text mode?

$  $CC -o test test.c

-- 
Pierre FICHEUX -/- CTO Smile-ECS, France -\- pierre.ficheux at smile.fr
                                     http://www.smile.fr
                                     http://ingenierie.openwide.fr
I would love to change the world, but they won't give me the source 
code

Le 2017-07-02 03:07, Paul D. DeRocco a écrit :
>> From: Andrea Galbusera [mailto:gizero at gmail.com]
>> 
>> Could you please post the exact source code of your test
>> program and the steps you take to (a) build the SDK and (b)
>> build your test executable? Is your running image a pretty
>> standard one (core-image-minimal, rpi-test-image or so) or do
>> your own with custom features?
> 
> It did have some custom features, so I did a plain build of
> core-image-minimal using raspberrypi3 as the MACHINE. I also did a
> populate_sdk for it, and installed the SDK in /opt/poky/2.2.1-a32 by
> running the install script.
> 
> The test program test.c is just "int main(void) { return 0; }". I
> normally use Eclipse CDT to compile native programs, so I set up a
> cross project using the SDK, which involves a few manual settings,
> including telling it the tools are in
> /opt/poky/2.2.1-a32/sysroots/x86_64-pokysdk-linux/usr/bin/arm-poky-linux,
> and adding a --sysroot to the command lines. The compiler command
> line came out as:
> 
> arm-poky-linux-gcc
> --sysroot=/opt/poky/2.2.1-a32/sysroots/cortexa7hf-neon-vfpv4-poky-linux-gnueabi
> -O3 -Wall -c -mfloat-abi=hard -MMD -MP -MF"test.d" -MT"test.o" -o
> "test.o" "../test.c"
> 
> (without the line breaks). I had to add "-mfloat-abi-hard" to get it
> to link. The link command line was:
> 
> arm-poky-linux-gcc
> --sysroot=/opt/poky/2.2.1-a32/sysroots/cortexa7hf-neon-vfpv4-poky-linux-gnueabi
> -s -o "test" ./test.o
> 
> (again, without the line breaks). After dd-ing the image to my SD
> card, I mounted it and manually copied the "test" program into its
> rootfs. When I stuck it in the RPi3 and ran it, I got
> 
>     -sh: ./test: not found
> 
> The shell in this case is busybox, so the error message is slightly
> different from bash.
> 
> I rechecked everything I had described before, analyzing the
> executable and comparing it to some working executable from the
> rootfs. There must be SOMETHING in my executable that the loader is
> barfing on, after it's successfully opened the file but before it
> starts looking for libraries. But it's an awfully small executable, so
> it's hard to imaging where that something is hiding.
> 
> --
> 
> Ciao,               Paul D. DeRocco
> Paul                mailto:pderocco at ix.netcom.com