[yocto] Screenshot tool

[Evan O'Loughlin]

Hi,

I’m currently using yocto to build a custom OS based on Linux 4.9 for our hardware:
Build Configuration:
BB_VERSION        = "1.32.0"
BUILD_SYS         = "x86_64-linux"
NATIVELSBSTRING   = "Ubuntu-16.04"
TARGET_SYS        = "arm-linux-gnueabi"
MACHINE           = "CUSTOM_MACHINE_NAME"
DISTRO            = "arago"
DISTRO_VERSION    = "2017.12"
TUNE_FEATURES     = "arm armv7a vfp thumb neon       callconvention-hard"
TARGET_FPU        = "hard"
meta-processor-sdk = "HEAD:92db4d8023d88ab59fab2953e7447ec0bd5a6db1"
meta-ros          = "HEAD:e2566402ab108a19634354a934788109422cf409"
meta-arago-distro 
meta-arago-extras = "HEAD:5b2a44b0c4d989133bc13d59398fd10375d351bb"
meta-browser      = "HEAD:26d50665e2f7223c5f4ad7481a8d2431e7cb55fb"
meta-openamp      = "HEAD:8a214032bfb7e8124bc1485c70c69f7d60abb819"
meta-qt5          = "HEAD:2c9f0e4eb0e9097f6f872ec1e1d81768a8ab5f1b"
meta-networking   
meta-ruby         
meta-python       
meta-oe           
meta-gnome        
meta-multimedia   = "HEAD:b40116cf457b88a2db14b86fda9627fb34d56ae6"
meta-ti           = "HEAD:3dc08477529b31ce887bb22a08201a843ded48f0"
meta-linaro-toolchain 
meta-optee        = "HEAD:d73e794c7e7ebb1cc5bf495a52a72b26fb118250"
meta              = "HEAD:39fd8c129e2bff7f2f1649b7f6e036ccc50fd5d8"
meta-custom  = "########################################"
meta-printing     = "morty:72811bc3755d1a943fa2a2e79601781b44a77420"


We run a Qt5 application using EGLFS but can no longer capture screenshots. 
In a previous yocto build based on Linux 3.x we were able to use a screenshot tool which effectively just read /dev/fb0 to a file.

I believe this was a change to how the underlying drivers interact with the GPU/Screen - I've started reading up on KMS/DRM.


Does anyone know is there a utility/tool which I could use to capture the Qt5 application as its drawn on screen?


Regards,
Evan