I am facing an issue where kernel built with gcc 5.2.0 hangs the board after the device tree is loaded.
I used current poky and meta-fsl-ppc layers to compile the image.
WARNING: adjusting available memory to 30000000
## Booting kernel from Legacy Image at 01000000 ...
Image Name: Linux-3.12.37-rt51
Image Type: PowerPC Linux Kernel Image (gzip compressed)
Data Size: 4789208 Bytes = 4.6 MiB
Load Address: 00000000
Entry Point: 00000000
Verifying Checksum ... OK
## Flattened Device Tree blob at 00e00000
Booting using the fdt blob at 0xe00000
Uncompressing Kernel Image ... OK
Loading Device Tree to 03fde000, end 03fffc40 ... OK
Note that this is observed only with the new v5.2.0 gcc and kernel built with gcc v4.9.1 boots just fine.