I compile buildroot with attached config for SAMA5D3 ARM CPU. When I enable EABIHF and VFPv3-D16  (I test all combination of VFP)  nodejs always crash with illegal instruction. I test many combination of version buildroot but always crash. But I found solution. When I compile nodejs ouside buidroot but using buildroot toolchain. All works perfect. When I backtrace and disassemble code I found
that nodejs crash here:

 0x0073ddec <+160>:   vldr    d17, [r2]

If I understand this well that when I compile for VFPv3-D16 there should not be 
register D17 used. This generate illegal instruction. 

When I use this configure:

export CC=arm-buildroot-linux-uclibcgnueabihf-gcc  
export CXX=arm-buildroot-linux-uclibcgnueabihf-g++ 
export  CC_host="gcc -m32" 
export CXX_host="g++ -m32" 


/configure --prefix=../install --dest-cpu=arm --cross-compiling --dest-os=linux   --with-arm-float-abi=hard --with-arm-fpu=vfpv3-d16

I mean then inside buidroot is to configure  passed wrong options with-arm-fpu=vfpv3-d16.

Don't  hestiate contact me.

Dan