The following patch:

https://gitorious.org/qt-platform-mkspecs/qt-platform-mkspecs/blobs/master/5.0/linux-rasp-pi-g++/patches/0001-Disable-v8-ARM-hardfloat-assumption.patch

is required to get a usable v8 compiled for ARMv6 targets with softfp support. Without this patch, an illegal instruction is generated.

The relevant section is:

#if defined(_VFP_FP) && !defined(SOFTFP_)
answer |= 1u << VFP3 | 1u << ARMv7;
#endif // defined(_VFP_FP) && !defined(SOFTFP_)

which appears to assume if we have floating point support and are using softfp (soft calling conventions with hardware instructions being generated) then we are automatically using hardware with VFP3 support, which is sadly not the case.

We get major gains from enabling softfp on this hardware and commenting out this assumption resolves the crash.