I think there is a QEMU support for Legato Application Framework.
Could you provide some steps to start an emulation of a particular device (eg. WP77XX)
the QEMU support is not really documented as of now, and does not particularly emulate any Sierra platforms.
Instead you could consider it as an ‘ideal’ platform for Legato to run on that doesn’t require any hardware.
If you’re interested in that let me know.
PS: There is some minimal info on this page: Legato on Generic Linux
But as for a target that would allow to run wp77xx images and app just like a wp77xx, that doesn’t exist yet.
Could you provide your use case?