Best posts made by Paulman9

@sebastian-roth I appreciate your help, and that does answer my question. For the record, though, the problem remains. Building from source using the fog provided (GitHub dev-branch pulled) console.h, general.h, and settings.h gives the same failure in hyper-v. Building from source, and only including ipxescript (not replacing the 3 files above) results in a undionly.kpxe that does work past initializing devices in hyper-v. I’m going through each option now to try to narrow it down as it seems now something in the config is what is tripping up hyper-v.

Edit: Modified the default ipxe general.h file to include param_cmd, and changed nothing else. Completed downloading an image to my vm on hyper-v. Unsure what I broke in the process, as there are a lot of switches I’m missing, but I can confirm this works on my setup.

Same issue with brand new setup on Debian 8.3, svn 6287. Any ideas? Everything works except multicasting.

After going though the differences one by one, I have narrowed it down to three switches that will cause the hang in hyper-v.
#define DOWNLOAD_PROTO_HTTPS
#define IMAGE_TRUST_CMD
#define CERT_CMD
Comment out those lines from the general.h (I used the files from dev-branch on GitHub, if they differ from master, then that might cause additional issues, didn’t check) and the current build (47849) of ipxe works in hyper-v. Would probably fix older versions too, but I don’t see any reason to downgrade as everything is working so far. Unsure how these are even affecting hyper-v at such an early state, but all I know is mine works with no other changes than that. Hope this helps someone make sense of this issue, or at least get around this if they are affected. Again, thanks for everyone’s help with this.