Hi JP, On 30.03.2017 17:48, Joshua Pincus wrote: > Hi Zoran, > > Thanks for your reply. > > My situation is this: When the VM guest comes up the first time from a > system-level reset (aka power on), the Broadwell HD graphics device runs > fine. I see basic VGA both before and during the boot of Windows. Once > Windows boots, the HD graphics device is configured by Intel's driver and I > see hi-rez output. On a reboot of Windows within the VM, an FLR is > issued. When the guest comes back up, no VGA. Windows does boot but > provides no VGA output. If Windows needs to drop into VGA mode so that a > user can access the real-mode functionality of the recovery console, still > no VGA.
what kind of VM? what does it usually do when booting to support windows (supposedly runs some BIOS / UEFI code)? Does that include running a VBIOS or GOP UEFI driver? > > It's only on Broadwell-based boards that we have this problem. If we issue > FLRs during the reset of the PCI bus for older Intel boards, no problem. > We get VGA. Something involved with the FLR is messing up the state of the > hardware instead of actually returning the hardware to a virgin state, akin > to what you would get from a full system reset. AFAIK, Windows doesn't need a virgin state but the state the VBIOS / GOP driver usually leaves the hardware in. Plus a Video BIOS Table (VBT) with some hints about a board's specifics. What are these older boards? Are you sure they support FLR? The first hints about FLR support I could find were is a Haswell datasheet. Nico -- coreboot mailing list: coreboot@coreboot.org https://www.coreboot.org/mailman/listinfo/coreboot