Dear coreboot folks,
Am 10.11.20 um 16:23 schrieb werner.zeh@siemens.com:
We could introduce a Kconfig switch per driver and let the driver handle the bit. Everything else could be removed. This would make it easier to track the usages. It would be nice if we could agree on a naming scheme so that all switches are named similar which would make it easier to track the usage.
But there are cases where there is no driver in coreboot for a given PCI device which needs this bit. For now, we (Siemens) handle this cases on mainboard level. So either we need drivers for these devices (just simply setting the master bit) or we can agree on some kind of exceptions. I am open to everything.
Two more suggestions:
1. Log a warning for all those cases, that this might have security implications a.nd that it should be made sure, that the payload and OS do it themselves.
Warning: Bus master enabled for …. This impacts security, so ideally make sure your payload and OS is able to set it themselves.
2. Make it run-time configurable for easier testing.
Kind regards,
Paul