Heinrich Schuchardt <heinrich.schucha...@canonical.com> writes: > > High Jon, > > thanks for pointing out where the specification is unclear. > > I guess a half-sentence is missing saying "if both a dedicated firmware > partition and the EFI system partition are both supported by the > firmware".
If I follow you, more precisely it is if a *separate* dedicated firmware partition and ESP are supported as firmware locations. For example, with TI ROM, it always loads the firmware from the boot partition. So designating the dedicated firmware partition is done by making it the boot partition. It also supports firmware in the ESP, but only if you make the ESP the boot partition. Which then they are really the same partition. But I question the purpose of the sentence at the end of 4.2: In both cases, the recommended boot sequence is to first search for firmware in a dedicated firmware partition, and second search for firmware in the ESP. because it is stated at the beginning of 4: In general, EBBR compliant platforms should use dedicated storage for boot firmware images and data, independent of the storage used for OS partitions and the EFI System Partition (ESP). Was the point of the sentence in 4.2 really that the EBBR prefers the choice of firmware placement in a dedicated partition, but if you have to, it can be in the ESP, *and* that this choice should be the same for fixed and removable storage? > > The EBBR is still evolving. If you have a suggestion for improvement, > please, create an incident or merge request on Github. Created https://github.com/ARM-software/ebbr/issues/113 for clarification of 4.2.2. > Consider joining > one of our meetings. See > https://github.com/ARM-software/ebbr/wiki/EBBR-Meetings#datetime I had wanted to bring this up in person, but I am on vacation for the next 2 weeks. I hope I can make the following meeting. >> As a side question, I'm not sure of the practicality of recommending a >> boot sequence that looks in two places, at least for the very first >> firmware stages, as ROM usually is very simple and only looks in a >> single location. > > The documentation is not only about what a boot ROM does. E.g. I have > seen a boot ROM loading U-Boot SPL from flash and U-Boot SPL loading EDK > II from /EFI/vendor/board/firmware.itb. But U-Boot SPL in this case > would only scan the ESP. So that raises another issue. Your statement above implies, I think, that different stages of firmware can live in different places, which does happen. But I had read the spec as implying that firmware must be at a single location. Can you clarify? thanks Jon _______________________________________________ boot-architecture mailing list -- boot-architecture@lists.linaro.org To unsubscribe send an email to boot-architecture-le...@lists.linaro.org
