Hi all. I need clarification on where firmware should be located when
booting from removable shared storage. Statements in the intro of 4.2
seem to contradict later statements in 4.2.2 of the EBBR [1].
Section 4.2.2 states that to make it easier to use stock OS images on
removable storage, firmware should be located on the ESP partition (so
you don't have to create a dedicated firmware partition).
> On removable media, firmware should be stored in the ESP under the
> /FIRMWARE directory structure as described in Firmware Partition
> Filesystem.
However, prior in the 4.2 section, it states:
> The sections below discuss the requirements when using both fixed and
> removable storage. However, it should be noted that the recommended
> behaviour of firmware should be identical regardless of storage type.
> 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.
Why would the boot sequence for shared storage look in two places if it
is always in the ESP? Or does the statement in 4.2.2 only apply in the
case of using a stock OS image?
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.
thanks
Jon
[1] https://arm-software.github.io/ebbr/
