On Tue, Jul 06, 2021 at 05:05:19PM -0600, Simon Glass wrote:
Hi,
At present U-Boot avoids the concept of 'opening' a file. Being in a bootloader environment, it is normally better to take the action immediately and avoid any caching, for example, since there is no background task to clean up afterwards.
Having said that, the concept of a file is quite useful, for example to write the output of a command to a file, or to open a file and read it a line at a time.
Another case has come to light in that EFI wants to access files using a file handle. This currently uses parallel data structures and does not map very well in U-Boot.
Finally, partitions has a similar issue, where defining them as a device can have benefits, e.g. to specify the device to use directly, rather than with the 'type dev:part' approach, perhaps providing them in the devicetree, etc.
For the above reasons, I propose that we implement, as an option, support for files and partitions within driver model.
+1
# Nobody has commented yet :)
Regarding a "file (or file descriptor)", we have already implemented the same concept in efi_loader. So technically, it won't be a hard-work. Regarding "partitions as udevice," I have posted an experimental patch [1]. So it must also be feasible.
One of my concerns is what benefit end users may enjoy.
-Takahiro Akashi
[1] https://lists.denx.de/pipermail/u-boot/2019-February/357937.html https://lists.denx.de/pipermail/u-boot/2019-February/357934.html
Regards, Simon