Hi Colin,
Is there a smarter way to understand how much RAM is actually needed here, rather than using blunt tools like "double until it works"?
to add a bit of background info to Alex' reply, the RAM demand of the boot_fb_drv increased due to the system-wide change of the pixel format from 16 to 32 bits per pixel.
[1] https://genode.org/documentation/release-notes/20.08#Streamlined_pixel_forma...
As for your question of determining the resource demands, init supports the reporting of the consumed resources per child. For the dynamic init instance hosted inside the drivers subsystem, this reporting is enabled by default. You can find the report at /report/drivers/dynamic/state. Note that the 'used' and 'avail' values do not add up to the 'assigned' value. This is because a component lends quota to the services it uses. I think, the 'avail' value is of most interest as it denotes the RAM quota wasted.
Cheers Norman