Just a note to point out that, while the Pico SDK will usually generate UF2's no larger than twice the size of maximum Flash, there is nothing which prohibits other things being included in a UF2 file; source code, embedded files, debugging symbols, even images for other microcontrollers.
A 'Universal Pico UF2' will include separate images for both RP2040 and RP235X so could be 64MB or larger.
Presenting a disk size of 128MB will allow a 64MB UF2 to be loaded when a disk size of 64MB probably wouldn't, because some 8KB of it is used leaving less than 64MB free. I have however wondered why the limit is 128MB and not larger.
It seems to me, no matter what the disk size presented, the number of sectors of hard-coded data required within ROM to present it, would be the same, the rest being all zero bytes which don't need to appear within ROM. This is what makes me think the chosen disk size is more arbitrary than not.
A 'Universal Pico UF2' will include separate images for both RP2040 and RP235X so could be 64MB or larger.
Presenting a disk size of 128MB will allow a 64MB UF2 to be loaded when a disk size of 64MB probably wouldn't, because some 8KB of it is used leaving less than 64MB free. I have however wondered why the limit is 128MB and not larger.
It seems to me, no matter what the disk size presented, the number of sectors of hard-coded data required within ROM to present it, would be the same, the rest being all zero bytes which don't need to appear within ROM. This is what makes me think the chosen disk size is more arbitrary than not.
Statistics: Posted by hippy — Fri Aug 15, 2025 2:35 pm