That's an excellent news. Is it possible to push your changes upstream, so we could have a pic32 support right in the official u-boot release?
Systemd with all it's components takes almost 10Mb of resident memory. May be replacing it with runit would help, like in Void Linux.
Most of tools fit fine into 32Mb, except apt. May be we just need some replacement with a low footprint. Does Microchip have plans to extend the mz-da family by adding more memory on the chip? They already have a few Cortex-A5 based chips with 64 and 128 Mbytes of internal DDR2.