Your ROOT_URL in app.ini is https://src.whiteboxsystems.nl/ but you are visiting http://src.whiteboxsystems.nl/Whitebox/u-boot/src/commit/535c74f80cb9eff0fa66ce750fc7fc8a8539635c/drivers/dfu You should set ROOT_URL correctly, otherwise the web may not work correctly.
upstream u-boot with additional patches for our devices/boards: https://lists.denx.de/pipermail/u-boot/2017-March/282789.html (AXP crashes) ; Gbit ethernet patch for some LIME2 revisions ; with SPI flash support
 
 
 
 
 
 
u-boot/drivers/dfu
Lukasz Majewski cb383cd21d dfu: MMC specific routines for DFU operation 13 years ago
..
Makefile
dfu.c
dfu_mmc.c