I had some success with my Banana PI and locally built sunxi tools. (here)

If anyone had any experiments or noteworthy success with the sunxi-fel and the OTG USB ports please chime in here too

I plan to document the process of preparing an Slackware Linux host on x86 (or whatever architecture) to access an ARM SBC by the means of it's native OTG USB port for the purpose of installing another Slackware system to it. Namely I plan to document the process for Orange PI PC v1.3.

why:
1. to avoid having a need for an dedicated MMC/SD card reader
2. possibly install directly to the eMMC
3. possibly avoid the need for an dedicated UART or other serial converter

goal:
A. running Slackware ARM host with networking or at least an serial port - preferably said OTG USB to continue the installation via network or serial line
B. generic - so applicable to any sunxi based host, supported by Slackware, with OTG port