(01-10-2016, 01:46 PM)devilsclaw Wrote: The reason why I was trying to looking at a schematic is because I got the dev board yesterday and I'm looking into starting to develop for it. Not having to pull the sdcard every time I make a simple change would be nice. I don't want to do development on the pine its self since the sdcard could get corrupt while doing kernel development or the system might become un-bootable.USB boot is handled somewhat differently in Allwinner's SDK and in the mainline U-boot. For the mainline U-Boot, you can find more details here. A bit tricky thing is that the SPL load address is not 0x0 but 0x10000 in A64 and A80. We now have all the necessary changes in sunxi-tools now, but there were no people willing to test FEL USB boot on A80 (apparently A80 is not very popular).
For getting the mainline U-Boot up and running, the most important part is the DRAM controller initialization. For some Allwinner SoC variants this code became open sourced at https://github.com/allwinner-zh/bootload...loader/bsp under a proper GPL license. For the other SoC variants (Allwinner H3) it was more complicated and people had to disassemble the boot0 bootloader binary. If the Pine64 folks can ask Allwinner to open source the bootloader code for A64, then things are going to be a lot easier and more straightforward. Also thus speeding up the development significantly.
(01-10-2016, 01:57 PM)tllim Wrote: The developer board and production board are comes from same schematic. The only different is power LED light where developer board is green and production board is red color. We can release the schematic to developer in two to three weeks time.Thanks for this information and for the schematic release promise. While it is not available yet, could you please tell us how is the power getting supplied to the lower USB connector (the USB OTG one)? Is the VBUS pin directly connected to +5V or is there some kind of switch available to turn it on and off?
