Oh, thanks, William, I was inspired doing this by your post! The problem is that "usb start" starts *u-boot*'s USB subsystem, it (probably) has nothing to do with the CPU. You explicitly mentioned that used a USB HDD with external power supply, but I'm trying to boot off a USB flash drive. The CPU doesn't provide USB power at early stage. If I provide power from an external source, everything works fine.
The latest u-boot supports loading overlays, I'm not sure whether it's possible to load an overlays with the correct configuration of that pin and *then* load kernel and stuff from USB flash drive. On Friday, June 30, 2017 at 9:46:27 PM UTC-6, William Hermans wrote: > > > > On Fri, Jun 30, 2017 at 7:50 PM, Sergey Manucharian <[email protected] > <javascript:>> wrote: > >> From this thread https://e2e.ti.com/support/arm/sitara_arm/f/791/t/270060 >> : >> Modifying bit 0 of 8 bit register address 0x47401C60 it switch on/off >> USB1_DRVVBUS pin >> > > But I don't think you have to do all that. Read my post from nearly 4 > years ago here: > http://www.embeddedhobbyist.com/2013/07/beaglebone-black-usb-boot/ > > Scroll down where I talk about uEnv.txt. "usb start" should initiate > power, and the driver. Note that I'm calling it first before loading files > over USB. If you require in depth details, you'll have to read through the > source code. But I might be able to answer *some* questions. I'm by no > means a uboot expert. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/cbb243a0-bb18-4fec-b9b9-d407aae15166%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
