hi According to Silicon Errata SPRZ360 section 3.1.3 Boot:
USB Boot ROM Code Uses Default DATAPOLARITY .The AM335x USB PHYs supports a DATAPOLARITY feature that allows the data plus (DP) and data minus (DM) data signals to be swapped. This feature was added to simplify PCB layout.In some cases, the DP and DM data signals may need to cross over each other to connect to the respective USB connector pins. Crossing these signals on the PCB may cause signal integrity issues if not implemented properly since they must be routed as high-speed differential transmission lines. The DATAPOLARITY feature in the USB PHYs can be used resolve this issue.The DATAPOLARITY feature is controlled by DATAPOLARITY_INV (bit 23) of the respective USB_CTRL register. The USB boot ROM code uses the default value for DATAPOLARITY_INV when booting from USB. Therefore, the PCB must be designed to use the default DATAPOLARITY if the system must support USB boot How Beagle bone black is designed . is this considered in the design ? On Wednesday, January 14, 2015 at 9:53:07 PM UTC+5:30, RobertCNelson wrote: > > On Wed, Jan 14, 2015 at 7:00 AM, <goku...@gmail.com <javascript:>> > wrote: > > How we can load the MLO and U-BOOT in beaglebone black though USB port? > I > > know it can be done by SD card/serial port and it will load to eMMC but > if > > I have a USB stick/External HDD/USB connected to host, how can MLO and > UBOOT > > be fetch through USB port and able transfer directly to eMMC. > > > > Once these are done and we get the UBOOT prompt, we can surely upload > the > > kernel image to any of the known memory interfaces . > > Well... It's not 100% of what you want.. but close.. > > First flash this "console" eMMC flasher: > > > http://elinux.org/Beagleboard:BeagleBoneBlack_Debian#BBB_.28All_Revs.29_eMMC_Flashers > > > After flashing has finished, remove microSD... > > From u-boot: > > ums 0 mmc 1 > > Now you can flash the "eMMC" thru usb the port.. (thanks to u-boot) > > Regards, > > -- > Robert Nelson > http://www.rcn-ee.com/ > -- 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
