Most of our PC boards says it can boot from usb Actually , from Power on ,x86 jump to 0xFFFF0 and first instruction is jump to reset
All usb boot function implement in bios , you can skip the hardware driver , but you can not skip the BIOS On current ARM cpu , bootrom will like BIOS ? or U-boot like more ? The point is , USB stack , in current ARM cpu , instead of in BOOT ROM , almost implement in BOOT loader ,just like U-BOOT You can add the usb host and fat file system support to support USB stick rootfs , just like live cd ? But ,just personal curious , If you have the free on board eMMC , why you need to use a USB stick for rootfs ? 2014/1/8 William Hermans <yyrk...@gmail.com> > If you actually read the article, you would realize there is no need to > modify anything rh_ . . . > > > On Tue, Jan 7, 2014 at 7:56 PM, William Hermans <yyrk...@gmail.com> wrote: > >> >> >> On Tue, Jan 7, 2014 at 7:55 PM, William Hermans <yyrk...@gmail.com>wrote: >> >>> Actually, its loading the kernel from the HDD. Only the uboot files need >>> be read, so as the device knows where to boot *from*. >>> >>> If you want to be a 100% nitpicking techno-junkie, then a purely 100% >>> SD/eMMC-less boot can be had by using eprom . . . as it stands, this form >>> of USB boot satisfies me, and 99% of the other people out there :) >>> >>> >>> On Tue, Jan 7, 2014 at 7:13 PM, rh_ <richard_hubb...@lavabit.com> wrote: >>> >>>> On Tue, 7 Jan 2014 16:18:00 -0600 >>>> Gerald Coley <ger...@beagleboard.org> wrote: >>>> >>>> > Correct. It is actually booting form the SD and then loading off the >>>> > HDD. The boards cannot boot direct off of USB. They need that >>>> > intermediate step. You could also use a large thumb drive like a >>>> > 128GB. >>>> >>>> You are correct those instructions should be modifed to note the >>>> reliance on >>>> the sd card or eMMC. >>>> >>>> I recall that the lack of booting straight from USB was designed in >>>> but I don't recall what the reason was. Do you know? It's common >>>> for devices to boot from USB and I even recall reading USB was checked >>>> during the boot process, after SPI (I think). I may have read that in >>>> the >>>> TRM or is it SRM...? >>>> >>>> -- >>>> 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/groups/opt_out. >>>> >>> >>> >> > -- > 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/groups/opt_out. > -- 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/groups/opt_out.
