Attempting to boot u-boot from USB on iMX8x. The boot.scr does not boot u-boot, it boots the kernel on iMX8X BSP 5.1.
What are the boot args or boot cmd to boot the U-boot directly from the USB?
If there are environment variables similar to the following to boot the USB u-boot, please explain what is needed. I can boot to the eMMC u-boot and then run usb boot command after making sure that u-boot does the usb start and recognizes the u-boot, but this boots directly to the kernel and bypasses the u-boot on the USB.
Where exactly did you get the idea from that any such would be possible? All of the i.MX 8 series based modules boot exclusively from on-module eMMC flash. This is factory fused and can NOT be changed.
It doesn’t matter if it is factory fused to the eMMC. You should be able to add bootargs/bootcmdds to the boot.scr and boot uboot and the kernel from uboot. This is not possible on SD because Toradex removed SD boot capability from i.MX8X based products. No boot jumpers or default boot from SD. Customers should be able to boot from whatever media they choose, SD, USB, eMMC, NOR or whatever media they wish.
It doesn’t matter if it is factory fused to the eMMC. You should be able to add bootargs/bootcmdds to the boot.scr and boot uboot and the kernel from uboot.
If you say so. However, I am afraid I do not know what exactly you are talking about here, sorry. I really don’t think boot.scr has anything to do with where exactly U-Boot would be loaded from. That is exclusively either fused or strapped. Well, OK. On some other SoCs there may be a way to kind of second boot from a different boot source but unfortunately NXP told us that on SCFW enabled ones (e.g. the i.MX 8/8X plus actually unfortunately the i.MX 8M Mini and i.MX 8M Plus as well for that matter) this is really not possible.
This is not possible on SD because Toradex removed SD boot capability from i.MX8X based products.
I am not sure what exactly you are referring to here. As mentioned above NXP did not left us any choice. If one fuses a boot source on them i.MX 8 series SoCs then there is no way to ever boot from anywhere else again (except the recovery aka serial download mode).
No boot jumpers or default boot from SD.
There really simply exists no such option, sorry.
Customers should be able to boot from whatever media they choose, SD, USB, eMMC, NOR or whatever media they wish.
That is really not how we see it resp. if that is really what you want that is absolutely possible. You may customise this as part of our Build-To-Order process (please contact sales). Then you may fuse or not fuse, strap or not strap whatever you like. However, for most of our regular customers they just prefer their modules to boot in the most convenient and robust way which is from on-module flash storage being eMMC in this case.