Maybe check to see if your board has a bad or missing EEPROM. Changing U-Boot and Linux for a hard-coded MAC address is more than just tedious. Serial transfer should be possible if u-boot has been compiled with command "loady" (Ymodem). Locked.
So, you say you have no ethernet. Well, that isn't a problem if you use your usb on-the-go port. I often upgrade u-boot using tftp so that I don't have to copy the new u-boot file to an sd card. Since version v2015.07, you can find the appropriate extension by. => print uboot_defconfig.
As I said earlier, U-Boot is a richly documented bootloader. The README file included with the package, for example, covers the use of U-Boot extensively. Among other things, it discusses the package's source code layout, the available build options, U-Boot's command set, and the typical...
Dec 10, 2020 · This can be done both in Linux (see below) or U-Boot (see below). U-Boot Support. U-Boot provides access to eMMC devices through the mmc command and interface but adds an additional argument to the mmc interface to describe the hardware partition. The interface is therefore described as 'mmc <dev> <part>' where 'dev' is the mmc device (some ...