TS-7970 uboot
This platform uses U-Boot as the bootloader to launch the full operating system. The i.MX6 processor loads U-Boot from the on-board 8 MiB SPI flash. U-Boot provides support for loading data from various mediums; this allows booting a kernel from SD, eMMC, SATA, NFS, or USB. U-Boot is a general purpose bootloader that is capable of booting into common Linux distributions, Android, Windows, or custom software OSes.
On a normal boot the output should be similar to the output below:
U-Boot 2014.10-gee73348 (Oct 07 2015 - 11:12:20) I2C: ready DRAM: 1 GiB MMC: FSL_SDHC: 0, FSL_SDHC: 1 SF: Detected N25Q64 with page size 256 Bytes, erase size 4 KiB, total 8 MiB In: serial Out: serial Err: serial Net: using phy at 7 FEC [PRIME]
By default the device will boot to SD or eMMC depending on the status of the "SD Boot" jumper on startup.
To break into the U-Boot console, press and hold the SW1 button while the unit is being powered up. This mode will also check for a USB mass storage device to use for production purposes.