All COM are delivered with pre-installed U‑Boot bootloader firmware. U‑Boot supports several low-level-debugging options and file download via Ethernet (TFTP), USB or via UART/serial X/Y/Z-Modem. These files can additionally be stored into the permanent flash-memory (NAND/eMMC) to be started by command or power-on.
Further more can the user communicate with the bootloader via serial console, provided via RS232 using a `terminal-program`_.
To communicate with the CoM’s bootloader users need to connect to it via RS232 serial port, which dependent on the baseboard either is a D-SUB9 or pin-header (see Baseboard Pinouts, or TTL Debug UART pin header) connector, where the latter requires a TTL-2-USB RS232 converter.
- Connect the Debug UART (D-Sub 9, TTL pin header).
- Start Terminal program (Terminal Settings).
- Connecting the 5V DC power your board will boot.
- “Press any key” to abort the auto boot in U-Boot. (Can be pressed before message shows)
CTRL-C as this will not only abort the auto boot but also skip U-Boot hardware initilization, incl. skipping reading
some variables and settings from the enviornment, thus leaving the COM in a recovery state (NOT ROM recovery!).
For terminal program following are recommended:
Under Linux all above are usually available via the distribution’s package manger.
Power-On and Reset Output¶
After power up or reset, output of U‑Boot will appear on the console similar to this:
U-Boot 2015.10-rc2-04843-ge1be59f (Oct 23 2015 - 12:57:17 +0200) CPU: Freescale i.MX6SOLO rev1.2 at 792 MHz Temperature: Industrial grade (-40C to 105C) at 54C - calibration data 0x59a50669 Reset cause: POR I2C: ready DRAM: 256 MiB Board: Ka-Ro TX6S-8034 VDDCORE set to 1350mV VDDSOC set to 1350mV NAND: 128 MiB MMC: FSL_SDHC: 0, FSL_SDHC: 1 IPU HW Rev: 4 Baseboard: stk5-v3 MAC addr from fuse: 00:0c:c6:7c:6a:6d Net: FEC Hit any key to stop autoboot: 0 TX6S U-Boot >