| Running U-Boot |
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U-Boot is probably the most popular firmware monitor for Linux. It is developed and maintained by DENX Software Engineering (www.denx.de). If you need detailed information on any aspects of U-Boot operation, DENX publishes extensive U-Boot user documentation at their web site. On the SOLOX SOM, U-Boot image is stored in the NAND Flash device. On a power-on / reset, U-Boot is reloaded to the SDRAM and runs from there. As soon as the module is powered on or reset, the i.MX6 proceeds to boot the U-Boot firmware printing the following output to the serial console: U-Boot 2015.04-imx6sx-2.3.0 (Jan 25 2017 - 17:25:40) Note: Bad blocks are a normal thing for NAND Flash. The messages regarding bad blocks in the output above are a benign indication that U-Boot has correctly handled bad blocks found in the NAND Flash. If you hit any key on the serial console before the number of seconds defined by the U-Boot bootdelay variable has elapsed, you will enter the U-Boot interactive command monitor. From the command monitor you can run U-Boot commands to examine memory, load an image from Ethernet, boot Linux from a loaded image or perform any other action supported by U-Boot. If you hit any key on the serial console before the number of seconds defined by the U-Boot bootdelay variable has elapsed, you will enter the U-Boot interactive command monitor. From the command monitor you can run U-Boot commands to examine memory, load an image from Ethernet, boot Linux from a loaded image or perform any other action supported by U-Boot. Use the help command to print out the list of the enabled U-Boot commands: SLX-SOM U-Boot > help As mentioned above, the DENX website publishes detailed documentation describing use of various U-Boot commands. |