![]() ![]() However, the first four are usually given by a pre-processor macro (see arch/arm/boot/dts/im圆dl-pinfunc.h or im圆q-pinfunc.h respectively). Cells need to be assigned to the property, each pin requires 5 cells. To configure a pin, a device tree node inside the pin controller node with the property fsl,pins is required. The SoC level device trees define the base configuration and allow to extend entries through the iomuxc label. Pin configuration such as pinmux or drive strength is either set by pinctrl-im圆dl or the pinctrl-im圆q driver. Click on the box to see the current version of the respective device tree file. The modules Colibri iMX6S/iMX6DL share the same device tree binary, so do the modules Apalis iMX6D/iMX6Q. Set kernel parameters of where the kernel finds the rootfs imx8qxp-colibri-eval-v3.dtb)Īpalis: “eval" Colibri: “eval-v3" Verdin: “dev"Ĭarrier Board dependant (e.g. String with any device tree binary in boot partition The following table lists the most important environment variables and their default values: Environment Variable U-Boot Variables Environment Variables Įnvironment variables are key-value pairs of strings that are used by U-Boot as configuration or to execute commands. The following is an extract of what the console shows when U-Boot is initialized and autoboot is prevented by entering into the console. By default, U-Boot waits up to 3 seconds before starting the autoboot sequence. Once you can read the output from your host machine, the U-Boot Console can be easily accessed by pressing any button before the autoboot sequence starts. For detailed information on how to set up and configure the serial port on your host machine see our Quickstart Guide. In order to visualize the serial output from a host machine, a serial port reader program such as minicom or PuTTy is commonly set to read the corresponding USB serial port (e.g. While U-Boot's console output is also visible on the parallel RGB display (and with the carrier boards RAMDAC on VGA) a USB keyboard directly connected to the module does not work as of yet. The Iris Board routes this UART through a TTL to RS232 converter to a header (see Serial Adapter Cable on Iris). The Colibri and Apalis evaluation boards route this UART through a USB to Serial converter to a USB B connector or through a TTL to RS232 converter to a DB9 connector (see Colibri Evaluation Board, Apalis Evaluation Board). When U-Boot is running in RAM, it sends its output through the primary Full Function (FF) UART (usually UART_A). Built your own image from the Toradex Open Embedded meta layers in our git repositories.Used our Toradex Easy Installer to install a compatible image from our feed servers.Installed a compatible image from the Linux Software page on our site.A running U-Boot is automatically available if you have: In order to access the U-Boot console, you obviously need a running U-Boot in your module. To learn how to build your own U-Boot version, please refer to Build U-Boot and Linux Kernel from Source Code. This article explains how to manage the console and the environment variables in a running U-Boot so that you are able to troubleshoot, modify, or set up your own booting configuration. You can find the code in our repositories. Toradex also uses U-Boot as the bootloader for its images. The most remarkable achievement, however, is its good driver assortment, which has established it as the preferred bootloader for most embedded platforms. It features a console interface through the serial port with low-level commands and environment variables that provide high flexibility when configuring the boot process. Today, U-Boot is a fully-fledged bootloader supporting more than a dozen architectures, several filesystems, and a handful of interfaces. Shortly thereafter it was renamed U-Boot (short for Das Universal Boot) to reflect its evolution into a multi architectural bootloader. It has its origins in a very simple bootloader designed for the PowerPC architecture which was publicly released in 2000 under the name of PPCBoot. U-Boot is an open-source bootloader commonly used in embedded devices. If you are using version 5 LTS, please visit the 5 LTS version documentation. If you encounter issues, please Send Feedback. Some information may still apply to Toradex Linux BSP 6 configurations. This page has not been fully updated to reflect the changes made in Toradex Linux BSP 6. ![]()
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