Template:GLSDK Supported bootmodes

Supported Boot modes
The same U-Boot image shipped with the SDK can be used to boot the system in following different modes based on the boot switch settings:

= Booting EVM with different modes =

Choosing the correct device tree
Booting Linux kernel needs to have a kernel image(zImage) and device tree blob(DTB) file. DTB file describes the hierarchy of the devices, and also describes various parameters about the devices.

Depending on which CPU board and application board you are trying to boot, there are different set of devices. For each permutation, there is a different DTB file describing all devices on baseboard as well as application board.

Release filesystem comes with most commonly used permutations of device trees. Following table shows the name of the device tree file to be used for each of the combination.

U-boot tries to detect the platform (J6/J6eco) and choose the appropriate dtb. For the DRA7xx boards, it only detects the baseboard. If you are using a stackup of baseboard plus LCD, then you must manually specify the proper dtb by defining fdtfile inside uenv.txt. For example, if you were using J6 EVM + 10inch LG LCD then you would add the following line to uenv.txt:

fdtfile=dra7-evm-lcd-lg.dtb

Choosing the correct bootloader config
All the padmux is performed from the first stage bootloader (MLO) instead of the kernel. Also, the bootloader takes care of configuring all the required PADs as well as the IOdelay configuration. Depending on the use case, boot loader needs to know the required pads to be configured at the boot time. Kernel would know the device information from DTB file but bootloader does not know which DTB file would be used by the kernel.

For this reason, we need to rebuild the bootloader (MLO) with a different config so that the appropriate PAD and IODELAY configuration is performed as required by the use case. Release prebuilt bootloader works for most of the use cases.

When using vision use cases, rebuild the bootloader with extra Kconfig CONFIG_TARGET_DRA7XX_EVM_VISION enabled

Description
This template lists supported boot modes on

Parameters
This template takes following parameters - platform, in DRA7xx, OMAP5

Example
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