The bootloader U-Boot

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Overview

This page is meant to be a starting point for people to learn build a u-boot image and show to people the current status of different u-boot versions for IGEP Processor Boards.

What is U-Boot?

Das U-Boot (Universal Bootloader) is an open source, primary boot loader used in embedded devices. Its primary purpose in the shipping system is to load some operating system.

That means that U-Boot is necessary to perform a certain task, but it's nothing you want to throw any significant resources at. Typically U-Boot is stored in relatively small NOR flash memory, which is expensive compared to the much larger NAND devices often used to store the operating system and the application.


Necessary package

   


Download U-Boot Source

 First of all, will be a distintion between NXP-processors products and ARM-processors products. Because there are different kinds of U-Boot depending the processor.


Commercial Name U-Boot Series
IGEPv2 DM3730 U-boot-ARM
IGEP COM MODULE DM3730/AM3703 U-boot-ARM 
IGEP COM AQUILA AM335x U-boot-ARM 
IGEPv5 OMAP5432 U-boot-ARM 
IGEP SMARC AM335x U-boot-ARM 
IGEP SMARC iMX6  U-boot-NXP-Freescale
  • Once we know which U-Boot have we will clone the corresponding git repository.


U-Boot ARM Series

If we have an ARM series we will follow this table to get our source of U-Boot


Downloading binary files/U-Boot Source
Clone the u-boot repository

Clone the u-boot repository using git address:

$ git@git.isee.biz:arm-boot/u-boot-arm.git 

or

 $ git clone https://git.isee.biz/arm-boot/u-boot-arm.git

Checkout u-boot repository

Go to the u-boot-arm directory and checkout the isee_v2017.03 as:

$ cd u-boot-arm

$ git checkout remotes/origin/isee_v2017.03 -b isee_v2017.03 

U-Boot Freescale-NXP  Serie

If we have an Freescale-NXP series we will follow this table to get our source of U-Boot
Downloading binary files/U-Boot Source
Clone the u-boot repository

Clone the u-boot repository using git address:

$ git clone git@git.isee.biz:arm-boot/u-boot-imx.git

or

 $ git clone https://git.isee.biz/arm-boot/u-boot-imx.git

Checkout u-boot repository

Go to the u-boot-imx directory and checkout the isee_imx_v2017.03.y as:

$ cd u-boot-imx

$ git checkout remotes/origin/isee_imx_v2017.03_4.9.11_1.0.0_ga -b isee_imx_v2017.03_4.9.11_1.0.0_ga 

Prepare your U-BOOT

Once we have downloaded the U-Boot source. We will execute the file called defconfig that it variates in function of each model.

In order to load the default configuration of the target board, we have to write the following command:

 $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-[defconfig]
  • In the following table we will show you our diferent models with their defconfig and an example with our compiler.


Module Defconfig Example
IGEPv2 DM3730 igep0020_defconfig $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- igep0020_defconfig
IGEP COM MODULE DM3730/AM3703 igep0030_defconfig $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- igep0030_defconfig
IGEP COM AQUILA AM335x

am335x_igep0033_defconfig

$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- am335x_igep0033_defconfig
IGEPv5 OMAP5432   $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- 
IGEP SMARC AM335x am335x_igep0034_defconfig $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- am335x_igep0034_defconfig
IGEP SMARC iMX6 igep0046_imx6dl_2G_defconfig $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- igep0046_imx6dl_2G_defconfig


Build your U-BOOT

After running the defconfig. You can build u-boot by executing this command:

  $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-
  • After doing that we will have our U-Boot ready with their files to execute.
    • The result for ARM processor based board will be a MLO and u-boot.img.
    • The result for Freescale-NXP processor based will be a u-boot.imx.


You can install these files, for example, in the boot partition of a SD-card.  

What next...

After build u-boot you can use it for boot the board, exist several options for boot, check the Hardware Reference Manual about the options available for your board.


u-boot Freescale-NXP iMX6 series

u-boot Texas Instruments AM335x, OMAP3, DM3730, OMAP5432 series