U-Boot for CN913x

Revisions and Notes

Introduction

This page describes how to build, install and update U-Boot for SolidRun Armada 8040-based devices.

Prebuilt Binaries

Usable firmware binaries are available inside the u-boot sub-folder of any cn913x_build artifact.

There a variety of variants depending on SoC, and where U-Boot will be deployed:

• The SoC is indicated in the filename, e.g. u-boot-cn9132-cex7-A-mmc:1:0.bin is for the CN9130.

• The Carrier or Board follows the SoC name, e.g. u-boot-cn9130-cf-base-mmc:1:2.bin is for a Clearfog Base.

• The Boot Media follows the carrier or board name, e.g. u-boot-cn9130-cf-pro-spi.bin targets SPI flash. MMC variants specify 2 numbers:

  • number of mmc device (on Clearfog: 0 = eMMC, 1 = microSD)

  • number of spi partition (0 for data partition or microSD, 1 for boot0, 2 for boot1) e.g. u-boot-cn9130-cf-base-mmc:0:2.bin is for eMMC boot1.

Select Boot-Device

Please refer to the Boot-Select pages at our Developer Center for the configuration of the Boot-Select DIP Switches.

Deploy

From Linux

to microSD

First insert the target microSD into any computer running Linux and identify its canonical name in /dev, e.g. by reading through dmesg. Errors in this step will result in data loss!

The Boot ROM expects to find a bootable image at 512 bytes into the block device. Use dd for writing the previously compiled flash-image.bin to the designated location. In this example sdX is used as placeholder for the actual device name of your microSD on your system:

This process will also work on the device itself if it has already booted into Linux.

to eMMC data partition

Since the eMMC is soldered to the board, this procedure has to be done on the device itself after booting into a Linux system first. The process is identical to microSD.

to eMMC bootY

Since the eMMC is soldered to the board, this procedure has to be done on the device itself after booting into a Linux system first. Please note that as with the eMMC data partition, the Boot ROM expects to find the bootable image at the start of the partition without any offset.

To avoid accidents, the boot partitions are write protected by default. This protection is easy enough to turn off:

Now the bootable image can be written to either boot partition with dd:

As a last step, the eMMC has to be configured for selecting the intended boot partition. This can be done on the U-Boot console with the mmc partconf command, or from Linux with the mmc application from mmc-utils:

From U-Boot

to SPI Flash

This step requires U-Boot running on the target device first, e.g. loaded from microSD or UART. The flash-image.bin can then be loaded from either microSD, eMMC, USB or network, and finally written to the SPI flash. This sample covers the easiest case where flash-image.bin is available on a fat formatted partition on a USB drive:

Booting the board using UART

The CN913x can be booted through UART asa fall-back, when the configured boot media has no valid boot image. E.g. when the DIP switches are set to boot from SPI, but SPI flash is empty - the bootrom falls back to serial download.

This is mostly used for system manufacturing, unbricking etc ...

The tool provided by Marvell is available in our cn913x_build repository on GitHub along with Marvell's documentation.

Build From Source

• GitHub - SolidRun/cn913x_build