PROCESSOR-SDK-AM335X: Yocto build of MLO and U-boot for SPI flash

Milton Lie

I'm building MLO/u-boot images in yocto environment. Have image (MLO/u-boot/kernel/apps) working for sdcard. Board is a beaglebone derivative with SPI NOR flash. Does anyone know if yocto builds can be configured to build MLO/u-boot for SPI? I see references such as http://processors.wiki.ti.com/index.php/AM335x_U-Boot_User's_Guide#SPI_2 that reference TI SDKs, but I would like to build in my existing Yocto environment.

over 8 years ago

0 Kemal R. Shakir over 8 years ago

TI__Guru 55345 points

Hello Milton,

Please, change the UBOOT_MACHINE = "am335x_evm_config" to UBOOT_MACHINE = "am335x_evm_spiboot_config" in <tisdk>/sources/meta-ti/conf/machine/include/ti33x.inc to build the U-boot with am335x_evm_spiboot_defconfig file.

Best regards,
Kemal

0 Milton Lie over 8 years ago in reply to Kemal R. Shakir

Prodigy 140 points

Thanks for the quick response. Will try it out later today.

0 Milton Lie over 8 years ago in reply to Milton Lie

Prodigy 140 points

How about building MLO/u-boot for peripheral boot over UART. Future batch of boards will not have sdcard connector, so need image I can boot over UART to program SPI NOR flash.

0 Kemal R. Shakir over 8 years ago in reply to Milton Lie

TI__Guru 55345 points

You use the default am335x_evm_config to boot over UART.

0 Milton Lie over 8 years ago in reply to Kemal R. Shakir

Prodigy 140 points

Built with am335x_evm_spiboot_defconfig (yocto pyro), but MLO.byteswap was not generated. Is there a way for me to generate it?

0 Kemal R. Shakir over 8 years ago in reply to Milton Lie

TI__Guru 55345 points

You can find the MLO.byteswap here <tisdk>/build/arago-tmp-external-linaro-toolchain/work/am335x_evm-linux-gnueabi/u-boot-ti-staging/<version>/build/MLO.byteswap.

0 Milton Lie over 8 years ago in reply to Kemal R. Shakir

Prodigy 140 points

Thanks Kemal.
Actually I just wrote a C utility to do the byteswap, and got MLO/u-boot booting from SPI NOR flash.

Now I'm stuck with booting from UART. I'm using the default MLO that works on my sdcard. But when I send it via UART using XMODEM Transfer Protocol with 1K Block Size, I see it transferring the MLO image, but after that it hangs.
Following instructions from processors.wiki.ti.com/.../AM335x_U-Boot_User's_Guide

0 Kemal R. Shakir over 8 years ago in reply to Milton Lie

TI__Guru 55345 points

You need to send u-boot-<version>/spl/u-boot-spl.bin instead of default MLO. Please, create a new thread if you face new obstacles regarding UART boot.

0 Milton Lie over 8 years ago in reply to Kemal R. Shakir

Prodigy 140 points

Thanks for the info Kemal. Did not use this image before, and did not realize they were available at

tmp/work/beaglebone-poky-linux-musleabi/u-boot/1_2017.01-r0/build/spl/u-boot-spl.bin in my yocto build.

All working now. Also realized MLO.byteswap was generated in the build directory, but not moved to the deploy area by the deploy recipe.

Everything works now. Thanks again for the pointers.

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PROCESSOR-SDK-AM335X: Yocto build of MLO and U-boot for SPI flash