Creating an SD card image with results from yocto build


#1

Hi,

I have done a yacto build with meta-qcom for dragonboard-410c. I would like to write this image to an SD for booting the new image.

Since yacto does not generate an sd_card image, my other options seems to be to use the rootfs.img and the boot…img files to write on a pre-partitioned sd card. using the following commands:
sudo dd if=boot-XXX.img of=/dev/sdb9
sudo dd if=core-image-*.rootfs.img of=/dev/sdb8
I am using an sd card I created whith the dragonboard410c_sdcarnd_install_debin-246 file.

I have the boot image unfortunately, Yacto only generates the rootfs.ext4 and the rootfs.tar. Can anyone tell me how to generate the rootfs.img file from either of the above files.

Thanks,

Guy


#2

hi,

You can use this wiki to create a bootable SD card

In fact you should not write the .img file but the .ext4 image on the SD card. In general the .img refers to the ‘sparse image’ format which is used by fastboot when transfering files from PC to the board. The .ext4 is the full image (e.g. non sparsed), and that’s the one you need to write with dd into the rootfs partition.


#3

Thanks, for the quick reply.

I saw that wiki and that why I thought I needed the rootfs.img file.

I did try doing the dd with the ext4 file. Although it seems to writhe the folder is empty. I will try following the wiki from the beginning and see if this helps.

Thanks,

Guy


#4

Dear Ndec,

I have followed the instructions listed on 96boards/documentation/blob/master/ConsumerEdition/DragonBoard-410c/Guides/GPT.md, but I unfortunately, did not make it work, I have changed the boot–4.9-r0-dragonboard-410c-20170803052121.img to boot.img unzip and change core-image-base-dragonboard-410c-20170803052121.rootfs.ext4.gz to rootfs.ex4 and rootfs.img.

I am wondering if I need to format a SD card in certain format before I can execute the commands as listed in that web page.

Please advice,

Thank you in advance with best regards

Vincent


#5

Hi Ottgdouc,

Have you actually successfully created the bootable SD card for the dragonboard 410c? I am a bit desperate.

Regards

Vincent


#6

I was able to create the bootable SD following the instructions.

I did no format the SD. I did use the same SD card that I had previously loaded with the default Linux SD load.

Guy