What happens for the Yocto Linux rootfs size?

[13614278]

We are using IMX8mini EVK, which is 8G emmc, running Yocto Linux

By default, the bitbake fsl-image-validation-imx would created a 1.3GB size of rootfs, like fsl-image-validation-imx-imx8mmevk.sdcard.bz2

After flashing the whole image, the linux would show the rootfs(/) is the same size as 1.3GB. But we all know our emmc is 8GB.

And I struggling this, found if add IMAGE_ROOTFS_SIZE with large number to increase the whole size. 

Obviouslly, this is un-reasonable, as we have to create 8GB file size of rootfs image, that's too large for both flash and copying. I am really feel confused that why Yocto Linux use such method? As most of the data byte must be ZERO-padding for this case, this is unnecessary at all.

For Android, the whole system.img is just 800MB, but the whole 8GB emmc can be usable and visable.

How could I let Yocto Linux have real data size(e.g, just 400MB), but the whole emmc storage also be visable and usable?

[gusarambula]

Hello Yang Songxiang,

I agree that it’s hard to fir the resulting image to your storage size. The following document may be helpful:

https://community.nxp.com/docs/DOC-105521

I would recommend increasing the free space (IMAGE_ROOTFS_EXTRA_SPACE), which is an easier parameter to setup in order to maximize the use of the storage used.

Regards,

[13614278]

Thank you very much, this is the first time that I got my expected answer on this website.