Before I have presentation named “i.MX6 SDCARD Secondary Boot Demo” in following link.
i.MX Development Miscellanea(i.MX 开发杂记) - NXP Community
Now I have the “i.MX8MM SDCARD Secondary Boot Demo”.
The big difference is i.MX8MM using spl.
And in the “i.MX6 SDCARD Secondary Boot Demo” I manually edit the secondary image table and manually combine the images.
Now, I have written done a script “imx_sd_secondary_boot_creator.sh” to do above.