shift6mq: update: postmarketOS installed on SD card (dual boot android)

This is an update of https://www.janwagemakers.be/jekyll/postmarketos/shift/2025/09/18/shift6mq_sdcard_postmarketos.html where I describe my dual boot setup between postmarketOS and android on my shift6mq shift-phone . Slot A: postmarketOS /boot with rootfs on SD card (mmcblk0) Slot B: android (shiftOS-G 5) This is mostly ment as a documentation for myself… I’ve found an easier way to update my…