Installing self-built image raspberry pi 4B

This is no doubt a noob question but I seem to be using the wrong vernacular when searching the vast pages of support.

I have successfully built my own openwrt for raspberry pi 4B and see a number of ipk packages under bin.

Would this be an incremental update to the existing stock snapshot?
Or can I write a new img to a clean microSD card?
Which img to use?

The latter.

Thank you.

Is one of these img files a combined image for all partitions on the microsd?

Am I missing a page somewhere on that breaks all of this down and how to use the build output to make a microSD build?

What images are you talking about? It's like you're showing us a picture of a dark room with the lights out. List the file names you have in bin/targets/. Usually there's an image you can easily dd onto your (removable) storage.

-rw-r--r--. 1 nnnn mmmm     1131 Mar  4 03:47 config.buildinfo
-rw-r--r--. 1 nnnn mmmm      337 Mar  4 03:47 feeds.buildinfo
-rw-r--r--. 1 nnnn mmmm 15140628 Mar  4 03:49 openwrt-bcm27xx-bcm2711-rpi-4-ext4-factory.img.gz
-rw-r--r--. 1 nnnn mmmm 15141423 Mar  4 03:49 openwrt-bcm27xx-bcm2711-rpi-4-ext4-sysupgrade.img.gz
-rw-r--r--. 1 nnnn mmmm     4002 Mar  4 03:49 openwrt-bcm27xx-bcm2711-rpi-4.manifest
-rw-r--r--. 1 nnnn mmmm 13673573 Mar  4 03:49 openwrt-bcm27xx-bcm2711-rpi-4-squashfs-factory.img.gz
-rw-r--r--. 1 nnnn mmmm 13674369 Mar  4 03:49 openwrt-bcm27xx-bcm2711-rpi-4-squashfs-sysupgrade.img.gz
drwxr-xr-x. 2 nnnn mmmm     8192 Mar  4 03:48 packages
-rw-r--r--. 1 nnnn mmmm      832 Mar  4 03:49 sha256sums
-rw-r--r--. 1 nnnn mmmm       15 Mar  4 03:47 version.buildinfo

As per OpenWrt naming convention, images with 'sysupgrade' in the name can be flashed using the sysupgrade utility on OpenWrt. Those images you can use to upgrade an existing installation.

The factory images are meant for installations 'from scratch' - or from OEM firmware, when talking about networking hardware; yours is a SBC and those work differently.

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and write
" openwrt-bcm27xx-bcm2711-rpi-4-ext4-factory.img "
to any sdcard with balenaEtcher(

I've been using squashfs to write img to microSD cards.
What's the difference between using ext4 and squashfs for the microSD setup?


  • you can reset to defaults with 'firstboot'
  • some minor gains with relation to disk usage
  • some additional backup and restore abilities ( files changed in /etc/ )
  • probably a little more 'path-well-tread' with relation to disk issues although with sdcards this point is largely mute (2c)...
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