# Mender on pi4 with raspbian last version freeze on GPU boot sequence **URL:** \ **Category:** General Discussions\ **Created:** [January 24, 2024, 9:08am UTC](https://hub.mender.io/t/mender-on-pi4-with-raspbian-last-version-freeze-on-gpu-boot-sequence/6504 "2024-01-24T09:08:38Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Jerry](https://yyz2.discourse-cdn.com/flex036/user_avatar/hub.mender.io/jerry/32/931_2.png) [@Jerry](https://hub.mender.io/u/Jerry)\ **Post date:** [January 24, 2024, 9:08am UTC](https://hub.mender.io/t/mender-on-pi4-with-raspbian-last-version-freeze-on-gpu-boot-sequence/6504/1 "2024-01-24T09:08:38Z")
We created a custom raspbian image last days using the last raspbian apt package (apt upgrade OK). When we build the mender image from it, we face a boot problem on raspberry pi 4 (that did not occur with raspberry pi 3 and that did not occur with our golden image (before mender-convert)). The pi 4 get stuck just after the rainbow screen with a blinking cursor. After a long debugging sequence (using the serial UART console log), we figured out that if we replace the two following files with older versions, it makes the pi 4 boot : - start4.elf - fixup4.elf As we read online, these two files are related to GPU bootcode. Do someone know what can explain theses facts : - why does the mender building process affect the GPU boot sequence (as our golden image, without mender works well with both pi3 and pi4) - what have been changed in last GPU bootcode that can affect the boot on pi4 - is it safe to “just” replace these two files with working one or we may face weird problem because of GPU bootcode not in sync with system files Thanks for your help ---
**Author:** ![oleorhagen](https://yyz2.discourse-cdn.com/flex036/user_avatar/hub.mender.io/oleorhagen/32/297_2.png) [@oleorhagen](https://hub.mender.io/u/oleorhagen)\ **Post date:** [January 31, 2024, 12:16pm UTC](https://hub.mender.io/t/mender-on-pi4-with-raspbian-last-version-freeze-on-gpu-boot-sequence/6504/2 "2024-01-31T12:16:59Z")
Hi @Jerry We do replace the rpi boot-files with our own custom compiled u-boot binary for rpi. However, our current setup is only 32-bit compatible. We have been wanting to get the 64–bit support done for a while, but we are still not there unfortunately. ---
**Author:** ![Jerry](https://yyz2.discourse-cdn.com/flex036/user_avatar/hub.mender.io/jerry/32/931_2.png) [@Jerry](https://hub.mender.io/u/Jerry)\ **Post date:** [January 31, 2024, 2:55pm UTC](https://hub.mender.io/t/mender-on-pi4-with-raspbian-last-version-freeze-on-gpu-boot-sequence/6504/3 "2024-01-31T14:55:45Z")
Hi @oleorhagen : our raspberry pi4 distribution is the 32 bit one. So, it seems this is not related to this issue. Be the way : replacing the 2 files do fix the issue for us. We have tested this workaround for 2 weeks with no issue. But i would be pleased to understand what is the underlying issue. Regards ---
**Author:** ![Jerry](https://yyz2.discourse-cdn.com/flex036/user_avatar/hub.mender.io/jerry/32/931_2.png) [@Jerry](https://hub.mender.io/u/Jerry)\ **Post date:** [January 31, 2024, 2:57pm UTC](https://hub.mender.io/t/mender-on-pi4-with-raspbian-last-version-freeze-on-gpu-boot-sequence/6504/4 "2024-01-31T14:57:06Z")
@oleorhagen is the a place where i can find the list of replaced boot-files in order to do some searching ? ---
**Author:** ![oleorhagen](https://yyz2.discourse-cdn.com/flex036/user_avatar/hub.mender.io/oleorhagen/32/297_2.png) [@oleorhagen](https://hub.mender.io/u/oleorhagen)\ **Post date:** [February 1, 2024, 7:19am UTC](https://hub.mender.io/t/mender-on-pi4-with-raspbian-last-version-freeze-on-gpu-boot-sequence/6504/5 "2024-02-01T07:19:30Z")
> our raspberry pi4 distribution is the 32 bit one. So, it seems this is not related to this issue. Hmm, that is indeed unexpected then. Unless you guys are using a newer RaspiOS distribution than what we currently support ? (See the supported versions on the hub RPI page) > [@Jerry](#): > > Be the way : replacing the 2 files do fix the issue for us. We have tested this workaround for 2 weeks with no issue. > But i would be pleased to understand what is the underlying issue. Alright, good 🙂 I cannot be sure, I _thought_ we didn’t replace the `start.elf` files. > [@Jerry](#): > > @oleorhagen is the a place where i can find the list of replaced boot-files in order to do some searching ? Have a look here, in mender-convert. This is where we add u-boot as the bootloader, as the `kernel` so to speak, and have it again chain-load the real `kernel` >