Pi3 not booting with bluetooth disabled

Hi,

i have a custom built Image (Pi-gen) wich is running on Kernel 5.4.83. I need to use the ttyAMA0 and therefore i have the bluetooth disabled via the config.txt:

# ttyAMA0/RS232
dtoverlay=pi3-disable-bt
#dtoverlay=pi3-minuart-bt

# I2C
dtparam=i2c_arm=on

# Enable UART
enable_uart=1

now when i boot uboot seems to get stuck. The only output on serial i see is:

U-Boot 2020.01-g83cf4883ec (Mar 09 2021 - 08:11:03 +0000)

DRAM: 948 MiB
RPI 3 Model B (0xa22082)

When i comment the dtoverlay=pi3-disable-bt everything works fine.

I see that the Problem is known and in the Pi3 board integration Guide this Workaround is linked.

Now i cant get my head around how and where to apply this “patch”. Can someone help me to get my ttyAMA0 working ?

I guess you will need to generate a custom U-Boot binary with that patch applied. The current mender-convert utility uses a custom-built binary based on this fork of U-Boot. You probably need to start with that and see if you can apply the patch and build.

Drew

Hey thanks for the answer.

i forked the mender uboot and aplied the patch. then I forked the mender integration file creator and modified it to use my patched uboot. Finally I forked mender convert to use my patched binaries and it seems to work so far :slight_smile: