I have been trying to install Ubuntu Mate 20.04 on a Raspberry Pi 3B+.
I was just following this tutorial, but I was facing some problems.
I downloaded the Ubuntu Mate 20.04.2 image from the official website. I selected the 32-bit version 20.04.2 LTS (Focal Fossa). I extracted the image and flashed it to a micro-SD 64GB class 10 using balenaEtcher.
When this was done, I inserted the micro-SD card in the Raspberry Pi 3B+, connected a monitor, a mouse and a keyboard and then powered it with a micro USB charger.
The following errors appeared in the screen:
[Firmware Bug]: Bootloader left irq enabled: bank 1 irq 9
cma: CMA area linux,cma could not be activated
DMA: failed to allocate 1024 KiB pool for atomic coherent allocation
kvm [1]: Error, CPU 0 not supported!
raspberrypi-exp-gpio soc:firmware:expgpio: Failed to get GPIO 0 config (-12 80)
raspberrypi-exp-gpio soc:firmware:expgpio: Failed to get GPIO 1 config (-12 81)
raspberrypi-exp-gpio soc:firmware:expgpio: Failed to get GPIO 2 config (-12 82)
raspberrypi-exp-gpio soc:firmware:expgpio: Failed to get GPIO 3 config (-12 83)
raspberrypi-exp-gpio soc:firmware:expgpio: Failed to get GPIO 4 config (-12 84)
raspberrypi-exp-gpio soc:firmware:expgpio: Failed to get GPIO 5 config (-12 85)
raspberrypi-exp-gpio soc:firmware:expgpio: Failed to get GPIO 6 config (-12 86)
raspberrypi-exp-gpio soc:firmware:expgpio: Failed to get GPIO 7 config (-12 87)
spi-bcm2835 3f204000.spi: could not get clk: -517
raspberrypi-exp-gpio soc:firmware:expgpio: Failed to get GPIO 2 config (-12 82)
raspberrypi-exp-gpio soc:firmware:expgpio: Failed to get GPIO 2 config (-12 82)
bcm2835_vchiq 3f00b840.mailbox: could not allocate DMA memory
spi-bcm2835 3f204000.spi: cannot prepare fill_tx_desc - not using DMA mode
sdhost: failed to allocate log buf
After waiting for about 3 minutes, the screen went black and after some more time I eventually got the installation screen to select the language. However, the keyboard and mouse were not working, so I was not able to continue the process. I tried with different USB power sources (all of them 5V and between 2000 mA and 2600 mA), tried the four different USB ports of the Raspberry, and tried connecting only the mouse or only the keyboard. Nothing helped.
I also tried the 64-bit version, also without luck.
Eventually, I gave it a try with version 20.10 (Groovy Gorilla). I followed exactly the same steps, and with this version all problems disappeared.
Unfortunately, since I want to install ROS, I cannot use 20.10. I need version 20.04.2 for that.
Any ideas about why the installation with version 20.04.2 fails?
Is there any way to get that version installed?