** Description changed:

  Impact:
  
  Overlay files are dtb fragments that, upon boot, patch the main dtb board
- file to enable Raspberry Pi board hardware extension commonly know as
- Raspberry HATs.
+ file to enable Raspberry Pi hardware extension (commonly known as
+ Raspberry HATs) to work.
  
- This mechanism works fine for the bionic/raspi2 kernel, while it didn't
+ This mechanism works fine for the bionic/raspi2 kernel, but it didn't
  work for the raspi2 arm64 variant since our dtb files are missing symbols
  there.
  
- This patch instruct the device tree compiler to add symbols to the dtb
- files during the 'make dtbs' target, and fix overlay patching for
- bionic/raspi2 arm64.
+ This patch instruct the device tree compiler to add symbols to the dtb 
+ files during the 'make dtbs' target, and fix the overlay patching 
+ mechanism for bionic/raspi2 arm64.
  
- The resulting increase is size is negligible (~30kb for the whole kernel
+ The resulting increase in size is negligible (~30kb for the whole kernel
  package).
  
  Fix:
  
  Apply the patch, build, install and reboot:
  
  /boot/firmware/config.txt:
  ...
  dtoverlay=pitft35-resistive
  
  /boot/firmware/cmdline.txt:
  dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=/dev/mmcblk0p2 
rootfstype=ext4 elevator=deadline rootwait fbcon=map:10 fbcon=font:VGA8x8
- 
  
  dmesg:
  ...
  [    5.157547] fb_hx8357d: module is from the staging directory, the quality 
is unknown, you have been warned.
  [    5.158349] fbtft_of_value: buswidth = 8
  [    5.158362] fbtft_of_value: debug = 0
  [    5.158366] fbtft_of_value: rotate = 90
  [    5.158372] fbtft_of_value: fps = 25
  
  ubuntu@raspi64:~$ ls -la /dev/fb1
  crw-rw---- 1 root video 29, 1 Jan 28 15:58 /dev/fb1
  
  Regression risk:
  
  We only change how the arm64 raspi2 dtbs are generated, and since we
  didn't produce any image using this kernel so far, the regression risk
  is zero.
  
  ---

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https://bugs.launchpad.net/bugs/1782121

Title:
  arm64: overlays don't get applied

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