[Bug 1847500] [NEW] Full RAM on Pi4 isn't accessible when using u-boot

[Dave Jones]

Public bug reported:

Booting the latest eoan daily on a Pi4 with >1Gb of RAM, only the first
1Gb of RAM appears accessible:

    ubuntu at ubuntu:~$ free
                  total        used        free      shared  buff/cache   available
    Mem:         931920      185484      504748        3664      241688      723820
    Swap:             0           0           0

However, adjusting the config.txt so that the kernel is booted directly
without u-boot in between results in the full 4Gb being accessible:

    ubuntu at ubuntu:~$ free
                  total        used        free      shared  buff/cache   available
    Mem:        3884464      189852     3457504        3656      237108     3636004
    Swap:             0           0           0

** Affects: u-boot (Ubuntu)
     Importance: Undecided
         Status: New

** Description changed:

  Booting the latest eoan daily on a Pi4 with >1Gb of RAM, only the first
  1Gb of RAM appears accessible:
  
- ubuntu at ubuntu:~$ free
-               total        used        free      shared  buff/cache   available
- Mem:         931920      185484      504748        3664      241688      723820
- Swap:             0           0           0
+     ubuntu at ubuntu:~$ free
+                   total        used        free      shared  buff/cache   available
+     Mem:         931920      185484      504748        3664      241688      723820
+     Swap:             0           0           0
  
  However, adjusting the config.txt so that the kernel is booted directly
  without u-boot in between results in the full 4Gb being accessible:
  
- ubuntu at ubuntu:~$ free
-               total        used        free      shared  buff/cache   available
- Mem:        3884464      189852     3457504        3656      237108     3636004
- Swap:             0           0           0
+     ubuntu at ubuntu:~$ free
+                   total        used        free      shared  buff/cache   available
+     Mem:        3884464      189852     3457504        3656      237108     3636004
+     Swap:             0           0           0

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https://bugs.launchpad.net/bugs/1847500

Title:
  Full RAM on Pi4 isn't accessible when using u-boot

Status in u-boot package in Ubuntu:
  New

Bug description:
  Booting the latest eoan daily on a Pi4 with >1Gb of RAM, only the
  first 1Gb of RAM appears accessible:

      ubuntu at ubuntu:~$ free
                    total        used        free      shared  buff/cache   available
      Mem:         931920      185484      504748        3664      241688      723820
      Swap:             0           0           0

  However, adjusting the config.txt so that the kernel is booted
  directly without u-boot in between results in the full 4Gb being
  accessible:

      ubuntu at ubuntu:~$ free
                    total        used        free      shared  buff/cache   available
      Mem:        3884464      189852     3457504        3656      237108     3636004
      Swap:             0           0           0

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