Recompile the kernel with the option “High Memory Support 64G” turned on.
Symbol: HIGHMEM64G [=y]
│ Prompt: 64GB
│ Defined at arch/i386/Kconfig:538
│ Depends on: <choice> && X86_CMPXCHG64
│ Location:
│ -> Processor type and features
│ -> High Memory Support (<choice> [=y])