Firebird 5 compiling on Oracle Linux 8 Ampere V1 (arm64)

You can compile just fine Firebird 4/5 on Oracle Linux 8 Ampere V1 (arm64) all you need is GCC Toolset 12 enabled as described here .

Also same steps work for Oracle Linux 8.x on x86-64. 

sudo dnf group install "Development Tools"
sudo dnf install libicu-devel cmake git 
sudo dnf install gcc-toolset-12
scl enable gcc-toolset-12 bash

git clone https://github.com/FirebirdSQL/firebird.git
cd firebird
./configure --with-builtin-tommath --with-builtin-tomcrypt
make