This is because you're searching for an x86_64 cpuflag in /proc/cpuinfo, which... does not exist on arm64/aarch64. Unfortunately, there isn't a cpuinfo flag that specifies 64bit on arm64.
There are a few ways...
You could grep dmesg output -
systemd spits out :
Code:
[ 3.872742] systemd[1]: Detected architecture arm64.
uname -a will have v8 in the name:
Code:
Linux rpi4 4.19.93-Re4son-v8l+ #1 SMP PREEMPT Tue Jan 7 22:53:24 UTC 2020 aarch64 GNU/Linux
You could also check the bash binary via "file" if you wanted to:
Code:
root@rpi4:~# file /bin/bash
/bin/bash: ELF 64-bit LSB pie executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-a
arch64.so.1, BuildID[sha1]=3951fd7c1824802b0203cfb7863bad8f9d11dab8, for GNU/Linux 3.7.0, stripped