zero_derivative

Yes - I can confirm that the C2 take some time before I can ssh into it... but with normal armbian
 
Debian Buster with Armbian Linux 5.3.0-meson64
package bsp-kernel[5.97.190917] u-boot[5.96] dtb[5.97.190917] firmware[5.96] config[5.96]
 
it took me around 2-3 minutes.
 
After your info about the entropy pool I did found firstly the following page which also suggest havegd:
https://daniel-lange.com/archives/152-Openssh-taking-minutes-to-become-available,-booting-takes-half-an-hour-...-because-your-server-waits-for-a-few-bytes-of-randomness.html
 
But this on my mind,  I compared my NanoPi Neo2 with the C2
 
NanoPi Neo2:
dmesg | grep -E "(rng|random)" [ 0.000000] random: get_random_bytes called from start_kernel+0x2e4/0x478 with crng_init=0 [ 5.888987] random: fast init done [ 7.924082] random: systemd: uninitialized urandom read (16 bytes read) [ 7.933060] random: systemd: uninitialized urandom read (16 bytes read) [ 7.945521] random: systemd: uninitialized urandom read (16 bytes read) [ 11.610613] random: crng init done [ 11.610625] random: 7 urandom warning(s) missed due to ratelimiting Odroid C2:
dmesg | grep -E "(rng|random)" [ 0.000000] random: get_random_bytes called from start_kernel+0x2f4/0x488 with crng_init=0 [ 4.708300] random: fast init done [ 6.124106] random: systemd: uninitialized urandom read (16 bytes read) [ 6.131317] random: systemd: uninitialized urandom read (16 bytes read) [ 6.132394] random: systemd: uninitialized urandom read (16 bytes read) [ 84.643984] random: crng init done [ 84.643999] random: 7 urandom warning(s) missed due to ratelimiting So a hugh difference between 11 and 84 in counting,
 
As I only got this problem on the Odroid C2 (Amlogic S905) and my Sunvell T95K Pro (Amlogic S912) I searched for a
Amlogic-CPU-Solution and did found the following for the Ordoid C1 (Amlogic S805):
 
[FIXED] Random Number Generator on odroid-c1 ==> Hardware Random Number Generator Accelerator
https://forum.odroid.com/viewtopic.php?f=115&t=8874
https://odroid.com/dokuwiki/doku.php?id=en:c1_hardware_number_generator
 
You have to install rng-tools:
apt-cache search rng-tools rng-tools - Daemon to use a Hardware TRNG rng-tools-debian - daemon to use a Hardware TRNG (classic version) rng-tools5 - Daemon to use a Hardware TRNG sudo apt-get install rng-tools After I did install the rng-tools I could immediately ssh into my C2 then the /etc/rc.local was processed
(do get a voice info on my system).
 
The time to fill the entropy pool is now with 12 as short as on the NanoPi Neo2
dmesg | grep -E "(rng|random)" [ 0.000000] random: get_random_bytes called from start_kernel+0x2f4/0x488 with crng_init=0 [ 4.684192] random: fast init done [ 6.221509] random: systemd: uninitialized urandom read (16 bytes read) [ 6.229215] random: systemd: uninitialized urandom read (16 bytes read) [ 6.230358] random: systemd: uninitialized urandom read (16 bytes read) [ 12.413199] random: crng init done [ 12.413207] random: 7 urandom warning(s) missed due to ratelimiting @zero_derivative Thanks for the info about the entropy pool!
@Igor maybe rng-tools should be an default installed packet on amlogic-devices?
@balbes150 maybe also some users of your Amlogic-images would like this

FWIW My boot delays were much more drastic and consistent across 6 Odroid C2's initially using the minimal image ...
dmesg | grep -E "(rng|random)" [ 0.000000] random: get_random_bytes called from start_kernel+0xa8/0x400 with crng_init=0 [ 3.074316] random: fast init done [ 4.216928] random: systemd: uninitialized urandom read (16 bytes read) [ 4.220823] random: systemd: uninitialized urandom read (16 bytes read) [ 4.221479] random: systemd: uninitialized urandom read (16 bytes read) [ 1846.057161] random: crng init done [ 1846.057175] random: 7 urandom warning(s) missed due to ratelimiting My Odroid C2's also show a ridiculously low amount (single to low double digits) of available entropy without haveged and the rate at which available entropy increases is very very very slow ...
cat /proc/sys/kernel/random/entropy_avail 5  
With haveged it's marginally better, and the rate at which available entropy increases is better than without out it, but still too slow  ...
cat /proc/sys/kernel/random/entropy_avail 77  
With rng-tools installed things are looking much better ...
cat /proc/sys/kernel/random/entropy_avail 2002 and now SSH is available much quicker ...
dmesg | grep -E "(rng|random)" [ 0.000000] random: get_random_bytes called from start_kernel+0xa8/0x400 with crng_init=0 [ 2.954319] random: fast init done [ 4.298379] random: systemd: uninitialized urandom read (16 bytes read) [ 4.308032] random: systemd: uninitialized urandom read (16 bytes read) [ 4.309349] random: systemd: uninitialized urandom read (16 bytes read) [ 10.320571] random: crng init done [ 10.320579] random: 7 urandom warning(s) missed due to ratelimiting Awesome!
 
Thanks @guidol for the rng-tools tip