Question about upgrading NetBSD system in RaspberryPi

Hello,

As a NetBSD user on the Raspberry Pi 4  and ZeroW , I realize that every time 
I’m about to update the system, I get really nervous and feel that I am going to 
  make a mistake in the upgrading process.

There are great tools like sysupgrade or sysinst that make it really easy, but 
they only work for upgrading the binary sets. They work very fine for example in 
my AMD64 systems. You do not need to think almost anything, only to point to the 
right URL for downloading...but in raspberrypi it seems different,  I always 
have to think twice what I am doing to do before breaking it. That stress me 
very much.

For example, if we examine the contents of arm64.img.gz file

https://cdn.netbsd.org/pub/NetBSD/NetBSD-11.0_RC4/evbarm-aarch64/binary/gzimg/arm64.img.gz


I see all the following files at /boot partition:


netbsd-raspa4# gunzip arm64.img.gz
netbsd-raspa4# ls
arm64.img
netbsd-raspa4# vndconfig vnd0 arm64.img
netbsd-raspa4# mount /dev/dk2 disco_boot/
netbsd-raspa4# cd disco_boot/
netbsd-raspa4# ls -lh
total 23M
drwxr-xr-x  1 root  users  1.0K May 12 04:23 EFI
-rwxr-xr-x  1 root  users  1.6K May 12 04:23 LICENCE.broadcom
-rwxr-xr-x  1 root  users   51K May 12 04:23 bootcode.bin
-rwxr-xr-x  1 root  users   33B May 12 04:23 cmdline.txt
-rwxr-xr-x  1 root  users  155B May 12 04:23 config.txt
drwxr-xr-x  1 root  users  1.0K May 12 04:23 dtb
-rwxr-xr-x  1 root  users  7.1K May 12 04:23 fixup.dat
-rwxr-xr-x  1 root  users  5.3K May 12 04:23 fixup4.dat
-rwxr-xr-x  1 root  users  3.1K May 12 04:23 fixup4cd.dat
-rwxr-xr-x  1 root  users  3.1K May 12 04:23 fixup_cd.dat
-rwxr-xr-x  1 root  users   16M May 12 04:23 netbsd.img
-rwxr-xr-x  1 root  users  2.8M May 12 04:23 start.elf
-rwxr-xr-x  1 root  users  2.2M May 12 04:23 start4.elf
-rwxr-xr-x  1 root  users  789K May 12 04:23 start4cd.elf
-rwxr-xr-x  1 root  users  789K May 12 04:23 start_cd.elf
netbsd-raspa4#

all those files do not belong to any of the supplied binary sets, so I think 
that the only method to upgrade them is by doing it manually with vndconfig. 
That is the way I always have used to upgrade the system from the beggining.

Just curious to know why is it so difficult. I am sure that there must be 
technical reasons for it to be as is now.


Thanks so much.

Ramiro.