hi meo,
this time-consuming problem was also mine.
After writing a picore-14.0.zip on a 32GiB mmc using balena-etcher, the mmc was booting fine on my rasp4 (first downloading all of the ssh keys).
Then to mount the fat32 partition:
tc@box:~$ mount /dev/mmcblk0p1
and to scroll and read.
tc@box:~$ less /mnt/mmcblk0p1/README
It covers all of the steps to follow, but this is not easy for people with visual impairments like me, so I re-formatted it to fit on my display, so that its possible to tce-load -iw all of the extensions I need.
However, trying a 32GiB USB-stick instead I was stopped,- no way to access the stick and write to it permanently.
After some search I found that for USB-Sticks I need to add a waitusb=5 to sdb1/cmdline.txt.
This is also the right file to add a tz=GMT-2 for MET timezone and desktop=jwm if you are using jwm.tcz
Now I have both a mmc and a pendrive to boot on a RasPi4, each for 32Bit and 64Bit.
Next problem.
On piCore14.0-32 I can install and run firefox.tcz (I'm actually writing this post too), version 68.0.5esr-32bit. A bit old, but it works for me.
On piCore14.0-64 I can install firefox.tcz too, but it will not run and only throws back this error message:
tc@box:~$ firefox
XPCOMGlueLoad error for file /tmp/tcloop/firefox/usr/local/lib/firefox/libxul.so:
libffi.so.7: cannot open shared object file: no such file or directory
Couldn't load XPCOM.
tc@box:~$
On piCore13.1 firefox is running fine on both 32Bit and 64Bit.
Thanks in advance