How to generate SPIFFS image externally?

hm… I was happy too early… could not add the 6th file

Now I add “chi.hex” file size 148656 bytes in the “chi” folder and uses docker command to generate “chi.bin”

$ docker run -v $(pwd):$(pwd) -t mgos/esp8266-build:2.2.1-1.5.0-r5 mkspiffs -s 524288 -b 4096 $(pwd)/chi -f $(pwd)/src/chi.bin

     FS params: size=524288, bs=4096, ps=256, es=4096
       Adding apple-icon-180x180.png: 12038
       Adding favicon.ico: 2238
       Adding android-icon-192x192.png: 12785
       Adding chi_smart_114x114.png: 8289
       Adding chi.hex: 148656
       Adding index.html: 33536
     FS stats : space total=474641, used=220880, free=253761

But after build, flash via uart, reset

mgos_vfs.c:147          /chi: SPIFFS @ data, opts {"bs": 4096, "es": 4096}
mgos_vfs.c:320          /chi: size 474641, used: 213852, free: 260789

The used size differ!

using $ mos --port ws://ip/rpc ls -l chi

android-icon-192x192.png 12785
apple-icon-180x180.png 12038
chi_smart_114x114.png 8289
favicon.ico 2238
index.html 33536

The file “chi.hex” did not present. However, I could use the “mos put” command to put the chi.hex file in chi folder.

Where could be the issues?