Convert Chromium OS image?

[toconquer]

Hi I've been working to try to convert Chromium OS to BerryBoot image.
root@server:/home/user# kpartx -av chromiumos_image_r92r2-rpi4b.img add map loop7p1 (253:1): 0 8388717 linear 7:7 4612096 add map loop7p2 (253:2): 0 49152 linear 7:7 20480 add map loop7p3 (253:3): 0 4194304 linear 7:7 417792 add map loop7p4 (253:4): 0 49152 linear 7:7 69632 add map loop7p5 (253:5): 0 4096 linear 7:7 413696 add map loop7p6 (253:6): 0 1 linear 7:7 16448 add map loop7p7 (253:7): 0 1 linear 7:7 16449 add map loop7p8 (253:8): 0 32768 linear 7:7 118784 add map loop7p9 (253:9): 0 1 linear 7:7 16450 add map loop7p10 (253:10): 0 1 linear 7:7 16451 add map loop7p11 (253:11): 0 16384 linear 7:7 64 add map loop7p12 (253:12): 0 131072 linear 7:7 282624

It's creating a tiny .img file as output, only 4k.

[symbios24]

Chromium cannot be converted due to many partitions it has

[dismal002]

Could the image be extracted then each partition be converted?

[symbios24]

Extracted yes with 7zip,i dont know about the second