[Samsung Galaxy Watch] adfree:
Lets do some research... :D

I am trying to share what I "know" about FOTA Delta... as example we can take the file from post

https://xdaforums.com/showpost.php?p=83630995&postcount=12

A

Last "2 KB" in Delta TAR we can find Signature... Certs blabla...

Readable Text String:

signed by SignApk

We can ignore this... ;)

B

Files inside... it is small update... so only few files. :good:

cm.bin
csc.img
delta.boot
delta.ramdisk1
delta.ramdisk2
delta.recovery
delta.ua
delta.upparam
rootfs.img
sboot.bin
unpack.sh
update.cfg
csc.img\CSC.txt
csc.img\CSC_attr.txt
csc.img\diff1_NaverMap.wgt_CSC.delta
csc.img\diff2_Spotify.tpk_CSC.delta
csc.img\diff3_TizenFontKaitiChina.wgt_CSC.delta
csc.img\diff4_com_samsung_health_samd_bp.tpk_CSC.delta
csc.img\diff5_SW_Configuration.xml_CSC.delta
rootfs.img\diff10_tizen-release_ROOTFS.delta
rootfs.img\diff11_slp-release.repo_ROOTFS.delta
rootfs.img\diff12_tizen-wearable-standard-snapshot.repo_ROOTFS.delta
rootfs.img\diff13_.restore_exception.list_ROOTFS.delta
rootfs.img\diff14_author-signature.xml_ROOTFS.delta
rootfs.img\diff15_add_viewer_wrap.edj_ROOTFS.delta
rootfs.img\diff16_apps_item.edj_ROOTFS.delta
rootfs.img\diff17_apps_layout.edj_ROOTFS.delta
rootfs.img\diff18_apps_page.edj_ROOTFS.delta
rootfs.img\diff19_apps_view_layout.edj_ROOTFS.delta
rootfs.img\diff1_memory.db-journal_ROOTFS.delta
rootfs.img\diff20_clock_contextual.edj_ROOTFS.delta
rootfs.img\diff21_clock_indicator.edj_ROOTFS.delta
rootfs.img\diff22_dashboard.edj_ROOTFS.delta
rootfs.img\diff23_edit.edj_ROOTFS.delta
rootfs.img\diff24_layout.edj_ROOTFS.delta
rootfs.img\diff25_page.edj_ROOTFS.delta
rootfs.img\diff26_page_clock.edj_ROOTFS.delta
rootfs.img\diff27_page_indicator.edj_ROOTFS.delta
rootfs.img\diff28_preview.edj_ROOTFS.delta
rootfs.img\diff29_scrollView.edj_ROOTFS.delta
rootfs.img\diff2_system.db-journal_ROOTFS.delta
rootfs.img\diff30_tutorial.edj_ROOTFS.delta
rootfs.img\diff31_tutorial_steps.edj_ROOTFS.delta
rootfs.img\diff32_signature1.xml_ROOTFS.delta
rootfs.img\diff33_author-signature.xml_ROOTFS.delta
rootfs.img\diff34_windicator.edj_ROOTFS.delta
rootfs.img\diff35_signature1.xml_ROOTFS.delta
rootfs.img\diff36_ffffffff00000000000000000000000a.tlbin_ROOTFS.delta
rootfs.img\diff37_ffffffff00000000000000000000000b.tlbin_ROOTFS.delta
rootfs.img\diff38_author-signature.xml_ROOTFS.delta
rootfs.img\diff39_wc-popup_ROOTFS.delta
rootfs.img\diff3_device-sec-policy_ROOTFS.delta
rootfs.img\diff40_signature1.xml_ROOTFS.delta
rootfs.img\diff41_sapd_ROOTFS.delta
rootfs.img\diff42_scsd_ROOTFS.delta
rootfs.img\diff43_test_scs_ROOTFS.delta
rootfs.img\diff44_weconnd_ROOTFS.delta
rootfs.img\diff45_libsap-client-stub-api.so.1.0.0_ROOTFS.delta
rootfs.img\diff46_libsap_client.so.0.0.0_ROOTFS.delta
rootfs.img\diff47_libweconn.so.4.1.7_ROOTFS.delta
rootfs.img\diff48_locale-archive_ROOTFS.delta
rootfs.img\diff49_ble.so_ROOTFS.delta
rootfs.img\diff4_info.ini_ROOTFS.delta
rootfs.img\diff50_bt.so_ROOTFS.delta
rootfs.img\diff51_scs.so_ROOTFS.delta
rootfs.img\diff52_tcp.so_ROOTFS.delta
rootfs.img\diff53_sap.service_ROOTFS.delta
rootfs.img\diff54_weconn.service_ROOTFS.delta
rootfs.img\diff55_mod_bt.so_ROOTFS.delta
rootfs.img\diff56_mod_cellular.so_ROOTFS.delta
rootfs.img\diff57_mod_p2p.so_ROOTFS.delta
rootfs.img\diff58_mod_sap.so_ROOTFS.delta
rootfs.img\diff59_mod_wifi.so_ROOTFS.delta
rootfs.img\diff5_os-release_ROOTFS.delta
rootfs.img\diff60_removed-file.lst_ROOTFS.delta
rootfs.img\diff61_privilege-mount.list_ROOTFS.delta
rootfs.img\diff62_usr_share_locale.squash_ROOTFS.delta
rootfs.img\diff63_resource_QNX.zip_ROOTFS.delta
rootfs.img\diff64_checksum.md5_ROOTFS.delta
rootfs.img\diff65_opt.zip_ROOTFS.delta
rootfs.img\diff66_smack_label.txt_ROOTFS.delta
rootfs.img\diff67_ugid_permission.txt_ROOTFS.delta
rootfs.img\diff68_libsap.so.1.12.0_ROOTFS.delta
rootfs.img\diff6_system_info_db_ROOTFS.delta
rootfs.img\diff7_kern_sec_info_ROOTFS.delta
rootfs.img\diff8_tima_measurement_info_ROOTFS.delta
rootfs.img\diff9_tizen-build.conf_ROOTFS.delta
rootfs.img\ROOTFS.txt
rootfs.img\ROOTFS_attr.txt

C

cm.bin
sboot.bin

Bootloader and Bootloader related file are ever 100 % full Image... FULL_IMG

D

update.cfg

Here we can see Partition Table Infos... MD5 Hashes...

BOOTLOADER	sboot.bin	[B]FULL_IMG[/B]	/dev/mmcblk0p80	0	1921296	1921296	2e2f2c95b6c79f9499a6b1ecb2d8f4a5a434b505	9d4493e96538835f75e13510da6696bd102bb9b3
CM	cm.bin	[B]FULL_IMG[/B]	/dev/mmcblk0p11	0	2597136	2597136	48041a45e24bb1d8490e0a11c00ce5e57826e0ef	aa43a94670a4ea3aa13b5b514c59cf3a83e47568
ROOTFS	rootfs.img/	DELTA_FS	/dev/mmcblk0p19	0	58207558
CSC	csc.img/	DELTA_FS	/dev/mmcblk0p16	0	17828390
BOOT	delta.boot	DELTA_IMG	/dev/mmcblk0p12	0	15524112	15524112	da8ecde6d6b4a048342f381765f552d39cfdd793	fadeb71ce42d2b727b8e5840234b01cf2d8e60c7
UP_PARAM	delta.upparam	DELTA_IMG	/dev/mmcblk0p10	0	1085440	1085440	8f66a3a59b1685c9d043d9ad1df0627a85c475ed	043ae8dda424a2e9433471264201c8eb73390c79
RAMDISK1	delta.ramdisk1	DELTA_IMG	/dev/mmcblk0p8	0	7340304	7340304	22af46f1186e2d63bc688ef6271fab634ca15ee6	ccf7859cd5ec61d849626fe9eae8b11ca7c8427f
RAMDISK2	delta.ramdisk2	EXTRA	/dev/mmcblk0p7	0	19923216	19923216	5822281d04ac49dbb1f413acf150049533bcf758	c1161d9abedc468e0bb8a9dbeb014cee24c733a3
RECOVERY	delta.recovery	EXTRA	/dev/mmcblk0p13	0

We can see the 3 types:

FULL_IMG
DELTA_IMG
DELTA_FS

IMG means files we know from Firmware packages...

FS IMHO Filesystem... affected csc.img and rootfs.img

E

delta.ua

This File is allready in Firmware... but newer Versions comes with delta.tar ...

Seems main part of FOTA procedure...

Best Regards