[Sony Xperia XZ1 Compact Guides, News, & Discussion] pbarrette:
What's different in the firmware update..

I did an extract and compare against the UK 324 and 374 versions and came up with a rough list.

The contents of these SIN files are exactly the same:

adspso_X-FLASH-ALL-C93B.sin

amss_fs_1_X-FLASH-ALL-C93B.sin

amss_fs_2_X-FLASH-ALL-C93B.sin

appslog_X-FLASH-ALL-C93B.sin

bluetooth_X-FLASH-ALL-C93B.sin

bootloader_X_BOOT_MSM8998_LA1_1_O_77_X-FLASH-ALL-C93B.sin (all boot SINs, actually, but this is the one that gets loaded)

cache_X-FLASH-ALL-C93B.sin

diag_X-FLASH-ALL-C93B.sin

fsmetadata_X-FLASH-ALL-C93B.sin

ramdump_X-FLASH-ALL-C93B.sin

ssd_X-FLASH-ALL-C93B.sin

persist_X-FLASH-ALL-C93B.sin

Qnovo_X-FLASH-ALL-C93B.sin

userdata_X-FLASH-ALL-C93B.sin

All *.ta files are the same.

Now for the differences.

amss_fsg_X-FLASH-ALL-C93B.sin:

MCC 240 was moved from the [mcc_list name="eu_b4_mccs"] config to a new [mcc_list name="swe_mccs"] config.

elabel-G8441-row-row_201709190503668.1_47.1.A.2.374_X-FLASH-LTALABEL-C93B.sin:

Added a regulatory label for Malaysia.

fotakernel_X-FLASH-ALL-C93B.sin (Ramdisk only, didn't extract the kernel):

crashtag specifies new firmware version

sepolicy bits changed

prop.default has "ro.setupwizard.rotation_locked=false" added

kernel_X-FLASH-ALL-C93B.sin (Ramdisk only, didn't extract the kernel):

crashtag specifies new firmware version

sepolicy bits changed

init.sony-platform.rc had this line removed: setprop persist.bluetooth.btsnooppath "/sdcard/btsnoop_hci.log"

modem_X-FLASH-ALL-C93B.sin:

Changed audio, modem, qdsp6m, and sensor blobs

oem_X-FLASH-ALL-C93B.sin:

"ssid=_The Cloud X" added to preset_networks.conf

APN updates

"com.amazon.avod.thirdpartyclient.apk" added

ee_ims & telefonica specific modem configs added

Overlay APK changes (I didn't check the changes)

Version & region changes (R8B->R12B)

system_X-FLASH-ALL-C93B.sin:

/app/[lots changed, haven't extracted]

/bin/dnsmasq changed

/bin/customization/modem/* changed

/etc/firmware/(I honestly can't tell if it's a real change or just recompile changes)

/etc/permissions/privapp-permissions-google.xml added: permission name="android.permission.DISPATCH_PROVISIONING_MESSAGE"

/framework/(all oat, odex, art changed, no vdex's were changed except: boot-framework.vdex, boot-ims-common.vdex, boot-telephony-common.vdex)

/framework/framework-res.apk changed

/lib/hw/bluetooth.default.so changed

/lib/modules/* (I honestly can't tell if it's a real change or just recompile changes)

/lib/libandroid_runtime.so, libaudioflinger.so, libmediaplayerservice.so, libminikin.so, libpdfium.so, libsqlite.so, libstagefright.so, libstagefright_foundation.so, libstagefright_soft_avcdec.so, libvorbisidec.so

/lib64/hw/bluetooth.default.so

/lib64/libandroid_runtime.so, libaudioflinger.so, libdeqp_somc.so, libmediaplayerservice.so, libminikin.so, libnfc-nci.so, libpdfium.so, libsqlite.so, libstagefright.so, libstagefright_foundation.so, libstagefright_soft_avcdec.so, libvorbisidec.so

/priv-app/[lots changed, haven't extracted]

build.prop -> "ro.expect.recovery_id"

vendor_X-FLASH-ALL-C93B.sin:

/app/[lots change, haven't extracted],

/bin/hw/illumination_service

/bin/sct_service, sensors.qcom, updatemiscta

/etc/permissions/handheld_core_hardware.xml added

/etc/sepolicy/[files] some changes

/lib/camera/libexcal_multiframe_nr_plugin.so, libexcal_snapshot_ctrl_plugin.so

/lib/modules/qca_cld3_wlan.ko

/lib/soundfx/libdownmix.so, libreverbwrapper.so

/lib/libcammw.so, libexcal_system.so (face and object tracking?), libmmcamera2_iface_modules.so, libmmcamera2_imglib_modules.so, libmmcamera2_mct.so, libmmcamera2_sensor_modules.so, libmmcamera2_stats_modules.so, libOmxVenc.so, libpf.so (OMX video related), libril-qc-qmi-1.so

/lib64/soundfx/libdownmix.so, libreverbwrapper.so,

/lib64/libpf.so, libril-qc-qmi-1.so

build date changed

ro.setupwizard.rotation_locked=false added to props

There might be bits that I missed in the changed SINs, but the unchanged ones are unchanged.

Bear in mind that with the split firmware bits, sometimes it's difficult to determine if, say, "tzsuntory.b01" was actually changed, or if it was just a header difference due to a recompile. So I'm just ignoring the ones that I "think" are the same. That said, if I'm ignoring it, it's because it was contained in a SIN file that has other changes as well.

EDIT: I forgot to add that

userdata_X-FLASH-ALL-C93B.sin

is also unchanged.