Can I delete some files to achieve same effect like flash userdata.img?

[mhtvsSFrpHdE]

Platform: yoshino Device: maple Kernel version: 4.14 Android version: Android 10 r41 Software binaries version: v11a

Is your feature request related to a problem? Please describe. We know that flash between Android builds may cause require flashing user data to boot,
and that's not handy.

Actually this behavior is very strange because a "user data" should be just "user data",
a system can't require to booting rely on a fresh "user data" every time it's get updated.

Then I guess our kernel may unpack some file into user data partition on first boot,
and will not delete them.
In case a kernel update incompatible with the previous version, it will not delete exist file and unpack new,
it directly used the old files then boot fail.

Here we got the "TWRP" custom recovery images, once boot into the custom recovery,
there is a shell allow to run Linux commands like ls cd rm, so I can delete files in recovery environment.

If I can know what file should be deleted between kernel update, then just delete them,
without erase entire user data partition!

[MartinX3]

fastboot -h

[mhtvsSFrpHdE]

The fastboot -h reports the following...perhaps the fastboot -w ?

usage: fastboot [OPTION...] COMMAND...

flashing:
 update ZIP                 Flash all partitions from an update.zip package.
 flashall                   Flash all partitions from $ANDROID_PRODUCT_OUT.
                            On A/B devices, flashed slot is set as active.
                            Secondary images may be flashed to inactive slot.
 flash PARTITION [FILENAME] Flash given partition, using the image from
                            $ANDROID_PRODUCT_OUT if no filename is given.

basics:
 devices [-l]               List devices in bootloader (-l: with device paths).
 getvar NAME                Display given bootloader variable.
 reboot [bootloader]        Reboot device.

locking/unlocking:
 flashing lock|unlock       Lock/unlock partitions for flashing
 flashing lock_critical|unlock_critical
                            Lock/unlock 'critical' bootloader partitions.
 flashing get_unlock_ability
                            Check whether unlocking is allowed (1) or not(0).

advanced:
 erase PARTITION            Erase a flash partition.
 format[:FS_TYPE[:SIZE]] PARTITION
                            Format a flash partition.
 set_active SLOT            Set the active slot.
 oem [COMMAND...]           Execute OEM-specific command.
 gsi wipe|disable           Wipe or disable a GSI installation (fastbootd only).
 wipe-super [SUPER_EMPTY]   Wipe the super partition. This will reset it to
                            contain an empty set of default dynamic partitions.
 snapshot-update cancel     On devices that support snapshot-based updates, cancel
                            an in-progress update. This may make the device
                            unbootable until it is reflashed.
 snapshot-update merge      On devices that support snapshot-based updates, finish
                            an in-progress update if it is in the "merging"
                            phase.

boot image:
 boot KERNEL [RAMDISK [SECOND]]
                            Download and boot kernel from RAM.
 flash:raw PARTITION KERNEL [RAMDISK [SECOND]]
                            Create boot image and flash it.
 --dtb DTB                  Specify path to DTB for boot image header version 2.
 --cmdline CMDLINE          Override kernel command line.
 --base ADDRESS             Set kernel base address (default: 0x10000000).
 --kernel-offset            Set kernel offset (default: 0x00008000).
 --ramdisk-offset           Set ramdisk offset (default: 0x01000000).
 --tags-offset              Set tags offset (default: 0x00000100).
 --dtb-offset               Set dtb offset (default: 0x01100000).
 --page-size BYTES          Set flash page size (default: 2048).
 --header-version VERSION   Set boot image header version.
 --os-version MAJOR[.MINOR[.PATCH]]
                            Set boot image OS version (default: 0.0.0).
 --os-patch-level YYYY-MM-DD
                            Set boot image OS security patch level.

Android Things:
 stage IN_FILE              Sends given file to stage for the next command.
 get_staged OUT_FILE        Writes data staged by the last command to a file.

options:
 -w                         Wipe userdata.
 -s SERIAL                  Specify a USB device.
 -s tcp|udp:HOST[:PORT]     Specify a network device.
 -S SIZE[K|M|G]             Break into sparse files no larger than SIZE.
 --force                    Force a flash operation that may be unsafe.
 --slot SLOT                Use SLOT; 'all' for both slots, 'other' for
                            non-current slot (default: current active slot).
 --set-active[=SLOT]        Sets the active slot before rebooting.
 --skip-secondary           Don't flash secondary slots in flashall/update.
 --skip-reboot              Don't reboot device after flashing.
 --disable-verity           Sets disable-verity when flashing vbmeta.
 --disable-verification     Sets disable-verification when flashing vbmeta.
 --unbuffered               Don't buffer input or output.
 --verbose, -v              Verbose output.
 --version                  Display version.
 --help, -h                 Show this message.

[MartinX3]

Maaayyybeeeeee

[mhtvsSFrpHdE]

Got it, just flash the userdata.img anyway.