[Redmi Note 9 Questions & Answers] Namekinek0:
Ok, now I'm completely stuck. I managed to extract from the boot.img what I think is the kernel image, it's now in prebuilt/zImage. But I got a problem with the recovery.fstab I should write. The problem is that I cannot find /system mounted. Could it be that the problem is that Magisk is installed and it messes up something? Please help me. Could it be that the mount address is /dev/block/dm-1/system?

poly@poly-PC:~$ adb shell
merlinnfc:/ $ su
merlinnfc:/ # mount -o ro,remount /
merlinnfc:/ # mount -o ro,remount /system
mount: '/system' not in /proc/mounts
1|merlinnfc:/ # mount -o ro,mount /system
mount: bad /etc/fstab: No such file or directory
1|merlinnfc:/ # mount
/dev/block/dm-1 on / type ext4 (ro,seclabel,relatime)
tmpfs on /dev type tmpfs (rw,seclabel,nosuid,relatime,size=1921708k,nr_inodes=480427,mode=755)
devpts on /dev/pts type devpts (rw,seclabel,relatime,mode=600,ptmxmode=000)
proc on /proc type proc (rw,relatime,gid=3009,hidepid=2)
sysfs on /sys type sysfs (rw,seclabel,relatime)
selinuxfs on /sys/fs/selinux type selinuxfs (rw,relatime)
tmpfs on /mnt type tmpfs (rw,seclabel,nosuid,nodev,noexec,relatime,size=1921708k,nr_inodes=480427,mode=755,gid=1000)
tmpfs on /apex type tmpfs (rw,seclabel,nosuid,nodev,noexec,relatime,size=1921708k,nr_inodes=480427,mode=755)
/dev/block/mmcblk0p9 on /metadata type ext4 (rw,seclabel,nosuid,nodev,noatime,discard,data=ordered)
/dev/block/dm-2 on /vendor type ext4 (ro,seclabel,relatime)
/dev/block/dm-0 on /product type ext4 (ro,seclabel,relatime)
tmpfs on /sbin type tmpfs (rw,seclabel,relatime,size=1921708k,nr_inodes=480427,mode=755)
/sbin/.magisk/block/persist on /sbin/.magisk/mirror/persist type ext4 (rw,seclabel,relatime,data=ordered)
/sbin/.magisk/block/system_root on /sbin/.magisk/mirror/system_root type ext4 (ro,seclabel,relatime)
/sbin/.magisk/block/system_root on /sbin/setlockstate type ext4 (ro,seclabel,relatime)
none on /dev/cg2_bpf type cgroup2 (rw,nosuid,nodev,noexec,relatime)
none on /dev/cpuctl type cgroup (rw,nosuid,nodev,noexec,relatime,cpu)
none on /acct type cgroup (rw,nosuid,nodev,noexec,relatime,cpuacct)
none on /dev/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset,noprefix,release_agent=/sbin/cpuset_release_agent)
none on /dev/memcg type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
none on /dev/stune type cgroup (rw,nosuid,nodev,noexec,relatime,schedtune)
debugfs on /sys/kernel/debug type debugfs (rw,seclabel,relatime)
tracefs on /sys/kernel/debug/tracing type tracefs (rw,seclabel,relatime)
none on /config type configfs (rw,nosuid,nodev,noexec,relatime)
bpf on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,relatime)
pstore on /sys/fs/pstore type pstore (rw,seclabel,nosuid,nodev,noexec,relatime)
none on /sys/fs/cgroup type tmpfs (rw,seclabel,relatime,size=1921708k,nr_inodes=480427,mode=750,gid=1000)
none on /sys/fs/cgroup/memory type cgroup (rw,relatime,memory)
none on /sys/fs/cgroup/freezer type cgroup (rw,relatime,freezer)
/dev/block/mmcblk0p46 on /data type ext4 (rw,seclabel,nosuid,nodev,noatime,noauto_da_alloc,resuid=10010,resgid=1065,errors=panic,data=ordered)
/dev/block/mmcblk0p45 on /cache type ext4 (rw,seclabel,nosuid,nodev,noatime,discard,noauto_da_alloc,data=ordered)
/dev/block/mmcblk0p15 on /mnt/vendor/protect_f type ext4 (rw,seclabel,nosuid,nodev,noatime,nodelalloc,noauto_da_alloc,commit=1,data=ordered)
/dev/block/mmcblk0p16 on /mnt/vendor/protect_s type ext4 (rw,seclabel,nosuid,nodev,noatime,nodelalloc,noauto_da_alloc,commit=1,data=ordered)
/dev/block/mmcblk0p12 on /mnt/vendor/nvdata type ext4 (rw,seclabel,nosuid,nodev,noatime,discard,noauto_da_alloc,data=ordered)
/dev/block/mmcblk0p11 on /mnt/vendor/nvcfg type ext4 (rw,seclabel,nosuid,nodev,noatime,nodelalloc,noauto_da_alloc,commit=1,data=ordered)
/dev/block/mmcblk0p13 on /mnt/vendor/persist type ext4 (rw,seclabel,nosuid,nodev,noatime,data=ordered)
/dev/block/mmcblk0p41 on /cust type ext4 (ro,seclabel,nosuid,nodev,noatime,data=ordered)
tmpfs on /storage type tmpfs (rw,seclabel,nosuid,nodev,noexec,relatime,size=1921708k,nr_inodes=480427,mode=755,gid=1000)
adb on /dev/usb-ffs/adb type functionfs (rw,relatime)
/dev/block/loop2 on /apex/com.android.tzdata@292500001 type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop2 on /apex/com.android.tzdata type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop3 on /apex/com.android.media@292000301 type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop3 on /apex/com.android.media type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop4 on /apex/com.android.resolv@290000000 type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop4 on /apex/com.android.resolv type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop5 on /apex/com.android.conscrypt@290000000 type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop5 on /apex/com.android.conscrypt type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop6 on /apex/com.android.runtime@1 type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop6 on /apex/com.android.runtime type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop7 on /apex/com.android.apex.cts.shim@1 type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop7 on /apex/com.android.apex.cts.shim type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop8 on /apex/com.android.media.swcodec@292200001 type ext4 (ro,dirsync,seclabel,nodev,noatime)
/dev/block/loop8 on /apex/com.android.media.swcodec type ext4 (ro,dirsync,seclabel,nodev,noatime)
/sbin/.magisk/block/vendor on /sbin/.magisk/mirror/vendor type ext4 (ro,seclabel,relatime)
/sbin/.magisk/block/product on /sbin/.magisk/mirror/product type ext4 (ro,seclabel,relatime)
/sbin/.magisk/block/data on /sbin/.magisk/mirror/data type ext4 (rw,seclabel,relatime,noauto_da_alloc,resuid=10010,resgid=1065,errors=panic,data=ordered)
/sbin/.magisk/block/data on /sbin/.magisk/modules type ext4 (rw,seclabel,relatime,noauto_da_alloc,resuid=10010,resgid=1065,errors=panic,data=ordered)
/data/media on /mnt/runtime/default/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=1015,multiuser,mask=6,derive_gid,default_normal)
/data/media on /storage/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=1015,multiuser,mask=6,derive_gid,default_normal)
/data/media on /mnt/runtime/read/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,multiuser,mask=23,derive_gid,default_normal)
/data/media on /mnt/runtime/write/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,multiuser,mask=7,derive_gid,default_normal)
/data/media on /mnt/runtime/full/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,multiuser,mask=7,derive_gid,default_normal)
/dev/block/vold/public:179,129 on /mnt/media_rw/A246-600F type exfat (rw,dirsync,nosuid,nodev,noexec,noatime,uid=1023,gid=1023,fmask=0007,dmask=0007,allow_utime=0020,iocharset=utf8,namecase=0,errors=remount-ro)
/mnt/media_rw/A246-600F on /mnt/runtime/default/A246-600F type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=1015,mask=6)
/mnt/media_rw/A246-600F on /storage/A246-600F type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=1015,mask=6)
/mnt/media_rw/A246-600F on /mnt/runtime/read/A246-600F type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,mask=18)
/mnt/media_rw/A246-600F on /mnt/runtime/write/A246-600F type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,mask=18)
/mnt/media_rw/A246-600F on /mnt/runtime/full/A246-600F type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=9997,mask=7)