I will try to answer all your questions.
0/ Yes I "dd"-ed the original SD card and "dd"-ed the image on the new one.
1/ Yes.
(check full res here:
https://imgur.com/a/p8Rg8PZ )
This is the monitor.app file from 5.14_1225 firmware for TL2/626.
So modified "/sys/block/mmcblk%c/device/serial" to "/mnt/secure/.sd_original_serial" (check screenshot, padded with a null byte).
2&3/ The ".sd_original_serial" was creating with the following command:
echo 0xaabbccdd > .sd_original_serial
When I have the SD in my computer, it is like that:
Code:
Disk /dev/sdd: 14.7 GiB, 15720251392 bytes, 30703616 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x0a706388
Device Boot Start End Sectors Size Id Type
/dev/sdd1 1009664 28606462 27596799 13.2G b W95 FAT32
/dev/sdd2 * 73728 139263 65536 32M 6 FAT16
/dev/sdd3 1 1009664 1009664 493M 85 Linux extended
/dev/sdd4 28606464 30703615 2097152 1G 83 Linux
/dev/sdd5 139264 172031 32768 16M 83 Linux
/dev/sdd6 172032 204799 32768 16M 83 Linux
/dev/sdd7 204800 275455 70656 34.5M 83 Linux
/dev/sdd8 275456 776191 500736 244.5M 83 Linux
/dev/sdd9 776192 976895 200704 98M 83 Linux
/dev/sdd10 976896 1009663 32768 16M 83 Linux
/dev/sdd1 is the "user" partition
/dev/sdd2 is the boot partition (with what I guess is the kernel etc.)
/dev/sdd7 is the root partition (with /etc, linux userland)
/dev/sdd8 is ebrmain (it contains cramfs.img which in turn contains actual pocketbook programs like monitor.app, can be extracted with cramfsck).
/dev/sdd9 is the "secure" partition, mounted as /mnt/secure on pocketbook.
This is where I put the .sd_original_serial file.
Code:
root@kali:/media/root/90ea7483-25c1-48ae-937c-b39d3b60b4e3# df -k .
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sdd9 97167 19473 72677 22% /media/root/90ea7483-25c1-48ae-937c-b39d3b60b4e3
root@kali:/media/root/90ea7483-25c1-48ae-937c-b39d3b60b4e3# ls -lA
total 1314
-rw-r--r-- 1 root root 779270 Jul 11 2014 bootlogo.bmp
-rw-rw-rw- 1 systemd-resolve systemd-timesync 0 Jul 8 11:01 device.cfg
-rw-rw-rw- 1 root root 32 Jul 11 2014 deviceid
drwxrwx--- 2 systemd-resolve systemd-timesync 1024 Jul 5 16:08 dictionaries
-rw-r--r-- 1 root root 524288 Jul 11 2014 explorer-2.tar
-r-------- 1 root root 4 Jan 1 2000 .freezestatus
-rwxr-xr-x 1 root root 196 Jul 11 2014 fwinfo.txt
-rw-rw---- 1 systemd-resolve systemd-timesync 51 Jul 5 16:10 global.cfg
-rw-rw-rw- 1 systemd-resolve systemd-timesync 16 Jul 11 2014 .hashsum_1
-rw-r--r-- 1 root root 16 Jul 3 12:25 last_update
drwxrwxrwx 2 systemd-resolve systemd-timesync 1024 Jul 8 11:01 Legimi
drwxr-xr-x 2 root root 1024 Jul 5 16:10 logo
drwxr-xr-x 2 root root 12288 Jan 1 2000 lost+found
-rw-r--r-- 1 root root 343 Jul 10 2016 man2wall.txt
-rw-rw-rw- 1 root root 139 Jul 14 08:01 monitorinfo
-rw-r--r-- 1 root root 25 Jul 14 08:01 netdevcache
-rw-r--r-- 1 root root 195 Jul 8 11:02 network.conf
drwxrwx--- 2 systemd-resolve systemd-timesync 1024 Oct 23 2013 pbpk
drwxrwxrwx 5 root root 1024 Jul 5 18:20 pb_sshd5
drwxr-xr-x 2 1000 1000 1024 Jan 1 2000 ppbk
-rw-rw-rw- 1 root root 8 Oct 3 2015 reg.status
drwxrwxrwx 2 systemd-resolve systemd-timesync 1024 Jul 8 10:56 runonce
-rw-r--r-- 1 root root 11 Jul 8 10:08 .sd_original_serial
-rw-rw-rw- 1 systemd-resolve systemd-timesync 0 Jul 8 11:01 settings_pass.txt
-rwxrwx--- 1 systemd-resolve systemd-timesync 40 Jul 5 16:10 swupdate.db
For replacing the pocketbook link to monitor app, I went into /dev/sdd8, copied the patched version of monitor.app, moved the old link, and made a new one. I have this:
Code:
root@kali:/media/root/disk1# df -k .
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sdd8 249983 200078 37388 85% /media/root/disk1
root@kali:/media/root/disk1# ls -l
total 127246
drwxr-xr-x 2 1028 users 2048 Jul 17 2017 adobefonts
drwxr-xr-x 2 1028 users 1024 Jul 17 2017 applications
drwxr-xr-x 2 1028 users 3072 Jul 17 2017 bin
drwxr-xr-x 4 1028 users 1024 Jul 17 2017 config
drwxr-xr-x 2 1028 users 1024 Jul 17 2017 cramfs
-rw-r--r-- 1 1028 users 116277248 Jul 17 2017 cramfs.img
drwxr-xr-x 10 root root 1024 Jul 5 16:08 demo
drwxr-xr-x 3 1028 users 2048 Jul 17 2017 fonts
-rw-r--r-- 1 1028 users 2623 Jul 17 2017 fsimage.md5
-rw-r--r-- 1 1028 users 287713 Jul 17 2017 fsimage.tar.gz
drwxr-xr-x 4 1028 users 2048 Jul 17 2017 language
drwxr-xr-x 6 1028 users 8192 Jul 17 2017 lib
drwxr-xr-x 2 1028 users 1024 Jul 17 2017 libexec
drwxr-xr-x 2 1028 users 1024 Jul 17 2017 license
drwxr-xr-x 2 1028 users 1024 Jul 17 2017 logo
drwxr-xr-x 2 1028 users 1024 Jul 17 2017 logo2
drwx------ 2 root root 12800000 Jul 17 2017 lost+found
-rwxr--r-- 1 root root 387543 Jul 8 10:06 monitor.1225patched.app
lrwxrwxrwx 1 root root 23 Jul 8 10:06 pocketbook -> monitor.1225patched.app
lrwxrwxrwx 1 1028 users 15 Jul 17 2017 pocketbook.ORG -> bin/monitor.app
drwxr-xr-x 2 1028 users 1024 Jul 17 2017 sbin
drwxr-xr-x 17 1028 users 1024 Jul 17 2017 share
drwxr-xr-x 2 1028 users 1024 Jul 17 2017 themes
4/ Yes, I put the SD card back and everything is working.
To answer your final question, the original SD was 4 Gb, the new one is 16.
My user partition is 13+ Gb, and I have added a /dev/sdd4 ext2 partition to have native linux file system to play with (see fdisk -l output above).
I can't really explain the steps to make /dev/sdd1 bigger, I did not take notes for those steps.
I remember using fdisk to delete the old FAT32 partition and create the bigger one. Because of the strange partition layout I was not able to create it at the exact offset than the original. I am not sure if not respecting the value is important or not, but after creating it, I used a disk editor to patch the offset and restore the deleted partition start offset.
I also used fdisk to create the 1 Gb partition #4 which does not exist in original SD card layout.
I had no fear playing around like that since I have the SD card image to start over in case something wen wrong.
While the SD card was in my PC, I modified /etc/sudoers to allow everything, created a mnt/alt directory and modified /etc/fstab to automatically mount my etx2 partition inside it at system startup.
Code:
root@kali:/media/root/disk# cat etc/fstab
none /proc proc defaults 0 0
none /dev/pts devpts mode=0622 0 0
tmpfs /dev/shm tmpfs defaults 0 0
/dev/mmcblk0p4 /mnt/alt auto defaults 0 0
/dev/mmcblk0p8 /ebrmain auto ro 0 0
/dev/mmcblk0p9 /mnt/secure auto defaults 0 0
/ebrmain/cramfs.img /ebrmain/cramfs auto defaults,loop 0 0
Edit: I could have put the .sd_original_serial file elsewhere, same with patched monitor.app, but this was done in a long process and made things like I felt. One thing you cannot avoid is modifying /dev/sdd8 to replace the link, or create a new cramfs.img and replace it (overkill in my opinion).
Now it is done, but if I had to start over again, I would place those two files in the new #4 partition.
This will not survive a firmware upgrade, but the device is "old" and I do not care.
I hope I have been clear enough and you will be able to extend your partition, I regret not having taken notes of this step.