After doing some more experiments with eMMC cloning (basically, dd'ing the entire phone's flash contents to a different phone), I've discovered that this will break cell functionality by disrupting some of the phone's identity information.
This kind of sucks, because if download mode runs, this is all that's required for full access to the entire internal storage, and it's possible to restore the phone even if the LG tool craps out on it. However, unless you've made a full backup of your internal storage, you'll never get the cell network to function after restoring. I have not tried running LG flash tool on a phone that's been restored with this method. Maybe it will fix it. Maybe not.
I don't know what parts of the internal storage store this identity info, but if they were identified, it would be possible to pull just those areas out of a badly mangled eMMC and insert them into a recovery image.
For those curious, this is the method I use to read and write the entire raw flash:
Use linux and this python script: https://gist.github.com/corwin-of-amber/8f5ce36611dce12950e8d34a608f5ece
The mechanism this script uses to get a shell isn't very reliable. You will find that sometimes commands don't execute. Sometimes commands execute but don't send back a reply. Long replies don't work properly either. Be aware of this. Try the command again if needed. Troubleshoot with something simple like the ls command. Warning: This shell does not implement anything more than just running a command with arguments. No tab completion, no redirection (< or >), and probably no way to ctrl+c a command executing.
Sometimes you have to quit the python script and run it again, or run it on a 2nd USB serial that shows up. You may need to use the ENTER or LEAVE commands to get it in a state suitable for this.
Have a fat32 formatted SD card of at least 8GB in the phone. Put a busybox binary on it. When you enter download mode, the SD card will automatically mount.
Unmount all of the phone partitions that you can (use "mount" command to view, then umount them - system probably won't unmount but it's mounted read-only so it shouldn't get in the way)
You can use the busybox binary's dd applet to move stuff between the emmc and SD card, but note that fat32 has a 4GB file limit. You need to split a full image into at least 2 parts to fit it in the SD.
If anyone is looking at trying this stuff and wants some advice, PM me.
This kind of sucks, because if download mode runs, this is all that's required for full access to the entire internal storage, and it's possible to restore the phone even if the LG tool craps out on it. However, unless you've made a full backup of your internal storage, you'll never get the cell network to function after restoring. I have not tried running LG flash tool on a phone that's been restored with this method. Maybe it will fix it. Maybe not.
I don't know what parts of the internal storage store this identity info, but if they were identified, it would be possible to pull just those areas out of a badly mangled eMMC and insert them into a recovery image.
For those curious, this is the method I use to read and write the entire raw flash:
Use linux and this python script: https://gist.github.com/corwin-of-amber/8f5ce36611dce12950e8d34a608f5ece
The mechanism this script uses to get a shell isn't very reliable. You will find that sometimes commands don't execute. Sometimes commands execute but don't send back a reply. Long replies don't work properly either. Be aware of this. Try the command again if needed. Troubleshoot with something simple like the ls command. Warning: This shell does not implement anything more than just running a command with arguments. No tab completion, no redirection (< or >), and probably no way to ctrl+c a command executing.
Sometimes you have to quit the python script and run it again, or run it on a 2nd USB serial that shows up. You may need to use the ENTER or LEAVE commands to get it in a state suitable for this.
Have a fat32 formatted SD card of at least 8GB in the phone. Put a busybox binary on it. When you enter download mode, the SD card will automatically mount.
Unmount all of the phone partitions that you can (use "mount" command to view, then umount them - system probably won't unmount but it's mounted read-only so it shouldn't get in the way)
You can use the busybox binary's dd applet to move stuff between the emmc and SD card, but note that fat32 has a 4GB file limit. You need to split a full image into at least 2 parts to fit it in the SD.
If anyone is looking at trying this stuff and wants some advice, PM me.
