I am running jailbroken iOS 13.5 on an iPad Pro 4. I would love to be able to flash firmware images onto attached USB disks with something like sudo dd bs=1M if=/path/to/ubuntu.iso of=/dev/disk4 however this results in dd: failed to open '/dev/disk4': Operation not permitted. I imagine this is because dd lacks some private entitlement, but I cannot find this information documented anywhere.
What do I need to do to be able to dd into raw disks on jailbroken iOS?
You want com.apple.private.security.disk-device-access:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>com.apple.private.security.disk-device-access</key>
<true/>
</dict>
</plist>