http://valinet6l6tq6d5yohaa6gdsf2ho4qcqcxyj2nahp5kd4z7nsa6ycdqd.onion/2024/07/23/Proper-and-easy-RAM-reservation-for-embedded-devices-running-Linux.html
Well, at this point, still with /dev/mem , so we only solved half of the problem. For the other half, we can employ a safe hack this time: overlay a generic-uio device over it (again, using the device tree), which is a simple driver which just maps memory to user space of a certain size.