Rooting smartphones and access to FS?

Question

linux

(For starters, I just want to figure it out)
Let's take smartphones running iOS or Android. The system is *nix-like. Users work with software, which in turn runs in a sandbox. With the software and the system, I understand how protection is implemented.
From a hardware standpoint, no. I am currently developing on / under ARM9 / linux and draw an analogy of protecting smartphones and ARM9-based boards.
Firmware linux in NAND. If desired, on “my” ARM9 board, I can read the contents of the file system by “connecting” NAND to the system and booting from another source. Is it the same with smartphones?
Or is there a special NAND? Or are the partitions encrypted? But is the original bootloader available? He decrypts the section, then the b / m algorithm should be clear. It is clear that they do not go this way when rooting smartphones, tk. it will not be repeated by a regular user.
Or is it somehow more difficult to protect the firmware from accessing the file system?
(Preferably thoughts supported by evidence links)

Answer 1

iOS has a bootrom, it's on the chip, and it's not accessible. Bootloaders (bootrom -> LLB -> iBoot) decrypt the next level and verify the signature. Keys are only known through exploits. Read here: bootchain , iOS security , hacker's handbook .