15 ms·
> It seems to me that an MMU is no good if the board doesn't have enough RAM to run a general-purpose operating system, as opposed to a bare-metal program or a
by wolfgke 10y ago
> It seems to me that an MMU is no good if the board doesn't have enough RAM to run a general-purpose operating system, as opposed to a bare-metal program or a real-time OS like a microcontroller usually uses.
For a realtime operating system at least a Memory Protection Unit (to use the word that ARM introduced for this limited form of an MMU) is very useful since it can easily make the OS much more reliable if a process cannot write to memory adresses of the kernel or other processes.
EDIT: Or is such an MPU implied by the support for "Privileged ISA Specification v1.9.1"?
- pjmlp 10y ago> is very useful since it can easily make the OS much more reliable if a process cannot write to memory adresses of the kernel or other processes. If you make use of memory safe systems programming languages on bare metal, like Ada, SPARK, Rust, Oberon-07 than it isn't usually an issue, since the unsafe code will be quite constrained. For example, http://www.astrobe.com/boards.htm http://www.astrobe.com/boards.htm