• Differences between Privilege Modes and Non-Privilege Mode ?
    Hi everyone , I'm currently using a Cortex-A9 processor (NXP Freescale i.MX6S). My project is to develop a simple OS, but I met a problem: When I am trying to control some peripherals (such as...
  • Reduce ARM CM0+ scatter initialization during boot?
    We are using ARM CM0+ in our embedded SoC design and I noticed that boot takes a long time. Specifically, I saw that it took ~18K cycles after the unreset before we executed an instruction that I recognize...
  • Cortex-M0+ privileged/unprivileged extensions
    Hi all, According with ARMv6-M architecture reference manual, it supports two operation modes, handler mode and thread mode. - "execution in handler mode is always privileged." - "execution in...
  • Best way run driver code in privilege mode?
    I want to write some drivers that run in privilege mode. For example if I have a UART write function I want to make it easy to wrap the write function such that it runs in privilege mode. My thought was...
  • Cortex-M MPU User access to privileged code
    Hi All, I currently want to make use of the MPU. I have several functions which are required to be in privileged mode and are stored in a region set as privileged-read-only, user denied, executable...