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AR# 63208

Zynq - Linux - Zynq Peripheral Unavailable from One CPU When Linux Boots on the Other CPU.


I am booting my Zynq system in an AMP configuration where Linux boots on one CPU and a different operating system boots on the other ARM CPU. 

In this configuration, once Linux boots, a peripheral that should be accessible from the second CPU is no longer accessible.


This behavior is due to a feature in the Linux kernel where it disables the clocks for unused peripherals.

This can cause peripherals to be inaccessible from the other CPU because the clock for the peripheral has been disabled by the Linux kernel.

To work around this behavior, pass the boot argument "clk_ignore_unused" to the Linux kernel.
AR# 63208
Date Created 12/19/2014
Last Updated 03/04/2015
Status Active
Type General Article
  • SoC
  • Zynq-7000