How can I map a specific keyboard key to be SysRq?

I am using Parabola GNU/Linux (Arch variant) on a MacBook Pro laptop. I would like to configure/enable the SysRq key, since I am experiencing fairly frequent system freezes, which are forcing me currently to have to hard-reboot the system. I have checked /proc/config.gz and it seems the SysRq key is enabled in the kernel config: CONFIG_MAGIC_SYSRQ=y So, my questions are as follows: a) How can I verify what (if any) key is currently mapped to SysRq? b) I would like to remap the Apple 'Command' key to SysRq (since I don't believe it is currently being used). How can I do that? **Edit:** Referring to the answer given here , the contents of `/proc/sys/kernel/sysrq' is as follows: $ cat /proc/sys/kernel/sysrq 0 this seems to indicate that the SysRq key is disabled (despite apparently being enabled in the kernel config) - why is that? (note that I don't believe that linked answer addresses part a) of my question).