Serial console over KGDB NMI debugger port
modulename: kgdb_nmi.ko
configname: CONFIG_SERIAL_KGDB_NMI
Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>Serial drivers
└─>Serial console over KGDB NMI debugger port
In linux kernel since version 3.1 (release Date: 2011-10-24)
This special driver allows you to temporary use NMI debugger port
as a normal console (assuming that the port is attached to KGDB).
Unlike KDB's disable_nmi command, with this driver you are always
able to go back to the debugger using KGDB escape sequence ($3#33).
This is because this console driver processes the input in NMI
context, and thus is able to intercept the magic sequence.
Note that since the console interprets input and uses polling
communication methods, for things like PPP you still must fully
detach debugger port from the KGDB NMI (i.e. disable_nmi), and
use raw console.
If unsure, say N.
as a normal console (assuming that the port is attached to KGDB).
Unlike KDB's disable_nmi command, with this driver you are always
able to go back to the debugger using KGDB escape sequence ($3#33).
This is because this console driver processes the input in NMI
context, and thus is able to intercept the magic sequence.
Note that since the console interprets input and uses polling
communication methods, for things like PPP you still must fully
detach debugger port from the KGDB NMI (i.e. disable_nmi), and
use raw console.
If unsure, say N.