[PATCH resend 0/3] ARM: KDB FIQ debugger

From: Anton Vorontsov
Date: Sun Jan 06 2013 - 20:27:39 EST

Hello Andrew, Russell,

Just resending this once again...

(Also rebased onto v3.8-rc2, and since there were some irqdomain changes,
I had to drop VIC changes from the series, and place the IRQ rerouting
code into the board code. But that is even better, so far we don't need it
anywhere else.)

Short description of the KDB/FIQ debugger:

The FIQ debugger is a facility that can be used to debug situations when
the kernel stuck in uninterruptable sections, e.g. the kernel infinitely
loops or deadlocked in an interrupt or with interrupts disabled. On some
development boards there is even a special NMI button, which is very
useful for debugging weird kernel hangs.

And FIQ is basically an NMI, it has a higher priority than IRQs, and upon
IRQ exception FIQs are not disabled. It is still possible to disable FIQs
(as well as some "NMIs" on other architectures), but via special means.

Old changelogs and a full rationale for these patches can be found here:

v1-v5, rationale: http://lkml.org/lkml/2012/9/10/2
v6: http://lkml.org/lkml/2012/9/10/2
v7: http://lkml.org/lkml/2012/9/13/367
v8: http://lkml.org/lkml/2012/9/19/525
v9: http://lkml.org/lkml/2012/9/24/538


arch/arm/Kconfig | 19 ++++
arch/arm/include/asm/kgdb.h | 7 ++
arch/arm/kernel/Makefile | 1 +
arch/arm/kernel/entry-armv.S | 167 +---------------------------
arch/arm/kernel/entry-header.S | 170 +++++++++++++++++++++++++++++
arch/arm/kernel/kgdb_fiq.c | 118 ++++++++++++++++++++
arch/arm/kernel/kgdb_fiq_entry.S | 87 +++++++++++++++
arch/arm/mach-versatile/Makefile | 1 +
arch/arm/mach-versatile/kgdb_fiq.c | 55 ++++++++++
9 files changed, 459 insertions(+), 166 deletions(-)
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