This implements support for NMI debugging that was shamelessly copied
from the avr32 port. A bit of special magic is needed in the interrupt
exception path given that the NMI exception handler is stubbed in to the
regular exception handling table despite being reported in INTEVT. So we
mangle the lookup and kick off an EXPEVT-style exception dispatch from
the INTEVT path for exceptions that do_IRQ() has no chance of handling.
As a result, we also drop the evt2irq() conversion from the do_IRQ() path
and just do it in assembly.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This migrates from the old bitrotted kgdb stub implementation and moves
to the generic stub. In the process support for SH-2/SH-2A is also added,
which the old stub never provided.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Signed-off-by: NKieran Bingham <kbingham@mpc-data.co.uk>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This was all reworked some time ago, the old debug_enter was ripped
out with everything going through a debug trap jump table instead.
Kill off the debug_enter target and reference kgdb_handle_exception
directly.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The only difference between these at the moment are the FPU
exceptions, and these are hidden away under CONFIG_SH_FPU
(which is only set for the SH-4 case anyways..).

This consolidates the two tables, and updates SH-4 to use
the updated copy.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

With the recent change ripping out interrupt_table, explicit
padding of the table was missing, causing bad things to happen
when manually inserting handlers in to the table. This problem
particularly showed up in relation to do_fpu_state_restore()
which was inserted quite deeply in to the table and ended up
scribbling over a slab object.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Kill off interrupt_table for all of the CPU subtypes, we now
default in to stepping in to do_IRQ() for _all_ IRQ exceptions
and counting the spurious ones, rather than simply flipping on
the ones we cared about. This and enabling the IRQ by default
automatically has already uncovered a couple of bugs and IRQs
that weren't being caught, as well as some that are being
generated far too often (SCI Tx Data Empty, for example).

The general rationale is to use a marker for interrupt exceptions,
test for it in the handle_exception() path, and skip out to
do_IRQ() if it's found. Everything else follows the same behaviour
of finding the cached EXPEVT value in r2/r2_bank, we just rip out
the INTEVT read from entry.S entirely (except for in the kGDB NMI
case, which is another matter).

Note that while this changes the do_IRQ() semantics regarding r4
handling, they were fundamentally broken anyways (relying entirely
on r2_bank for the cached code). With this, we do the INTEVT read
from do_IRQ() itself (in the CONFIG_CPU_HAS_INTEVT case), or fall
back on r4 for the muxed IRQ number, which should also be closer
to what SH-2 and SH-2A want anyways.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This adds support for the aforementioned CPU subtypes, and cleans
up some build issues encountered as a result.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!