Almost all PA-RISC machines have either a button that is labeled with 'TOC' or
a BMC/GSP function to trigger a TOC. TOC is a non-maskable interrupt that is
sent to the processor. This can be used for diagnostic purposes like obtaining
a stack trace/register dump or to enter KDB/KGDB in Linux.
This patch adds support for such an emulated TOC button.
It wires up the qemu monitor "nmi" command to trigger a TOC. For that it
provides the hppa_nmi function which is assigned to the nmi_monitor_handler
function pointer. When called it raises the EXCP_TOC hardware interrupt in the
hppa_cpu_do_interrupt() function. The interrupt function then calls the
architecturally defined TOC function in SeaBIOS-hppa firmware (at fixed address
0xf0000000).
According to the PA-RISC PDC specification, the SeaBIOS firmware then writes
the CPU registers into PIM (processor internal memmory) for later analysis. In
order to write all registers it needs to know the contents of the CPU "shadow
registers" and the IASQ- and IAOQ-back values. The IAOQ/IASQ values are
provided by qemu in shadow registers when entering the SeaBIOS TOC function.
This patch adds a new aritificial opcode "getshadowregs" (0xfffdead2) which
restores the original values of the shadow registers. With this opcode SeaBIOS
can store those registers as well into PIM before calling an OS-provided TOC
handler.
To trigger a TOC, switch to the qemu monitor with Ctrl-A C, and type in the
command "nmi". After the TOC started the OS-debugger, exit the qemu monitor
with Ctrl-A C.
Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.
Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Message-Id: <20201023123353.19796-1-chetan4windows@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The current qemu hppa emulation emulates a PA1.1 CPU, which can only execute
the 32-bit instruction set. For unknown 64-bit instructions, a instruction trap
is sent to the virtual CPU.
This behaviour is correct in the sense that we emulate what the PA1.1
specification says.
But when trying to boot older Linux installation images, e.g.
ftp://parisc.parisc-linux.org/debian-cd/debian-5.0/lenny-5.0.10-hppa-iso-cd/cdimage.debian.org/debian-5010-hppa-netinst.iso
one finds that qemu fails to boot those images.
The problem is, that in the Linux kernel (e.g. 2.6.26) of those old images
64-bit instructions were used by mistake in the fault handlers. The relevant
instructions (the ",*" indicates that it's a 64-bit instruction) I see are:
0: 09 3e 04 29 sub,* sp,r9,r9
0: 08 3d 06 3d add,* ret1,r1,ret1
0: 0a 09 02 61 or,* r9,r16,r1
0: 0a ba 00 3a andcm,* r26,r21,r26
0: 08 33 02 33 and,* r19,r1,r19
The interesting part is, that real physical 32-bit machines (like the 700/64
and B160L - which is the one we emulate) do boot those images and thus seem to
simply ignore the 64-bit flag on those instructions.
The patch below modifies the qemu instruction decoder to ignore the 64-bit flag
too - which is what real 32-bit hardware seems to do. With this modification
qemu now successfully boots those older images too.
I suggest to apply the patch below - even if it does not reflect what the SPEC
says. Instead it increases the compatibility to really existing hardware and
seem to not create problems if we add real PA2.0 support anytime later.
Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
These instructions are present on pcxl and pcxl2 machines,
and are used by NetBSD and OpenBSD. See
https://parisc.wiki.kernel.org/images-parisc/a/a9/Pcxl2_ers.pdf
page 13-9 (195/206)
Signed-off-by: Nick Hudson <skrll@netbsd.org>
Message-Id: <20190423063621.8203-2-nick.hudson@gmx.co.uk>
[rth: Use extending loads, locally managed temporaries.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
DIAG is usually only used by diagnostics software as it's CPU
specific. In most of the cases it's better to ignore it and log
a message that it's not implemented.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Message-Id: <20190311191602.25796-7-svens@stackframe.org>
[rth: Free the nullify condition.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Convert the BREAK instruction to start.
Tested-by: Helge Deller <deller@gmx.de>
Tested-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
