On Wed, 7 May 2014, Alexander Graf wrote:
On 05/07/2014 05:31 PM, Tom Musta wrote:
On 5/6/2014 6:17 PM, BALATON Zoltan wrote:
On Tue, 6 May 2014, Tom Musta wrote:
(2) Your patch makes some store instructions compliant with the
most recent ISAs but there are many other instructions that are
not addressed by the patch. I think fixing only some will be a
future source of confusion.>>
Alex: do you have an opinion on this? Are you OK with changing
masks for a few stores but not all instructions in general?
I would like to see someone just test all those load/store
instructions on old CPUs and see whether they fault. If none faults,
we should just be consistent and remove them for all. If say a 750
really only ignores the Rc bit for stwx for some reason we should
just model it accordingly.
To get some answers to this and other questions that are still open
I've made a test program by stripping down yaboot and adding tests to
it so that it should be possible to run from Open Firmware as a boot
loader. It can be found here:
http://goliat.eik.bme.hu/~balaton/oftest/
The files there are:
* oftest - an ELF executable that you can put on some device OF can read
and run it if it were a boot loader ( e.g. 0> boot
hd0,0:\oftest )
* oftest.hfs.xz - the same file on an 800k HFS volume that can be put on
e.g. a USB drive or CD then used as the previous one
* oftest-src.tar.xz - the source
When run from Open Firmware it should print some information about
memory layout, MSR setting, stack location, BAT registers and test
the stwx opcode with and without reserved bit which should help us
understand better the differences between QEMU and real hardware. I
could only test it on QEMU though.