On Mon, 2025-08-18 at 09:48 +0200, Thomas Huth wrote: > On 15/08/2025 00.37, Glenn Miles wrote: > ... > > I have some code that tests the instructions that are > > specific to the PPE42. It is a very basic test written > > in assembly. This can be found at: > > > > https://github.com/milesg-github/ppe42-tests > > > > There is also a prebuilt image there in the images > > folder. > > > > Building the image requires a forked version of an old > > version of GCC, which can be found here: > > > > https://github.com/open-power/ppe42-gcc > > > > Even though everything that is necessary to build the > > image is publicly available, it is not a simple task. > > This is why I think it would be best to just use the > > prebuilt image available on github instead of trying to > > build it. > > With the compiler being not available in the major distros, the idea with > the prebuilt image is better indeed. > > > Also, there is currently no support for having console > > output (this is also not supported in the actual HW). > > All logging on actual hardware is done using in-memory > > trace buffers that requires a special tool for translation > > to a human readable format. Because of this, I'm thinking > > this is not a good candidate for using the QEMU > > "tests/functional" framework, which seems to rely a lot > > on console output. > > > > I do think it would be possible to use the qtest framework > > to load the image and run it. > > > > The existing test will cause a checkstop if it fails. > > This leads to dumping the cpu registers, which aids in > > debug. There is currently no way to tell that the > > test completed, other than checking the NIP address, > > but this could be easily remedied by having the guest > > code write some status to a fixed memory address and > > then having the qtest code poll that memory address > > to determine that the test completed within some reasonable > > timeout period. > > > > The one thing that I'm not sure about with using the > > qtest framework is how to retrieve the image. If anyone > > has suggestions or examples of that being done for a qtest, > > please do share! > > The qtest framework does not have any support for downloading images. I > think you're way better off using the functional framework for this. The > console output is just optional there, so if your image does not have any > serial console output, there are still other means of checking for success. > > For example, if you can be sure that a successful test always ends up with a > certain NIP, you could use > > output = vm.cmd('human-monitor-command', command_line='info registers') > > to check the current status of the registers and check the NIP there. > > And assuming that a checkstop will cause a QMP event, you could likely also > use one of the event functions from python/qemu/machine/machine.py to check > for a failure while waiting for the right NIP. > > HTH, > Thomas >
Thanks for the tip, Thomas! I will give that a try. Glenn
