Messages in this thread | | | From | Andy Shevchenko <> | Date | Tue, 10 Dec 2019 19:00:07 +0200 | Subject | Re: [PATCH v2 10/11] gpiolib: add new ioctl() for monitoring changes in line info |
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On Fri, Dec 6, 2019 at 11:20 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote: > czw., 5 gru 2019 o 18:02 Andy Shevchenko <andy.shevchenko@gmail.com> napisał(a): > > On Thu, Dec 5, 2019 at 3:47 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote: > > > czw., 5 gru 2019 o 11:27 Andy Shevchenko <andy.shevchenko@gmail.com> napisał(a): > > > > On Thu, Dec 5, 2019 at 11:42 AM Bartosz Golaszewski > > > > <bgolaszewski@baylibre.com> wrote: > > > > > śr., 4 gru 2019 o 23:34 Andy Shevchenko <andy.shevchenko@gmail.com> napisał(a): > > > > > > On Wed, Dec 4, 2019 at 6:03 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote: > > > > > > So, the test cases, I can imagine of, should include (k - kernel, u - user): > > > > - 64k-64u: LE and BE > > > > - 64k-32u: LE and BE > > > > - 32k-32u: LE and BE > > > > > > I usually use qemu VMs built with yocto for testing but I don't see > > > any way of creating a 32-bit user-space with 64-bit kernel. Any ideas > > > on how to prepare a testing environment? > > > > In my case it's very easy. I do > > - compile kernel as 64-bit separately; > > - compile initramfs of Buildroot distro with external kernel build provided. > > > > Any specific config options are needed on x86-64 kernel to use 32-bit > user-space? I'm not well versed in x86 architectures, that's why I'm > asking. I built a 32-bit userspace qemu image with yocto and then > manually built a 64-bit kernel. I tried running it but I'm getting a > kernel panic when the rootfs is being mounted.
Just published set of scripts [1] we are using internally for our development. Find README.coreteam in the source root and read how to use that.
> On a different note: why would endianness be an issue here? 32-bit > variables with 64-bit alignment should still be in the same place in > memory, right?
With explicit padding, yes.
> Any reason not to use __packed for this structure and not deal with > this whole compat mess?
Have been suggested that explicit padding is better approach. (See my answer to Kent)
> I also noticed that my change will only allow user-space to read one > event at a time which seems to be a regression with regard to the > current implementation. I probably need to address this too.
Yes, but we have to have ABI v2 in place.
[1]: https://github.com/andy-shev/buildroot/tree/intel
-- With Best Regards, Andy Shevchenko
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