Hi,
On 1/13/25 12:01 PM, Stafford Horne wrote:
On Mon, Jan 13, 2025 at 11:42:08AM +0530, Sahil Siddiq wrote:
Hi,
Thank you for your reply.
On 1/12/25 12:58 PM, Stafford Horne wrote:
Hi Sunil,
+CC List
yes, the cacheinfo task is still open. There are many things that are still not
implemented in OpenRISC, you can always just look under the kernel
Documentation/features.
For example:
< shorne@antec ~/work/linux > grep -r -e openrisc.*TODO
Documentation/features | column -t
Documentation/features/vm/huge-vmap/arch-support.txt: |
openrisc: | TODO |
Documentation/features/vm/ELF-ASLR/arch-support.txt: |
openrisc: | TODO |
Documentation/features/vm/ioremap_prot/arch-support.txt: |
openrisc: | TODO |
Documentation/features/vm/pte_special/arch-support.txt: |
openrisc: | TODO |
Documentation/features/perf/kprobes-event/arch-support.txt: |
openrisc: | TODO |
...
Got it. I did find this list in the online documentation [1] but I couldn't find
the cacheinfo task listed there.
Right, not all features have config flags that are documented.
Understood. Do you know how one finds these flags? I wasn't able
to find much related to cpu or caches in arch/openrisc/Kconfig [1].
I did find the usage of ARCH_HAS_CPU_CACHE_ALIASING in
include/linux/cacheinfo.h [2]. I am not sure if this is relevant.
How far have you come with OpenRISC so far? If you haven't already I suggest
working through:
- Get a simulator, I use QEMU for most development as it's faster and
supports
more memory than most FPGA. Final verification can be done on an FPGA.
- Get a working compiler toolchain.
- Compile and boot the openrisc kernel.
- Build a userspace environment, either buildroot, toybox or busybox.
I have some tools to help with this in or1k-utils [1], also there are prebuilt
environments and docs in the linux kernel [2] and qemu [3].
I don't have an environment set up yet. I'll start with the steps above. I'll
use
QEMU for development. I don't have an FPGA with me currently.
I have set up a fairly basic environment. I built both QEMU and
openrisc-linux from the master branch. I used a prebuilt compiler
toolchain to build openrisc-linux and busybox, and manually
created an initramfs image. I used the default configuration
options to build linux.
The userspace environment only has utilities that are provided
by busybox. Only the following filesystems have been mounted -
rootfs, devtmpfs, sys, proc and tmpfs.
I tried to understand the workings of some of the scripts in
or1k-utils. There were a few things that I didn't understand
and I'll need some more time to wrap my head around them. I
don't think this should hinder the cacheinfo task though.
Is there anything else that I'll need to set up in the environment
before progressing?
I don't see any cache-related info in /sys. Based on what I have
understood, it'll be possible to fetch these details once cacheinfo
is supported.
At the momoment, I am also thinking of what to work on next for OpenRISC, there
is:
- kexec
- jump_label
- kprobes
- perf_events
- ftrace
Is the virtio task [2] also still a part of the roadmap? I can't find that
either
in the TODO list.
The virtio task is still possible but will be more advanced and may need some
architecture changes to support hypervisors.
Got it.
Thanks,
Sahil
[1] https://github.com/torvalds/linux/blob/master/arch/openrisc/Kconfig
[2] https://github.com/torvalds/linux/blob/master/include/linux/cacheinfo.h#L156
