Add dual-core Cortex-A examples #188
Description
The AMD Zynq 7000:
- is emulated by QEMU
- is popular with users of this crate
- has two Cortex-A9 cores, so can test SMP support on Cortex-A (we only test dual-core Cortex-R52 currently)
- has a PMSAv7 MMU, so we can test that code too
So a simple Zynq 7000 example in this tree might be useful.
Activity
sriramster commentedon Jul 1, 2026
Hello @jonathanpallant I wanted to take this issue up. But I've a few questions would you help?
Thank you.
jonathanpallant commentedon Jul 2, 2026
sriramster commentedon Jul 2, 2026
Yes, for (2) Adding/Extending the generic_timer module from the trait would suffice. And the invocation could be cfg-gated. I'll wait for (1). From @robamu . Thank you.
robamu commentedon Jul 2, 2026
I have a low level PAC API which is part of the zynq7000 crate and a more high level driver in zynq7000-hal. Those might help.
GIC PAC: https://github.com/us-irs/zynq7000-rs/blob/main/firmware%2Fzynq7000%2Fsrc%2Fgic.rs
GIC HAL: https://github.com/us-irs/zynq7000-rs/blob/main/firmware%2Fzynq7000-hal%2Fsrc%2Fgic.rs
robamu commentedon Jul 3, 2026
I was planning a new HAL release.. but another option would also be to copy and paste relevant stuff and API, or combine the approached and only use the PAC, write a very basic HAL driver for the example.
sriramster commentedon Jul 3, 2026
@robamu Do you recommend having just the driver code within the examples? (In this case for the specific example)
thejpster commentedon Jul 12, 2026
I try and keep the examples as light-weight as possible - they are supposed to be educational rather than production-ready. So I would include the bare minimum required to show that both processor cores are running and can ping each other. This probably requires a GIC driver, but a WFE/SEV ping pong would also work.
thejpster commentedon Jul 12, 2026
See #205 where I brought SMP support into the library, hopefully making SMP examples much easier to write. Now you just need a secondary core park function of some kind.
sriramster commentedon Jul 26, 2026
@thejpster I think this can be closed now?
thejpster commentedon Jul 26, 2026
@jonathanpallant close this when you get to a PC