On Thu, 19 Feb 2026 at 12:27, Igor Mammedov <[email protected]> wrote: > > On Wed, 18 Feb 2026 19:10:02 +0000 > Peter Maydell <[email protected]> wrote: > > The sbsa-ref machine already implements an sbsa-gwdt watchdog... > > yep, but not exposed as WDAT one. Hence the question. > It also would need clock-frequency tweak if we are expose it via ACPI. > > PS: > I don't even see DT mapping for it, > looks like sbsa-gwdt is just wired for the sake of compliance with the spec. > Well sbsa-ref specific firmware could just opencode it's mapping instead > of getting it from QEMU.
The way the sbsa-ref board works is that it's supposed to be a reference system and software stack that behaves like a real hardware system would. So the "dtb" is not a proper DTB, it's just a way to tell the firmware a few key details (that on real hardware it would probably interrogate a BMC to find out). The firmware knows the memory map and what devices are present, and the ACPI tables to pass to the guest are entirely handled by the firmware, in the same way they are on real hardware. QEMU's ACPI-fragment handling mechanisms are not used at all. (This is noted in docs/system/arm/sbsa.rst.) thanks -- PMM
