Re: [PATCH v3 1/8] dt-bindings: arm: Add Live Firmware Activation
From: Andre Przywara
Date: Fri Sep 18 2026 - 04:36:03 EST
Hi,
sorry, just figured that I never replied to this - was stuck in my Draft folder ...
On 7/17/26 10:38, Sudeep Holla wrote:
On Mon, Jul 06, 2026 at 03:44:41PM +0200, Andre Przywara wrote:
The Arm Live Firmware Activation spec [1] describes updating firmware
images during runtime, without requiring a reboot. Update images might
be deployed out-of-band, for instance via a BMC, in this case the OS
needs to be notified about the availability of a new image.
Describe an interrupt that could be triggered by the platform, to notify
about any changes.
[1] https://developer.arm.com/documentation/den0147/latest/
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
.../devicetree/bindings/arm/arm,lfa.yaml | 45 +++++++++++++++++++
1 file changed, 45 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/arm,lfa.yaml
diff --git a/Documentation/devicetree/bindings/arm/arm,lfa.yaml b/Documentation/devicetree/bindings/arm/arm,lfa.yaml
new file mode 100644
index 000000000000..ef8e250f2da7
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/arm,lfa.yaml
@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/arm,lfa.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Arm Live Firmware Activation (LFA)
+
+maintainers:
+ - Andre Przywara <andre.przywara@xxxxxxx>
+ - Sudeep Holla <sudeep.holla@xxxxxxx>
+
+description:
+ The Arm Live Firmware Activation (LFA) specification [1] describes a
+ firmware interface to activate an updated firmware at runtime, without
+ requiring a reboot. Updates might be supplied out-of-band, for instance
+ via a BMC, in which case the platform needs to notify an OS about pending
+ image updates.
What does the below described "interrupts" cover or doesn't cover? Both
in case of in-band and out-of-band. It is not very clear for me.
DEN0147 says (at the very end of the document):
"As of this version of the specification, the expected scope would be notification to the Operating System to indicate new LFA updates are available."
In-band updates are work in progress, spec-wise, and we would cover this when it has arrived. So for now this if for out-of-band updates, so that a BMC for instance can signal the arrival of an updated image to the OS.
I clarified the wording in the description of the interrupt property. I also added that it must be an edge triggered IRQ, as there is no easy way to signal completion, and the ACPI notification has the same semantics.
Cheers,
Andre.