feat(fwu): add platform hook for getting the boot index
Add a platform hook for returning the boot index, i.e. the bank from
which the platform has booted the updatable firmware images. This
value will be passed to the Update Agent.
Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Change-Id: Ic7bef21071c48cfc7b69c50e89df9ff758d95b00
diff --git a/docs/getting_started/porting-guide.rst b/docs/getting_started/porting-guide.rst
index be04b97..7f10ca6 100644
--- a/docs/getting_started/porting-guide.rst
+++ b/docs/getting_started/porting-guide.rst
@@ -932,6 +932,25 @@
Alongside, returns device handle and image specification from the I/O policy
of the requested FWU metadata image.
+Function : plat_fwu_get_boot_idx() [when PSA_FWU_SUPPORT == 1]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ Argument : void
+ Return : uint32_t
+
+This function is mandatory when PSA_FWU_SUPPORT is enabled. It provides the
+means to retrieve the boot index value from the platform. The boot index is the
+bank from which the platform has booted the firmware images.
+
+By default, the platform will read the metadata structure and try to boot from
+the active bank. If the platform fails to boot from the active bank due to
+reasons like an Authentication failure, or on crossing a set number of watchdog
+resets while booting from the active bank, the platform can then switch to boot
+from a different bank. This function then returns the bank that the platform
+should boot its images from.
+
Common optional modifications
-----------------------------