docs: document do_panic() and panic() helper functions
panic() and do_panic() are widely used helper functions called when
encountering a critical failure that cannot be recovered from.
Document them in porting guide. Also, remove panic() documentation
from PSCI guide(where it is unused anyways).
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: Ib0965cce56c03d0de5ac0d05d5714a6942793ede
diff --git a/docs/getting_started/porting-guide.rst b/docs/getting_started/porting-guide.rst
index 6996c17..210fb68 100644
--- a/docs/getting_started/porting-guide.rst
+++ b/docs/getting_started/porting-guide.rst
@@ -3156,6 +3156,34 @@
(``GICD_IGRPMODRn``) is read to figure out whether the interrupt is configured
as Group 0 secure interrupt, Group 1 secure interrupt or Group 1 NS interrupt.
+Common helper functions
+-----------------------
+
+Function : do_panic()
+~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ Argument : void
+ Return : void
+
+This API is called from assembly files when encountering a critical failure that
+cannot be recovered from. It also invokes elx_panic() which allows to report a
+crash from lower exception level. This function assumes that it is invoked from
+a C runtime environment i.e. valid stack exists. This call **must not** return.
+
+Function : panic()
+~~~~~~~~~~~~~~~~~~
+
+::
+
+ Argument : void
+ Return : void
+
+This API called from C files when encountering a critical failure that cannot
+be recovered from. This function in turn prints backtrace (if enabled) and calls
+do_panic(). This call **must not** return.
+
Crash Reporting mechanism (in BL31)
-----------------------------------