fix(bl31): avoid clearing of argument registers in RESET_TO_BL31 case

It was assumed that BL31 is the first bootloader to run so there's
no argument to relay from a previous bootloader in RESET_TO_BL31
case, however this is not true for every platform with a non-TF-A
bootloader that might get executed before BL31 while compiling in
RESET_TO_BL31 feature.

Thus, by avoiding zeroing registers, the arguments passed from the
previous bootloader to BL31 are preserved.

Change-Id: I7bb66a10d1fd551ba3fd59a7a38ab5bde3197f72
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
This commit is contained in:
Manish V Badarkhe 2023-02-21 11:13:34 +00:00
parent 5025546c08
commit 3e14df6f63

View file

@ -66,17 +66,6 @@ func bl31_entrypoint
_init_c_runtime=1 \
_exception_vectors=runtime_exceptions \
_pie_fixup_size=BL31_LIMIT - BL31_BASE
/* ---------------------------------------------------------------------
* For RESET_TO_BL31 systems, BL31 is the first bootloader to run so
* there's no argument to relay from a previous bootloader. Zero the
* arguments passed to the platform layer to reflect that.
* ---------------------------------------------------------------------
*/
mov x20, 0
mov x21, 0
mov x22, 0
mov x23, 0
#endif /* RESET_TO_BL31 */
/* --------------------------------------------------------------------