Apply stricter speculative load restriction
The SCTLR.DSSBS bit is zero by default thus disabling speculative loads.
However, we also explicitly set it to zero for BL2 and TSP images when
each image initialises its context. This is done to ensure that the
image environment is initialised in a safe state, regardless of the
reset value of the bit.
Change-Id: If25a8396641edb640f7f298b8d3309d5cba3cd79
Signed-off-by: John Tsichritzis <john.tsichritzis@arm.com>
diff --git a/bl2/aarch64/bl2_entrypoint.S b/bl2/aarch64/bl2_entrypoint.S
index 611b807..c820cd1 100644
--- a/bl2/aarch64/bl2_entrypoint.S
+++ b/bl2/aarch64/bl2_entrypoint.S
@@ -41,12 +41,14 @@
/* ---------------------------------------------
* Enable the instruction cache, stack pointer
- * and data access alignment checks
+ * and data access alignment checks and disable
+ * speculative loads.
* ---------------------------------------------
*/
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el1
orr x0, x0, x1
+ bic x0, x0, #SCTLR_DSSBS_BIT
msr sctlr_el1, x0
isb