TF-A: Add support for ARMv8.3-PAuth in BL1 SMC calls and BL2U
This patch adds support for ARMv8.3-PAuth in BL1 SMC calls and
BL2U image for firmware updates by programming APIAKey_EL1 registers
and enabling Pointer Authentication in EL3 and EL1 respectively.
Change-Id: I875d952aba8242caf74fb5f4f2d2af6f0c768c08
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
diff --git a/lib/extensions/pauth/pauth_helpers.S b/lib/extensions/pauth/pauth_helpers.S
index c6808de..d483c7df 100644
--- a/lib/extensions/pauth/pauth_helpers.S
+++ b/lib/extensions/pauth/pauth_helpers.S
@@ -13,6 +13,7 @@
.global pauth_init_enable_el3
.global pauth_disable_el3
.globl pauth_load_bl31_apiakey
+ .globl pauth_load_bl1_apiakey_enable
/* -------------------------------------------------------------
* Program APIAKey_EL1 and enable pointer authentication in EL1
@@ -97,9 +98,9 @@
endfunc pauth_disable_el3
/* -------------------------------------------------------------
- * The following function strictly follows the AArch64 PCS
+ * The following functions strictly follow the AArch64 PCS
* to use x9-x17 (temporary caller-saved registers) to load
- * the APIAKey_EL1 used by the firmware.
+ * the APIAKey_EL1 and enable pointer authentication.
* -------------------------------------------------------------
*/
func pauth_load_bl31_apiakey
@@ -115,3 +116,26 @@
isb
ret
endfunc pauth_load_bl31_apiakey
+
+func pauth_load_bl1_apiakey_enable
+ /* Load instruction key A used by the Trusted Firmware */
+ adrp x9, bl1_apiakey
+ add x9, x9, :lo12:bl1_apiakey
+ ldp x10, x11, [x9]
+
+ /* Program instruction key A */
+ msr APIAKeyLo_EL1, x10
+ msr APIAKeyHi_EL1, x11
+
+ /* Enable pointer authentication */
+ mrs x9, sctlr_el3
+ orr x9, x9, #SCTLR_EnIA_BIT
+
+#if ENABLE_BTI
+ /* Enable PAC branch type compatibility */
+ bic x9, x9, #SCTLR_BT_BIT
+#endif
+ msr sctlr_el3, x9
+ isb
+ ret
+endfunc pauth_load_bl1_apiakey_enable