Merge pull request #634 from sandrine-bailleux-arm/sb/exception-vectors

Improve robustness and readability of exception code

1 files changed, 27 insertions, 2 deletions

diff --git a/include/common/asm_macros.S b/include/common/asm_macros.S
index a331c051..d4bd11ee 100644
--- a/include/common/asm_macros.S
+++ b/include/common/asm_macros.S
@@ -66,11 +66,36 @@
 	b.ne	$label
 	.endm
 
+	/*
+	 * Declare the exception vector table, enforcing it is aligned on a
+	 * 2KB boundary, as required by the ARMv8 architecture.
+	 * Use zero bytes as the fill value to be stored in the padding bytes
+	 * so that it inserts illegal AArch64 instructions. This increases
+	 * security, robustness and potentially facilitates debugging.
+	 */
+	.macro vector_base  label
+	.section .vectors, "ax"
+	.align 11, 0
+	\label:
+	.endm
+
+	/*
+	 * Create an entry in the exception vector table, enforcing it is
+	 * aligned on a 128-byte boundary, as required by the ARMv8 architecture.
+	 * Use zero bytes as the fill value to be stored in the padding bytes
+	 * so that it inserts illegal AArch64 instructions. This increases
+	 * security, robustness and potentially facilitates debugging.
+	 */
+	.macro vector_entry  label
+	.section .vectors, "ax"
+	.align 7, 0
+	\label:
+	.endm
 
 	/*
-	 * This macro verifies that the a given vector doesn't exceed the
+	 * This macro verifies that the given vector doesn't exceed the
 	 * architectural limit of 32 instructions. This is meant to be placed
-	 * immedately after the last instruction in the vector. It takes the
+	 * immediately after the last instruction in the vector. It takes the
 	 * vector entry as the parameter
 	 */
 	.macro check_vector_size since