ARMv7 may not support Virtualization Extensions
ARMv7-A Virtualization extensions brings new instructions and resources
that were supported by later architectures. Reference ARM ARM Issue C.c
[DDI0406C_C].
ERET and extended MSR/MRS instructions, as specified in [DDI0406C_C] in
ID_PFR1 description of bits[15:12] (Virtualization Extensions):
A value of 0b0001 implies implementation of the HVC, ERET, MRS
(Banked register), and MSR (Banked register) instructions. The ID_ISARs
do not identify whether these instructions are implemented.
UDIV/SDIV were introduced with the Virtualization extensions, even if
not strictly related to the virtualization extensions.
If ARMv7 based platform does not set ARM_CORTEX_Ax=yes, platform
shall define ARMV7_SUPPORTS_VIRTUALIZATION to enable virtualization
extension related resources.
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
diff --git a/include/common/aarch32/asm_macros.S b/include/common/aarch32/asm_macros.S
index 0d1a37d..7432222 100644
--- a/include/common/aarch32/asm_macros.S
+++ b/include/common/aarch32/asm_macros.S
@@ -79,6 +79,16 @@
ldr r0, =(\_name + \_size)
.endm
+#if ARM_ARCH_MAJOR == 7 && !defined(ARMV7_SUPPORTS_VIRTUALIZATION)
+ /*
+ * ARMv7 cores without Virtualization extension do not support the
+ * eret instruction.
+ */
+ .macro eret
+ movs pc, lr
+ .endm
+#endif
+
#if (ARM_ARCH_MAJOR == 7)
/* ARMv7 does not support stl instruction */
.macro stl _reg, _write_lock