commit 7df15a083f67052a7bc1c8e6ef1483aaa29dcb36
author Eunchan Kim <eunchan@opentitan.org> Thu May 19 13:54:41 2022 -0700
committer Eli Kim <github@elikim.dev> Thu May 19 17:08:54 2022 -0700
tree 1e460c6c1d521d9bf9b4243cf88b69240d256367
parent 53080e4a3dff6a8677e142a3a8223d1c5c1da76c

fix(ottf): Fix incorrect computation of MEPC

Problem:

    In synchronous ISR, the Ibex returned to incorrect PC and caused
    Illegal Instruction fault.

Signed-off-by: Eunchan Kim <eunchan@opentitan.org>

sw/device/lib/testing/test_framework/ottf_isrs.S

diff --git a/sw/device/lib/testing/test_framework/ottf_isrs.S b/sw/device/lib/testing/test_framework/ottf_isrs.S
index 577b684..64e82f0 100644
--- a/sw/device/lib/testing/test_framework/ottf_isrs.S
+++ b/sw/device/lib/testing/test_framework/ottf_isrs.S
@@ -24,9 +24,10 @@
   .type compute_mepc_on_synchronous_irq, @function
 compute_mepc_on_synchronous_irq:
   csrr t0, mepc
+  lh t2, 0(t0)
   li t1, 0x3
-  and t2, t0, t1
-  beq t2, t1, .L_32bit_trap_instr
+  and t3, t2, t1
+  beq t3, t1, .L_32bit_trap_instr
   addi t0, t0, OTTF_HALF_WORD_SIZE
   ret
 .L_32bit_trap_instr: