Test access exception behavior for illegal addresses (#111)

OK'd by @palmer-dabbelt

diff --git a/isa/rv64mi/Makefrag b/isa/rv64mi/Makefrag
index fb38e5f23293d9cfd19e39fc23eed6f2e55e2892..c81c24ebcfd5f8b2d388eba60adc48099bc5f85b 100644 (file)
--- a/isa/rv64mi/Makefrag
+++ b/isa/rv64mi/Makefrag
@@ -3,6 +3,7 @@
 #-----------------------------------------------------------------------
 
 rv64mi_sc_tests = \
+       access \
        breakpoint \
        csr \
        mcsr \

diff --git a/isa/rv64mi/access.S b/isa/rv64mi/access.S
new file mode 100644 (file)
index 0000000..202a364
--- /dev/null
+++ b/isa/rv64mi/access.S
@@ -0,0 +1,70 @@
+# See LICENSE for license details.
+
+#*****************************************************************************
+# access.S
+#-----------------------------------------------------------------------------
+#
+# Test access-exception behavior.
+#
+
+#include "riscv_test.h"
+#include "test_macros.h"
+
+RVTEST_RV64M
+RVTEST_CODE_BEGIN
+
+  .align 2
+
+  # Flipping just the MSB should result in an illegal address for RV64.
+  la t2, fail
+  li t0, 1 << (__riscv_xlen - 1)
+  xor t0, t0, t2
+
+  # jalr to an illegal address should commit (hence should write rd).
+  # after the pc is set to rs1, an access exception should be raised.
+  li TESTNUM, 2
+  li t1, CAUSE_FETCH_ACCESS
+  la t3, 1f
+  li t2, 0
+  jalr t2, t0
+1:
+
+  # A load to an illegal address should not commit.
+  li TESTNUM, 3
+  li t1, CAUSE_LOAD_ACCESS
+  la t3, 1f
+  mv t2, t3
+  lb t2, (t0)
+  j fail
+1:
+
+  j pass
+
+  TEST_PASSFAIL
+
+  .align 2
+  .global mtvec_handler
+mtvec_handler:
+  li a0, 2
+  beq TESTNUM, a0, 2f
+  li a0, 3
+  beq TESTNUM, a0, 2f
+  j fail
+
+2:
+  bne t2, t3, fail
+
+  csrr t2, mcause
+  bne t2, t1, fail
+
+  csrw mepc, t3
+  mret
+
+RVTEST_CODE_END
+
+  .data
+RVTEST_DATA_BEGIN
+
+  TEST_DATA
+
+RVTEST_DATA_END