1 files changed, 32 insertions, 4 deletions

diff --git a/isa/rv64si/scall.S b/isa/rv64si/scall.S
index 0579806..aea49b0 100644
--- a/isa/rv64si/scall.S
+++ b/isa/rv64si/scall.S
@@ -6,6 +6,8 @@
 #
 # Test syscall trap.
 #
+# If the pmp registers are implemented, then the pmp registers have 
+# to be configured before jumping to the privilaged modes
 
 #include "riscv_test.h"
 #include "test_macros.h"
@@ -26,16 +28,33 @@ RVTEST_CODE_BEGIN
 
   li TESTNUM, 2
 
-  # This is the expected trap code.
-  li t1, CAUSE_USER_ECALL
-
 #ifdef __MACHINE_MODE
   # If running in M mode, use mstatus.MPP to check existence of U mode.
   # Otherwise, if in S mode, then U mode must exist and we don't need to check.
+
+  la t0, user_mode_end
+  srli t0, t0, PMP_SHIFT
+  csrr t1, pmpcfg0
+  csrw pmpaddr0, t0
+  csrr t1, pmpaddr0
+  bne t0, t1, fail
+  li t0, (PMP_R | PMP_W | PMP_X)   # giving read, write and execute permissions
+  or t0, t0, PMP_TOR  # setting mode to TOR
+  li t1, 255
+  csrrc t1, pmpcfg0, t1
+  csrrs t1, pmpcfg0, t0
+  csrr  t1, pmpcfg0
+  andi  t1, t1, 255
+  bne t0, t1, fail
+.global no_pmp_implemented
+no_pmp_implemented:
   li t0, MSTATUS_MPP
   csrc mstatus, t0
   csrr t1, mstatus
   and t0, t0, t1
+  
+# This is the expected trap code.
+  li t1, CAUSE_USER_ECALL
   beqz t0, 1f
 
   # If U mode doesn't exist, mcause should indicate ECALL from M mode.
@@ -55,18 +74,27 @@ do_scall:
   scall
   j fail
 
+  .align 2
+  .global user_mode_end
+user_mode_end:
+  nop
+
   TEST_PASSFAIL
 
   .align 2
   .global stvec_handler
 stvec_handler:
   csrr t0, scause
-  bne t0, t1, fail
+  bne t0, t1, check_for_pmp
   la t2, do_scall
   csrr t0, sepc
   bne t0, t2, fail
   j pass
 
+check_for_pmp: 
+  li t1, CAUSE_ILLEGAL_INSTRUCTION
+  bne t0, t1, fail
+  j no_pmp_implemented
 RVTEST_CODE_END
 
   .data