[test] Ignore bus integrity alert for scrambled SRAM test

sw/device/tests/BUILD

@@ -7386,6 +7386,7 @@ opentitan_test(
         "//sw/device/lib/testing:flash_ctrl_testutils",
         "//sw/device/lib/testing:rstmgr_testutils",
         "//sw/device/lib/testing:sram_ctrl_testutils",
+        "//sw/device/lib/testing/test_framework:ottf_alerts",
         "//sw/device/lib/testing/test_framework:ottf_main",
     ],
 )

sw/device/tests/sram_ctrl_scrambled_access_test.c

@@ -16,6 +16,7 @@
 #include "sw/device/lib/testing/rstmgr_testutils.h"
 #include "sw/device/lib/testing/sram_ctrl_testutils.h"
 #include "sw/device/lib/testing/test_framework/check.h"
+#include "sw/device/lib/testing/test_framework/ottf_alerts.h"
 #include "sw/device/lib/testing/test_framework/ottf_main.h"
 
 #include "hw/top_earlgrey/sw/autogen/top_earlgrey.h"
@@ -126,6 +127,22 @@ static const uint32_t kRamTestPattern2[kTestBufferSizeWords] = {
  */
 static const uint8_t kBackdoorExpectedBytes[kTestBufferSizeBytes];
 
+static bool expect_ecc_errors(void) {
+  switch (kDeviceType) {
+    case kDeviceFpgaCw305:
+    case kDeviceFpgaCw310:
+      return false;
+    case kDeviceFpgaCw340:
+    case kDeviceSilicon:
+    case kDeviceSimDV:
+    case kDeviceSimVerilator:
+      return true;
+    default:
+      CHECK(false, "Device type not handled: %d", kDeviceType);
+      return false;
+  }
+}
+
 /**
  * Performs scrambling, saves the test relevant data and resets the system.
  *
@@ -148,6 +165,14 @@ static noreturn void main_sram_scramble(void) {
     copy_len += sizeof(reference_frame->backdoor);
   }
 
+  // If we expect ECC errors from copying our pattern buffers then we have to
+  // disable the fatal alert associated with bus integrity checks. This is a
+  // fatal alert so we cannot "expect" it.
+  if (expect_ecc_errors()) {
+    CHECK_STATUS_OK(
+        ottf_alerts_ignore_alert(kTopEarlgreyAlertIdRvCoreIbexFatalHwErr));
+  }
+
   asm volatile(
       // Save the tests frames addresses before the scrambling.
       "lw a2, 0(%[mainFrame])                                        \n"
@@ -256,6 +281,22 @@ static void execute_main_sram_test(void) {
 }
 
 static void check_sram_data(scramble_test_frame *mem_frame) {
+  // Decide whether to perform ECC error count checks after memory is scrambled.
+  //
+  // This is not done on CW305/CW310 FPGAs because interrupts for ECC errors are
+  // only triggered when the SecureIbex parameter is enabled. This parameter is
+  // disabled for these boards due to resource constraints. On CW340 and the
+  // other targets, this parameter is enabled.
+  bool check_ecc_errors = expect_ecc_errors();
+
+  // If we expect ECC errors from copying our pattern buffers then we have to
+  // disable the fatal alert associated with bus integrity checks. This is a
+  // fatal alert so we cannot "expect" it.
+  if (check_ecc_errors) {
+    CHECK_STATUS_OK(
+        ottf_alerts_ignore_alert(kTopEarlgreyAlertIdRvCoreIbexFatalHwErr));
+  }
+
   LOG_INFO("Checking addr 0x%x", mem_frame->pattern);
   uint32_t tmp_buffer[kTestBufferSizeWords];
   memcpy(tmp_buffer, (const uint8_t *)mem_frame->pattern, sizeof(tmp_buffer));
@@ -265,29 +306,6 @@ static void check_sram_data(scramble_test_frame *mem_frame) {
   CHECK_ARRAYS_NE((uint32_t *)tmp_buffer, kRamTestPattern2,
                   kTestBufferSizeWords);
 
-  // Decide whether to perform ECC error count checks after memory is scrambled.
-  //
-  // This is not done on CW305/CW310 FPGAs because interrupts for ECC errors are
-  // only triggered when the SecureIbex parameter is enabled. This parameter is
-  // disabled for these boards due to resource constraints. On CW340 and the
-  // other targets, this parameter is enabled.
-  bool check_ecc_errors = false;
-  switch (kDeviceType) {
-    case kDeviceFpgaCw305:
-    case kDeviceFpgaCw310:
-      check_ecc_errors = false;
-      break;
-    case kDeviceFpgaCw340:
-    case kDeviceSilicon:
-    case kDeviceSimDV:
-    case kDeviceSimVerilator:
-      check_ecc_errors = true;
-      break;
-    default:
-      CHECK(false, "Device type not handled: %d", kDeviceType);
-      return;
-  }
-
   if (check_ecc_errors) {
     LOG_INFO("Checking ECC error count of %d",
              reference_frame->ecc_error_counter);