Add option to skip memtest in SRM

Previously the memtest was always skipped

Author: lenticularis39

src/AlphaCPU.cpp

@@ -399,6 +399,7 @@ void CAlphaCPU::init() {
   icache_enabled = true;
   flush_icache();
   icache_enabled = myCfg->get_bool_value("icache", false);
+  skip_memtest_hack = myCfg->get_bool_value("skip_memtest_hack", false);
 
   tbia(ACCESS_READ);
   tbia(ACCESS_EXEC);
@@ -560,75 +561,57 @@ void CAlphaCPU::check_state() {
   return;
 }
 
-inline void CAlphaCPU::skip_memtest()
-{
-    if (!(state.current_pc & U64(0x8b000)))
-    {
-        return;
-    }
+/**
+ * Skip SRM memtest.
+ *
+ * Hack that skips memory check in SRM.
+ **/
+inline void CAlphaCPU::skip_memtest() {
+  if (!(state.current_pc & U64(0x8b000))) {
+    return;
+  }
 
-    if (state.current_pc == U64(0x8bb90))
-    {
-        if (state.r[5] != U64(0xaaaaaaaaaaaaaaaa))
-        {
-            printf("wrong memory check skip!\n");
-        }
-        else
-        {
-            state.r[0] = state.r[4];
-        }
+  if (state.current_pc == U64(0x8bb90)) {
+    if (state.r[5] != U64(0xaaaaaaaaaaaaaaaa)) {
+      printf("wrong memory check skip!\n");
+    } else {
+      state.r[0] = state.r[4];
     }
+  }
 
-    if (state.current_pc == U64(0x8bbe0))
-    {
-        if (state.r[5] != U64(0xaaaaaaaaaaaaaaaa))
-        {
-            printf("wrong memory check skip!\n");
-        }
-        else
-        {
-            state.r[16] = 0;
-        }
+  if (state.current_pc == U64(0x8bbe0)) {
+    if (state.r[5] != U64(0xaaaaaaaaaaaaaaaa)) {
+      printf("wrong memory check skip!\n");
+    } else {
+      state.r[16] = 0;
     }
+  }
 
-    if (state.current_pc == U64(0x8bc28))
-    {
-        if (state.r[5] != U64(0xaaaaaaaaaaaaaaaa))
-        {
-            printf("wrong memory check skip!\n");
-        }
-        else
-        {
-            state.r[8] = state.r[4];
-        }
+  if (state.current_pc == U64(0x8bc28)) {
+    if (state.r[5] != U64(0xaaaaaaaaaaaaaaaa)) {
+      printf("wrong memory check skip!\n");
+    } else {
+      state.r[8] = state.r[4];
     }
+  }
 
-    if (state.current_pc == U64(0x8bc70))
-    {
-        if (state.r[7] != U64(0x5555555555555555))
-        {
-            printf("wrong memory check skip1!\n");
-        }
-        else
-        {
-            state.r[0] = 0;
-        }
+  if (state.current_pc == U64(0x8bc70)) {
+    if (state.r[7] != U64(0x5555555555555555)) {
+      printf("wrong memory check skip1!\n");
+    } else {
+      state.r[0] = 0;
     }
+  }
 
-    if (state.current_pc == U64(0x8bcb0))
-    {
-        if (state.r[7] != U64(0x5555555555555555))
-        {
-            printf("wrong memory check skip2!\n");
-        }
-        else
-        {
-            state.r[3] = state.r[4];
-        }
+  if (state.current_pc == U64(0x8bcb0)) {
+    if (state.r[7] != U64(0x5555555555555555)) {
+      printf("wrong memory check skip2!\n");
+    } else {
+      state.r[3] = state.r[4];
     }
+  }
 }
 
-
 /**
  * \brief Called each clock-cycle.
  *
@@ -682,7 +665,8 @@ void CAlphaCPU::execute() {
 #endif
   state.current_pc = state.pc;
 
-  skip_memtest();
+  if (skip_memtest_hack)
+    skip_memtest();
 
   // Service interrupts
   if (DO_ACTION) {

src/AlphaCPU.h

@@ -423,6 +423,7 @@ class CAlphaCPU : public CSystemComponent, public CRunnable {
   int vmspal_int_initiate_interrupt();
 
   bool icache_enabled;
+  bool skip_memtest_hack;
 
   // ... ... ...
   u64 cc_large;
@@ -565,7 +566,7 @@ class CAlphaCPU : public CSystemComponent, public CRunnable {
   u64 last_write_loc;
 #endif
 
-    void skip_memtest();
+  void skip_memtest();
 };
 
 /** Translate raw register (0..31) number to a number that takes PALshadow

src/es40-cfg.cpp

@@ -444,6 +444,23 @@ int main_cfg(int argc, char *argv[]) {
 
   icache_q.ask();
 
+  MultipleChoiceQuestion skip_memtest_hack_q;
+
+  skip_memtest_hack_q.setQuestion("Do you want to skip memtest on SRM start?");
+  skip_memtest_hack_q.setExplanation(
+      "This makes startup significantly faster, but may not work with some "
+      "versions of the firmware.");
+  skip_memtest_hack_q.setDefault("no");
+  skip_memtest_hack_q.addAnswer(
+      "yes", "true",
+      "Skip memtest hack enabled. CPU detects the instruction pointer where "
+      "the memtest starts and skips it.");
+  skip_memtest_hack_q.addAnswer("no", "false",
+                                "Skip memtest hack disabled. Firmware checks "
+                                "all available memory on startup.");
+
+  skip_memtest_hack_q.ask();
+
   NumberQuestion mhz_q;
 
   mhz_q.setQuestion("What should the reported speed of the CPU's be in MHz?");
@@ -462,6 +479,8 @@ int main_cfg(int argc, char *argv[]) {
     os << "  {\n";
     os << "    speed = " << mhz_q.getAnswer() << "M;\n";
     os << "    icache = " << icache_q.getAnswer() << ";\n";
+    os << "    skip_memtest_hack = " << skip_memtest_hack_q.getAnswer()
+       << ";\n";
     os << "  }\n\n";
   }