dsp_rom: Remove illegal use of AX with SRS

Source/Core/Core/DSP/DSPCore.cpp

@@ -33,7 +33,7 @@ static bool VerifyRoms(const SDSP& dsp)
     u32 hash_drom;  // dsp_coef.bin
   };
 
-  static const std::array<DspRomHashes, 6> known_roms = {{
+  static const std::array<DspRomHashes, 7> known_roms = {{
       // Official Nintendo ROM
       {0x66f334fe, 0xf3b93527},
 
@@ -52,6 +52,9 @@ static bool VerifyRoms(const SDSP& dsp)
 
       // above with fix to skip bootucode_ax when running from ROM entrypoint
       {0x128ea7a2, 0xa4a575f5},
+
+      // above with fixes for invalid use of SRS instruction
+      {0xe789b5a5, 0xa4a575f5},
   }};
 
   const u32 hash_irom =
@@ -69,28 +72,30 @@ static bool VerifyRoms(const SDSP& dsp)
 
   if (rom_idx < 0)
   {
-    if (AskYesNoFmtT("Your DSP ROMs have incorrect hashes.\n"
+    if (AskYesNoFmtT("Your DSP ROMs have incorrect hashes.\n\n"
+                     "Delete the dsp_rom.bin and dsp_coef.bin files in the GC folder in the Global "
+                     "User Directory to use the free DSP ROM, or replace them with good dumps from "
+                     "a real GameCube/Wii.\n\n"
                      "Would you like to stop now to fix the problem?\n"
                      "If you select \"No\", audio might be garbled."))
+    {
       return false;
+    }
   }
 
-  if (rom_idx == 1)
+  if (rom_idx >= 1 && rom_idx <= 5)
   {
-    Host::OSD_AddMessage("You are using an old free DSP ROM made by the Dolphin Team.", 6000);
-    Host::OSD_AddMessage("Only games using the Zelda UCode will work correctly.", 6000);
-  }
-  else if (rom_idx == 2 || rom_idx == 3)
-  {
-    Host::OSD_AddMessage("You are using a free DSP ROM made by the Dolphin Team.", 8000);
-    Host::OSD_AddMessage("All Wii games will work correctly, and most GameCube games", 8000);
-    Host::OSD_AddMessage("should also work fine, but the GBA/CARD UCodes will not work.", 8000);
-  }
-  else if (rom_idx == 4)
-  {
-    Host::OSD_AddMessage("You are using a free DSP ROM made by the Dolphin Team.", 8000);
-    Host::OSD_AddMessage("All Wii games will work correctly, and most GameCube games", 8000);
-    Host::OSD_AddMessage("should also work fine, but the CARD UCode will not work.", 8000);
+    if (AskYesNoFmtT(
+            "You are using an old free DSP ROM made by the Dolphin Team.\n"
+            "Due to emulation accuracy improvements, this ROM no longer works correctly.\n\n"
+            "Delete the dsp_rom.bin and dsp_coef.bin files in the GC folder in the Global "
+            "User Directory to use the most recent free DSP ROM, or replace them with "
+            "good dumps from a real GameCube/Wii.\n\n"
+            "Would you like to stop now to fix the problem?\n"
+            "If you select \"No\", audio might be garbled."))
+    {
+      return false;
+    }
   }
 
   return true;

docs/DSP/free_dsp_rom/dsp_rom.ds

@@ -86,11 +86,11 @@ WARNPC 0x8b
 ORG 0x8b
 ; called by GBA ucode
 dram_to_cpu:
-    srs @DSMAH, $AX0.H
-    srs @DSMAL, $AX0.L
+    sr @DSMAH, $AX0.H
+    sr @DSMAL, $AX0.L
     si @DSCR, #0x1
-    srs @DSPA, $AX1.H
-    srs @DSBL, $AX1.L
+    sr @DSPA, $AX1.H
+    sr @DSBL, $AX1.L
     call wait_dma+#IROM_BASE
     ret
 
@@ -108,11 +108,11 @@ ORG 0xbc
 ; called by GBA ucode
 bootucode_ax:
     lris $AC0.M, #0
-    srs  @DSCR, $AC0.M
-    srs  @DSMAH, $AX0.H
-    srs  @DSMAL, $AX0.L
-    srs  @DSPA, $AX1.H
-    srs  @DSBL, $AX1.L
+    srs @DSCR, $AC0.M
+    sr  @DSMAH, $AX0.H
+    sr  @DSMAL, $AX0.L
+    sr  @DSPA, $AX1.H
+    sr  @DSBL, $AX1.L
     call wait_dma+#IROM_BASE
 
 bootucode_ix:

docs/DSP/free_dsp_rom/dsp_rom_readme.txt

@@ -1,3 +1,13 @@
+Legal GC/WII DSP IROM replacement (v0.4)
+-------------------------------------------------------
+
+- irom: Minor accuracy and documentation improvements
+- irom: Remove use of SRS instruction with AX registers, as those instructions
+  do not actually exist
+
+Tilka, Pokechu22
+17/aug/2021
+
 Legal GC/WII DSP IROM replacement (v0.3.1)
 -------------------------------------------------------