gearmulator

commit e71b1580acbd88776070139cccd57b7ac5ced25a
parent 97c49f763194fa7bbbb867df3e941311d8f23353
Author: dsp56300 <dsp56300@users.noreply.github.com>
Date:   Tue,  9 Jul 2024 22:36:04 +0200

use dynamic peripheral addressing only for startup code, disable for everything else

Diffstat:
M
source/xtLib/xtDSP.cpp
 | 
26
+++++++++++++++++++++++++-
M
source/xtLib/xtDSP.h
 | 
2
++

2 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/source/xtLib/xtDSP.cpp b/source/xtLib/xtDSP.cpp
@@ -8,6 +8,7 @@
 #endif
 
 #include "../mc68k/hdi08.h"
+#include "dsp56kEmu/aar.h"
 #include "dsp56kEmu/types.h"
 
 namespace xt
@@ -33,9 +34,32 @@ namespace xt
 
 		config.aguSupportBitreverse = true;
 		config.linkJitBlocks = true;
-		config.dynamicPeripheralAddressing = true;
+		config.dynamicPeripheralAddressing = false;
 		config.maxInstructionsPerBlock = 0;
 
+		// some startup code uses dynamic peripheral addressing, we allow this only for that code segment
+		config.getBlockConfig = [this](const dsp56k::TWord _pc) -> std::optional<dsp56k::JitConfig>
+		{
+			if(m_dynamicPeripheralAddressingStart == 0)
+			{
+				// find the following op:
+				// clr b M_AAR3,r2
+				const auto opA = m_dsp.memory().get(dsp56k::MemArea_P, _pc);
+				const auto opB = m_dsp.memory().get(dsp56k::MemArea_P, _pc + 1);
+				if(opA == 0x62f41b && opB == dsp56k::M_AAR3)
+				{
+					m_dynamicPeripheralAddressingStart = _pc;
+				}
+			}
+
+			// enable DPA for the address of the op we found + 16 words
+			if(_pc < m_dynamicPeripheralAddressingStart || _pc > m_dynamicPeripheralAddressingStart + 16)
+				return {};
+			auto c = m_dsp.getJit().getConfig();
+			c.dynamicPeripheralAddressing = true;
+			return c;
+		};
+
 		m_dsp.getJit().setConfig(config);
 
 		// fill P memory with something that reminds us if we jump to garbage
diff --git a/source/xtLib/xtDSP.h b/source/xtLib/xtDSP.h
@@ -72,5 +72,7 @@ namespace xt
 		uint32_t m_hdiHF01 = 0;	// uc => DSP
 
 		std::unique_ptr<dsp56k::DSPThread> m_thread;
+
+		uint32_t m_dynamicPeripheralAddressingStart = 0;
 	};
 }