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Removed 8000000H and later memory mapping for 386SX CPU. Still 0xFFFC…
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…0000 to 0xFFFFFFFF, and 0x81000000 to 0x8101FFFF are left regardless of the CPU type. It is because even if the CPU ID returns 386SX, Towns OS V2.1 tries to create R drive if CMOS setting is consistent with the CPU ID. If I want to use the same CMOS to test 386SX environment, I need sprite ram mapped to 0x81000000.
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@captainys
captainys committed Dec 6, 2024
1 parent 4b89281 commit c968897
Showing 1 changed file with 39 additions and 22 deletions.
61 changes: 39 additions & 22 deletions src/towns/memory/physmem.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -616,6 +616,11 @@ void TownsPhysicalMemory::SetUpMemoryAccess(unsigned int townsType,unsigned int
mappedSysROMAccess.SetCPUPointer(&cpu);
ResetSysROMDicROMMappingFlag(true,false); // This will set up memory access for 0xF8000 to 0xFFFFF and 0xD0000 to 0xDFFFF

if(TOWNSCPU_80386SX==cpuType && 0xA00000<state.RAM.size())
{
state.RAM.resize(0xA00000);
}

if(0x00100000<state.RAM.size())
{
mem.AddAccess(&mainRAMAccess,0x00100000,(unsigned int)state.RAM.size()-1);
Expand Down Expand Up @@ -682,23 +687,29 @@ void TownsPhysicalMemory::SetUpMemoryAccess(unsigned int townsType,unsigned int
martyROMAccess.SetPhysicalMemoryPointer(this);
martyROMAccess.SetCPUPointer(&cpu);

mem.AddAccess(&nativeDicROMAccess,TOWNSADDR_NATIVE_DICROM_BASE,TOWNSADDR_NATIVE_DICROM_END-1);
mem.AddAccess(&nativeCMOSRAMAccess,TOWNSADDR_NATIVE_CMOSRAM_BASE,TOWNSADDR_NATIVE_CMOSRAM_END-1);
mem.AddAccess(&sysROMAccess,TOWNSADDR_SYSROM_BASE,0xFFFFFFFF); // Even when machine ID is 386SX, the CPU core is actually 486. The reset instruction pointer needs to be at the end of 32-bit address space.

// Unless CMOS is cleared, Towns OS will try to put R drive from 81000000H regardless of the CPU type.
// To let 386SX run with the same CMOS setting, leave mapping of 81000000H.
mem.AddAccess(&spriteRAMAccess,TOWNSADDR_SPRITERAM_BASE,TOWNSADDR_SPRITERAM_END-1);
mem.AddAccess(&oldMemCardAccess,TOWNSADDR_MEMCARD_OLD_BASE,TOWNSADDR_MEMCARD_OLD_END-1);
mem.AddAccess(&JEIDA4MemCardAccess,TOWNSADDR_MEMCARD_JEIDA4_BASE,TOWNSADDR_MEMCARD_JEIDA4_END-1);
mem.AddAccess(&osROMAccess,TOWNSADDR_OSROM_BASE,TOWNSADDR_OSROM_END-1);
mem.AddAccess(&fontROMAccess,TOWNSADDR_FONT_BASE,TOWNSADDR_FONT_END-1);
mem.AddAccess(&font20ROMAccess,TOWNSADDR_FONT20_BASE,TOWNSADDR_FONT20_END-1);
mem.AddAccess(&waveRAMAccess,TOWNSADDR_WAVERAM_WINDOW_BASE,TOWNSADDR_WAVERAM_WINDOW_END-1);
mem.AddAccess(&sysROMAccess,TOWNSADDR_SYSROM_BASE,0xFFFFFFFF);

if(TOWNSTYPE_MARTY==townsType)
{
mem.AddAccess(&martyROMAccess,TOWNSADDR_MARTY_ROM0_BASE,TOWNSADDR_MARTY_ROM3_END-1);
}

if(TOWNSCPU_80386SX==cpuType)
if(TOWNSCPU_80386SX!=cpuType)
{
mem.AddAccess(&nativeDicROMAccess,TOWNSADDR_NATIVE_DICROM_BASE,TOWNSADDR_NATIVE_DICROM_END-1);
mem.AddAccess(&nativeCMOSRAMAccess,TOWNSADDR_NATIVE_CMOSRAM_BASE,TOWNSADDR_NATIVE_CMOSRAM_END-1);
mem.AddAccess(&oldMemCardAccess,TOWNSADDR_MEMCARD_OLD_BASE,TOWNSADDR_MEMCARD_OLD_END-1);
mem.AddAccess(&JEIDA4MemCardAccess,TOWNSADDR_MEMCARD_JEIDA4_BASE,TOWNSADDR_MEMCARD_JEIDA4_END-1);
mem.AddAccess(&osROMAccess,TOWNSADDR_OSROM_BASE,TOWNSADDR_OSROM_END-1);
mem.AddAccess(&fontROMAccess,TOWNSADDR_FONT_BASE,TOWNSADDR_FONT_END-1);
mem.AddAccess(&font20ROMAccess,TOWNSADDR_FONT20_BASE,TOWNSADDR_FONT20_END-1);
mem.AddAccess(&waveRAMAccess,TOWNSADDR_WAVERAM_WINDOW_BASE,TOWNSADDR_WAVERAM_WINDOW_END-1);
}
else
{
// Memory access for higher than 16MB address space is still neeeded in 80386SX mode since
// high address may be given to DMA, and DMA will translate address to low address.
Expand All @@ -722,12 +733,15 @@ void TownsPhysicalMemory::SetUpVRAMAccess(unsigned int cpuType,bool breakOnRead,
auto &mem=*memPtr;
if(true!=breakOnRead && true!=breakOnWrite)
{
mem.AddAccess(&VRAMAccess0,TOWNSADDR_VRAM0_BASE,TOWNSADDR_VRAM0_END-1);
mem.AddAccess(&VRAMAccess1,TOWNSADDR_VRAM1_BASE,TOWNSADDR_VRAM1_END-1);
mem.AddAccess(&VRAMAccessHighRes0,TOWNSADDR_VRAM_HIGHRES0_BASE,TOWNSADDR_VRAM_HIGHRES0_END-1); // For IIMX High Resolution Access.
mem.AddAccess(&VRAMAccessHighRes1,TOWNSADDR_VRAM_HIGHRES1_BASE,TOWNSADDR_VRAM_HIGHRES1_END-1); // For IIMX High Resolution Access.
mem.AddAccess(&VRAMAccessHighRes2,TOWNSADDR_VRAM_HIGHRES2_BASE,TOWNSADDR_VRAM_HIGHRES2_END-1); // For IIMX High Resolution Access.
if(TOWNSCPU_80386SX==cpuType)
if(TOWNSCPU_80386SX!=cpuType)
{
mem.AddAccess(&VRAMAccess0,TOWNSADDR_VRAM0_BASE,TOWNSADDR_VRAM0_END-1);
mem.AddAccess(&VRAMAccess1,TOWNSADDR_VRAM1_BASE,TOWNSADDR_VRAM1_END-1);
mem.AddAccess(&VRAMAccessHighRes0,TOWNSADDR_VRAM_HIGHRES0_BASE,TOWNSADDR_VRAM_HIGHRES0_END-1); // For IIMX High Resolution Access.
mem.AddAccess(&VRAMAccessHighRes1,TOWNSADDR_VRAM_HIGHRES1_BASE,TOWNSADDR_VRAM_HIGHRES1_END-1); // For IIMX High Resolution Access.
mem.AddAccess(&VRAMAccessHighRes2,TOWNSADDR_VRAM_HIGHRES2_BASE,TOWNSADDR_VRAM_HIGHRES2_END-1); // For IIMX High Resolution Access.
}
else
{
mem.AddAccess(&VRAMAccess0,TOWNSADDR_386SX_VRAM0_BASE,TOWNSADDR_386SX_VRAM0_END-1);
mem.AddAccess(&VRAMAccess1,TOWNSADDR_386SX_VRAM1_BASE,TOWNSADDR_386SX_VRAM1_END-1);
Expand All @@ -745,12 +759,15 @@ void TownsPhysicalMemory::SetUpVRAMAccess(unsigned int cpuType,bool breakOnRead,
VRAMAccessHighRes1Debug.breakOnWrite=breakOnWrite;
VRAMAccessHighRes2Debug.breakOnRead=breakOnRead;
VRAMAccessHighRes2Debug.breakOnWrite=breakOnWrite;
mem.AddAccess(&VRAMAccess0Debug,TOWNSADDR_VRAM0_BASE,TOWNSADDR_VRAM0_END-1);
mem.AddAccess(&VRAMAccess1Debug,TOWNSADDR_VRAM1_BASE,TOWNSADDR_VRAM1_END-1);
mem.AddAccess(&VRAMAccessHighRes0Debug,TOWNSADDR_VRAM_HIGHRES0_BASE,TOWNSADDR_VRAM_HIGHRES0_END-1); // For IIMX High Resolution Access.
mem.AddAccess(&VRAMAccessHighRes1Debug,TOWNSADDR_VRAM_HIGHRES1_BASE,TOWNSADDR_VRAM_HIGHRES1_END-1); // For IIMX High Resolution Access.
mem.AddAccess(&VRAMAccessHighRes2Debug,TOWNSADDR_VRAM_HIGHRES2_BASE,TOWNSADDR_VRAM_HIGHRES2_END-1); // For IIMX High Resolution Access.
if(TOWNSCPU_80386SX==cpuType)
if(TOWNSCPU_80386SX!=cpuType)
{
mem.AddAccess(&VRAMAccess0Debug,TOWNSADDR_VRAM0_BASE,TOWNSADDR_VRAM0_END-1);
mem.AddAccess(&VRAMAccess1Debug,TOWNSADDR_VRAM1_BASE,TOWNSADDR_VRAM1_END-1);
mem.AddAccess(&VRAMAccessHighRes0Debug,TOWNSADDR_VRAM_HIGHRES0_BASE,TOWNSADDR_VRAM_HIGHRES0_END-1); // For IIMX High Resolution Access.
mem.AddAccess(&VRAMAccessHighRes1Debug,TOWNSADDR_VRAM_HIGHRES1_BASE,TOWNSADDR_VRAM_HIGHRES1_END-1); // For IIMX High Resolution Access.
mem.AddAccess(&VRAMAccessHighRes2Debug,TOWNSADDR_VRAM_HIGHRES2_BASE,TOWNSADDR_VRAM_HIGHRES2_END-1); // For IIMX High Resolution Access.
}
else
{
mem.AddAccess(&VRAMAccess0Debug,TOWNSADDR_386SX_VRAM0_BASE,TOWNSADDR_386SX_VRAM0_END-1);
mem.AddAccess(&VRAMAccess1Debug,TOWNSADDR_386SX_VRAM1_BASE,TOWNSADDR_386SX_VRAM1_END-1);
Expand Down

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