[hatari-devel] VME access

[ Thread Index | Date Index | More lists.tuxfamily.org/hatari-devel Archives ]

To: hatari-devel@xxxxxxxxxxxxxxxxxxx
Subject: [hatari-devel] VME access
From: Eero Tamminen <oak@xxxxxxxxxxxxxx>
Date: Sun, 3 Jan 2021 00:51:12 +0200

Hi,

I'm thinking of making VME register access run-
time configurable, so that Hatari TT emulation can
be used with Linux.

Any comments on the attached patch to implement that?


	- Eero

commit 79d204d04be354b025006e655520abb44f783d86
Author: Eero Tamminen <oak@xxxxxxxxxxxxxx>
Date:   Sat Jan 2 21:04:39 2021 +0200

    Make MegaSTE/TT VME access error disabling run-time configurable
    
    Because it's needed for TOS MegaSTE detection, but causes Linux
    TT boot to fail, due to missing VME emulation.

diff --git a/doc/hatari.1 b/doc/hatari.1
index 8940400c..123d76e9 100644
--- a/doc/hatari.1
+++ b/doc/hatari.1
@@ -481,6 +481,13 @@ Select machine type (x = st, megast, ste, megaste, tt or falcon)
 .B \-\-blitter <bool>
 Enable blitter emulation (ST only)
 .TP
+.B \-\-vme\-errors <bool>
+Hatari doesn't emulate VME yet, and this controls whether access to
+VME registers causes errors.  TOS uses VME registers just to detect
+MegaSTE, so disable errors to support that (and to use 14MB of RAM on
+VME machines).  M68k Linux actually sets up SCU interrupts after
+detecting VME, so enable errors for Linux (MegaSTE/TT only)
+.TP
 .B \-\-dsp <x>
 Falcon DSP emulation (x = none, dummy or emu, Falcon only)
 .TP
diff --git a/doc/manual.html b/doc/manual.html
index fc8b5628..94f4ecde 100644
--- a/doc/manual.html
+++ b/doc/manual.html
@@ -997,6 +997,14 @@ megaste, tt or falcon)</p>
 <p class="parameter">--blitter
 &lt;bool&gt;</p>
 <p class="paramdesc">Enable blitter emulation (ST only)</p>
+<p class="parameter">--vme-errors &lt;bool&gt;</p>
+<p class="paramdesc">
+Hatari doesn't emulate VME yet, and this controls whether access to
+VME registers causes errors.  TOS uses VME registers just to detect
+MegaSTE, so disable errors to support that (and to use 14MB of RAM on
+VME machines). M68k Linux actually sets up SCU interrupts after
+detecting VME, so enable errors for Linux (MegaSTE/TT only)
+</p>
 <p class="parameter">--dsp &lt;x&gt;</p>
 <p class="paramdesc">Falcon DSP emulation (x = none, dummy
 or emu, Falcon only)</p>
diff --git a/src/configuration.c b/src/configuration.c
index d487469d..a418c715 100644
--- a/src/configuration.c
+++ b/src/configuration.c
@@ -602,6 +602,7 @@ static const struct Config_Tag configs_System[] =
 	{ "bCompatibleCpu", Bool_Tag, &ConfigureParams.System.bCompatibleCpu },
 	{ "nModelType", Int_Tag, &ConfigureParams.System.nMachineType },
 	{ "bBlitter", Bool_Tag, &ConfigureParams.System.bBlitter },
+	{ "bVmeErrors", Bool_Tag, &ConfigureParams.System.bVmeErrors },
 	{ "nDSPType", Int_Tag, &ConfigureParams.System.nDSPType },
 	{ "bPatchTimerD", Bool_Tag, &ConfigureParams.System.bPatchTimerD },
 	{ "bFastBoot", Bool_Tag, &ConfigureParams.System.bFastBoot },
@@ -899,6 +900,7 @@ void Configuration_SetDefault(void)
 	ConfigureParams.System.VideoTimingMode = VIDEO_TIMING_MODE_WS3;
 	ConfigureParams.System.bCompatibleCpu = true;
 	ConfigureParams.System.bBlitter = false;
+	ConfigureParams.System.bVmeErrors = false;
 	ConfigureParams.System.bPatchTimerD = false;
 	ConfigureParams.System.bFastBoot = false;
 	ConfigureParams.System.bFastForward = false;
@@ -1291,6 +1293,7 @@ void Configuration_MemorySnapShot_Capture(bool bSave)
 	MemorySnapShot_Store(&ConfigureParams.System.bCompatibleCpu, sizeof(ConfigureParams.System.bCompatibleCpu));
 	MemorySnapShot_Store(&ConfigureParams.System.nMachineType, sizeof(ConfigureParams.System.nMachineType));
 	MemorySnapShot_Store(&ConfigureParams.System.bBlitter, sizeof(ConfigureParams.System.bBlitter));
+	MemorySnapShot_Store(&ConfigureParams.System.bVmeErrors, sizeof(ConfigureParams.System.bVmeErrors));
 	MemorySnapShot_Store(&ConfigureParams.System.nDSPType, sizeof(ConfigureParams.System.nDSPType));
 	MemorySnapShot_Store(&bOldRealTimeClock, sizeof(bOldRealTimeClock));	/* TODO: Can be removed later */
 	MemorySnapShot_Store(&ConfigureParams.System.bPatchTimerD, sizeof(ConfigureParams.System.bPatchTimerD));
diff --git a/src/includes/configuration.h b/src/includes/configuration.h
index ace90653..25b58112 100644
--- a/src/includes/configuration.h
+++ b/src/includes/configuration.h
@@ -380,6 +380,7 @@ typedef struct
   bool bCompatibleCpu;            /* Prefetch mode */
   MACHINETYPE nMachineType;
   bool bBlitter;                  /* TRUE if Blitter is enabled */
+  bool bVmeErrors;                /* TRUE for MegaSTE/TT VME errors */
   DSPTYPE nDSPType;               /* how to "emulate" DSP */
   bool bPatchTimerD;
   bool bFastBoot;                 /* Enable to patch TOS for fast boot */
diff --git a/src/ioMem.c b/src/ioMem.c
index 6b3c92e8..7133c3d1 100644
--- a/src/ioMem.c
+++ b/src/ioMem.c
@@ -182,6 +182,20 @@ static void IoMem_FixVoidAccessForMegaST(void)
 	}
 }
 
+/*
+ * Disable errors on accessing VME registers
+ */
+static void IoMem_DisableVmeErrors(void)
+{
+	int addr;
+
+	/* TOS uses VME FF8E09 address to detect Mega-STE */
+	for (addr = 0xff8e01; addr <= 0xff8e0f; addr += 2)
+	{
+		pInterceptReadTable[addr - 0xff8000] = IoMem_ReadWithoutInterception;
+		pInterceptWriteTable[addr - 0xff8000] = IoMem_WriteWithoutInterception;
+	}
+}
 
 /**
  * Fix up the IO memory access table for the Mega STE.
@@ -202,13 +216,6 @@ static void IoMem_FixAccessForMegaSTE(void)
 	pInterceptReadTable[0xff8e23 - 0xff8000] = IoMem_VoidRead;
 	pInterceptWriteTable[0xff8e23 - 0xff8000] = IoMem_VoidWrite;
 
-	/* VME bus - we don't support it yet, but TOS uses FF8E09 to detect the Mega-STE */
-	for (addr = 0xff8e01; addr <= 0xff8e0f; addr += 2)
-	{
-		pInterceptReadTable[addr - 0xff8000] = IoMem_ReadWithoutInterception;
-		pInterceptWriteTable[addr - 0xff8000] = IoMem_WriteWithoutInterception;
-	}
-
 	/* The Mega-STE has a Z85C30 SCC serial port, too: */
 	for (addr = 0xff8c80; addr <= 0xff8c87; addr++)
 	{
@@ -329,6 +336,18 @@ void IoMem_Init(void)
 		IoMem_FixAccessForMegaSTE();
 
 
+	/*
+	 * VME bus - we don't support it yet, but whether accessing VME registers
+	 * on machines with VME (MegaSTE/TT) is run-time configurable because:
+	 * - TOS uses FF8E09 to detect Mega-STE, so VME address errors need to
+	 *   be disabled to support that
+	 * - Linux actually uses VME, so it fails to boot, if VME register accesses
+	 *   don't give errors, but VME doesn't work properly
+	 */
+	if (!ConfigureParams.System.bVmeErrors &&
+	    (Config_IsMachineTT() || Config_IsMachineMegaSTE()))
+		IoMem_DisableVmeErrors();
+
 	/* Set registers for Falcon */
 	if (Config_IsMachineFalcon())
 	{
diff --git a/src/ioMemTabTT.c b/src/ioMemTabTT.c
index 4de5f246..5c211206 100644
--- a/src/ioMemTabTT.c
+++ b/src/ioMemTabTT.c
@@ -180,6 +180,7 @@ const INTERCEPT_ACCESS_FUNC IoMemTable_TT[] =
 	{ 0xff8c80, 8, SCC_IoMem_ReadByte, SCC_IoMem_WriteByte },                               /* SCC */
 	{ 0xff8c88, 8, IoMem_VoidRead_00, IoMem_VoidWrite },                                    /* No bus error here */
 
+#if 0	/* set at run-time for MegaSTE & TT in ioMem.c */
 	{ 0xff8e01, 1, IoMem_ReadWithoutInterception, IoMem_WriteWithoutInterception },         /* SCU system interrupt mask */
 	{ 0xff8e03, 1, IoMem_ReadWithoutInterception, IoMem_WriteWithoutInterception },         /* SCU system interrupt state */
 	{ 0xff8e05, 1, IoMem_ReadWithoutInterception, IoMem_WriteWithoutInterception },         /* SCU system interrupter */
@@ -188,6 +189,7 @@ const INTERCEPT_ACCESS_FUNC IoMemTable_TT[] =
 	{ 0xff8e0b, 1, IoMem_ReadWithoutInterception, IoMem_WriteWithoutInterception },         /* SCU general purpose 2 */
 	{ 0xff8e0d, 1, IoMem_ReadWithoutInterception, IoMem_WriteWithoutInterception },         /* SCU VME interrupt mask */
 	{ 0xff8e0f, 1, IoMem_ReadWithoutInterception, IoMem_WriteWithoutInterception },         /* SCU VME interrupt state */
+#endif
 
 	{ 0xff9000, SIZE_WORD, IoMem_VoidRead, IoMem_VoidWrite },                /* No bus error here */
 	{ 0xff9200, SIZE_WORD, IoMemTabTT_ReadDIPSwitches, IoMem_VoidWrite },    /* DIP switches */
diff --git a/src/options.c b/src/options.c
index 1fa4232c..b54536a2 100644
--- a/src/options.c
+++ b/src/options.c
@@ -161,6 +161,7 @@ enum {
 #endif
 	OPT_MACHINE,		/* system options */
 	OPT_BLITTER,
+	OPT_VME_ERRORS,
 	OPT_DSP,
 	OPT_TIMERD,
 	OPT_FASTBOOT,
@@ -446,6 +447,8 @@ static const opt_t HatariOptions[] = {
 	  "<x>", "Select machine type (x = st/megast/ste/megaste/tt/falcon)" },
 	{ OPT_BLITTER,   NULL, "--blitter",
 	  "<bool>", "Use blitter emulation (ST only)" },
+	{ OPT_VME_ERRORS, NULL, "--vme-errors",
+	  "<bool>", "MegaSTE/TT VME access generates errors" },
 	{ OPT_DSP,       NULL, "--dsp",
 	  "<x>", "DSP emulation (x = none/dummy/emu, Falcon only)" },
 	{ OPT_TIMERD,    NULL, "--timer-d",
@@ -1971,6 +1974,9 @@ bool Opt_ParseParameters(int argc, const char * const argv[])
 			}
 			break;
 
+		case OPT_VME_ERRORS:
+			ok = Opt_Bool(argv[++i], OPT_VME_ERRORS, &ConfigureParams.System.bVmeErrors);
+			break;
 		case OPT_TIMERD:
 			ok = Opt_Bool(argv[++i], OPT_TIMERD, &ConfigureParams.System.bPatchTimerD);
 			break;

Follow-Ups:
- Re: [hatari-devel] VME access
  - From: Thomas Huth

Messages sorted by: [ date | thread ]
Prev by Date: Re: [hatari-devel] Shalll we remove deprecated features like SDL 1.2 now?
Next by Date: Re: [hatari-devel] About RAM size comments (commit 6c827e5)
Previous by thread: [PATCH] Tracing and run-time configuration for MegaSTE/TT VME/SCU regs access
Next by thread: Re: [hatari-devel] VME access

Mail converted by MHonArc 2.6.19+

http://listengine.tuxfamily.org/