src/memory.c

Fri, 18 Apr 2014 01:34:20 -0600

author
andrew@localhost
date
Fri, 18 Apr 2014 01:34:20 -0600
changeset 151
b63a3999e2e7
parent 150
c19afa2c81db
permissions
-rw-r--r--

added RTC emulation (attempts to set the date are ignored, and the year is currently hardcoded to 1987 because UNIX PC SysV has a few Y2K bugs)

     1 #include <stdio.h>
     2 #include <stdlib.h>
     3 #include <stdint.h>
     4 #include <stdbool.h>
     5 #include <assert.h>
     6 #include "musashi/m68k.h"
     7 #include "state.h"
     8 #include "utils.h"
     9 #include "memory.h"
    11 // The value which will be returned if the CPU attempts to read from empty memory
    12 // TODO (FIXME?) - need to figure out if R/W ops wrap around. This seems to appease the UNIX kernel and P4TEST.
    13 #define EMPTY 0xFFFFFFFFUL
    14 //#define EMPTY 0x55555555UL
    15 //#define EMPTY 0x00000000UL
    17 /******************
    18  * Memory mapping
    19  ******************/
    21 #define MAPRAM(addr) (((uint16_t)state.map[addr*2] << 8) + ((uint16_t)state.map[(addr*2)+1]))
    23 static uint32_t map_address_debug(uint32_t addr)
    24 {
    25 	uint16_t page = (addr >> 12) & 0x3FF;
    27 	// Look it up in the map RAM and get the physical page address
    28 	uint32_t new_page_addr = MAPRAM(page) & 0x3FF;
    29 	return (new_page_addr << 12) + (addr & 0xFFF);
    30 }
    32 uint32_t mapAddr(uint32_t addr, bool writing)/*{{{*/
    33 {
    34 	if (addr < 0x400000) {
    35 		// RAM access. Check against the Map RAM
    36 		// Start by getting the original page address
    37 		uint16_t page = (addr >> 12) & 0x3FF;
    39 		// Look it up in the map RAM and get the physical page address
    40 		uint32_t new_page_addr = MAPRAM(page) & 0x3FF;
    42 		// Update the Page Status bits
    43 		uint8_t pagebits = (MAPRAM(page) >> 13) & 0x03;
    44 		// Pagebits --
    45 		//   0 = not present
    46 		//   1 = present but not accessed
    47 		//   2 = present, accessed (read from)
    48 		//   3 = present, dirty (written to)
    49 		switch (pagebits) {
    50 			case 0:
    51 				// Page not present
    52 				// This should cause a page fault
    53 				LOGS("Whoa! Pagebit update, when the page is not present!");
    54 				break;
    56 			case 1:
    57 				// Page present -- first access
    58 				state.map[page*2] &= 0x9F;	// turn off "present" bit (but not write enable!)
    59 				if (writing)
    60 					state.map[page*2] |= 0x60;		// Page written to (dirty)
    61 				else
    62 					state.map[page*2] |= 0x40;		// Page accessed but not written
    63 				break;
    65 			case 2:
    66 			case 3:
    67 				// Page present, 2nd or later access
    68 				if (writing)
    69 					state.map[page*2] |= 0x60;		// Page written to (dirty)
    70 				break;
    71 		}
    73 		// Return the address with the new physical page spliced in
    74 		return (new_page_addr << 12) + (addr & 0xFFF);
    75 	} else {
    76 		// I/O, VRAM or MapRAM space; no mapping is performed or required
    77 		// TODO: assert here?
    78 		return addr;
    79 	}
    80 }/*}}}*/
    82 MEM_STATUS checkMemoryAccess(uint32_t addr, bool writing, bool dma)/*{{{*/
    83 {
    84 	// Get the page bits for this page.
    85 	uint16_t page = (addr >> 12) & 0x3FF;
    86 	uint8_t pagebits = (MAPRAM(page) >> 13) & 0x07;
    88 	// Check page is present (but only for RAM zone)
    89 	if ((addr < 0x400000) && ((pagebits & 0x03) == 0)) {
    90 		LOG("Page not mapped in: addr %08X, page %04X, mapbits %04X", addr, page, MAPRAM(page));
    91 		return MEM_PAGEFAULT;
    92 	}
    94 	// Are we in Supervisor mode?
    95 	if (dma || (m68k_get_reg(NULL, M68K_REG_SR) & 0x2000))
    96 		// Yes. We can do anything we like.
    97 		return MEM_ALLOWED;
    99 	// If we're here, then we must be in User mode.
   100 	// Check that the user didn't access memory outside of the RAM area
   101 	if (addr >= 0x400000) {
   102 		LOGS("User accessed privileged memory");
   103 		return MEM_UIE;
   104 	}
   106 	// User attempt to access the kernel
   107 	// A19, A20, A21, A22 low (kernel access): RAM addr before paging; not in Supervisor mode
   108 	if (((addr >> 19) & 0x0F) == 0 && !(!writing && addr <= 0x1000)) {
   109 		LOGS("Attempt by user code to access kernel space");
   110 		return MEM_KERNEL;
   111 	}
   113 	// Check page is write enabled
   114 	if (writing && ((pagebits & 0x04) == 0)) {
   115 		LOG("Page not write enabled: inaddr %08X, page %04X, mapram %04X [%02X %02X], pagebits %d",
   116 				addr, page, MAPRAM(page), state.map[page*2], state.map[(page*2)+1], pagebits);
   117 		return MEM_PAGE_NO_WE;
   118 	}
   119 	// Page access allowed.
   120 	return MEM_ALLOWED;
   121 }/*}}}*/
   123 #define _ACCESS_CHECK_WR_BYTE(address)								\
   124 	do {															\
   125 		switch (st = checkMemoryAccess(address, true, false)) {			\
   126 			case MEM_ALLOWED:										\
   127 				/* Access allowed */								\
   128 				break;												\
   129 			case MEM_PAGEFAULT:										\
   130 				/* Page fault */									\
   131 				state.genstat = 0x8BFF | (state.pie ? 0x0400 : 0);	\
   132 				fault = true;										\
   133 				break;												\
   134 			case MEM_UIE:											\
   135 				/* User access to memory above 4MB */				\
   136 				state.genstat = 0x9AFF | (state.pie ? 0x0400 : 0);	\
   137 				fault = true;										\
   138 				break;												\
   139 			case MEM_KERNEL:										\
   140 			case MEM_PAGE_NO_WE:									\
   141 				/* kernel access or page not write enabled */		\
   142 				/* XXX: is this the correct value? */				\
   143 				state.genstat = 0x9BFF | (state.pie ? 0x0400 : 0);	\
   144 				fault = true;										\
   145 				break;												\
   146 		}															\
   147 	}while (0)
   151 /********************************************************
   152  * m68k memory read/write support functions for Musashi
   153  ********************************************************/
   155 /**
   156  * @brief	Check memory access permissions for a write operation.
   157  * @note	This used to be a single macro (merged with ACCESS_CHECK_RD), but
   158  * 			gcc throws warnings when you have a return-with-value in a void
   159  * 			function, even if the return-with-value is completely unreachable.
   160  * 			Similarly it doesn't like it if you have a return without a value
   161  * 			in a non-void function, even if it's impossible to ever reach the
   162  * 			return-with-no-value. UGH!
   163  */
   164 /*{{{ macro: ACCESS_CHECK_WR(address, bits)*/
   165 #define ACCESS_CHECK_WR(address, bits)								\
   166 	do {															\
   167 		bool fault = false;											\
   168 		MEM_STATUS st;												\
   169 		_ACCESS_CHECK_WR_BYTE(address);								\
   170 		if (!fault && bits == 32									\
   171 				&& ((address + 3) & ~0xfff) != ((address & ~0xfff))){	\
   172 			_ACCESS_CHECK_WR_BYTE(address + 3);						\
   173 		}															\
   174 		if (fault) {												\
   175 			if (bits >= 16)											\
   176 				state.bsr0 = 0x7C00;								\
   177 			else													\
   178 				state.bsr0 = (address & 1) ? 0x7E00 : 0x7D00;		\
   179 			state.bsr0 |= (address >> 16);							\
   180 			state.bsr1 = address & 0xffff;							\
   181 			LOG("Bus Error while writing, addr %08X, statcode %d", address, st);		\
   182 			if (state.ee) m68k_pulse_bus_error();					\
   183 			return;													\
   184 		}															\
   185 	} while (0)
   186 /*}}}*/
   188 #define _ACCESS_CHECK_RD_BYTE(address)									\
   189 	do {															\
   190 		switch (st = checkMemoryAccess(address, false, false)) {	\
   191 			case MEM_ALLOWED:										\
   192 				/* Access allowed */								\
   193 				break;												\
   194 			case MEM_PAGEFAULT:										\
   195 				/* Page fault */									\
   196 				state.genstat = 0xCBFF | (state.pie ? 0x0400 : 0);	\
   197 				fault = true;										\
   198 				break;												\
   199 			case MEM_UIE:											\
   200 				/* User access to memory above 4MB */				\
   201 				state.genstat = 0xDAFF | (state.pie ? 0x0400 : 0);	\
   202 				fault = true;										\
   203 				break;												\
   204 			case MEM_KERNEL:										\
   205 			case MEM_PAGE_NO_WE:									\
   206 				/* kernel access or page not write enabled */		\
   207 				/* XXX: is this the correct value? */				\
   208 				state.genstat = 0xDBFF | (state.pie ? 0x0400 : 0);	\
   209 				fault = true;										\
   210 				break;												\
   211 		}															\
   212 	} while (0)	
   214 /**
   215  * @brief Check memory access permissions for a read operation.
   216  * @note	This used to be a single macro (merged with ACCESS_CHECK_WR), but
   217  * 			gcc throws warnings when you have a return-with-value in a void
   218  * 			function, even if the return-with-value is completely unreachable.
   219  * 			Similarly it doesn't like it if you have a return without a value
   220  * 			in a non-void function, even if it's impossible to ever reach the
   221  * 			return-with-no-value. UGH!
   222  */
   223 /*{{{ macro: ACCESS_CHECK_RD(address, bits)*/
   224 #define ACCESS_CHECK_RD(address, bits)								\
   225 	do {															\
   226 		bool fault = false;											\
   227 		uint32_t faultAddr = address;								\
   228 		MEM_STATUS st;												\
   229 		_ACCESS_CHECK_RD_BYTE(address);								\
   230 		if (!fault && bits == 32									\
   231 				&& ((address + 2) & ~0xfff) != (address & ~0xfff)){	\
   232 			_ACCESS_CHECK_RD_BYTE(address + 2);						\
   233 			if (fault) faultAddr = address + 2;						\
   234 		}															\
   235 																	\
   236 		if (fault) {												\
   237 			if (bits >= 16)											\
   238 				state.bsr0 = 0x7C00;								\
   239 			else													\
   240 				state.bsr0 = (faultAddr & 1) ? 0x7E00 : 0x7D00;		\
   241 			state.bsr0 |= (faultAddr >> 16);							\
   242 			state.bsr1 = faultAddr & 0xffff;							\
   243 			LOG("Bus Error while reading, addr %08X, statcode %d", faultAddr, st);		\
   244 			if (state.ee) m68k_pulse_bus_error();					\
   245 			if (bits >= 32)											\
   246 				return EMPTY & 0xFFFFFFFF;									\
   247 			else													\
   248 				return EMPTY & ((1ULL << bits)-1);								\
   249 		}															\
   250 	} while (0)
   251 /*}}}*/
   253 bool access_check_dma(int reading)
   254 {
   255 	// Check memory access permissions
   256 	bool access_ok = false;
   257 	switch (checkMemoryAccess(state.dma_address, !reading, true)) {
   258 		case MEM_PAGEFAULT:
   259 			// Page fault
   260 			state.genstat = 0xABFF
   261 				| (reading ? 0x4000 : 0)
   262 				| (state.pie ? 0x0400 : 0);
   263 			access_ok = false;
   264 			break;
   266 		case MEM_UIE:
   267 			// User access to memory above 4MB
   268 			// FIXME? Shouldn't be possible with DMA... assert this?
   269 			state.genstat = 0xBAFF
   270 				| (reading ? 0x4000 : 0)
   271 				| (state.pie ? 0x0400 : 0);
   272 			access_ok = false;
   273 			break;
   275 		case MEM_KERNEL:
   276 		case MEM_PAGE_NO_WE:
   277 			// Kernel access or page not write enabled
   278 			/* XXX: is this correct? */
   279 			state.genstat = 0xBBFF
   280 				| (reading ? 0x4000 : 0)
   281 				| (state.pie ? 0x0400 : 0);
   282 			access_ok = false;
   283 			break;
   285 		case MEM_ALLOWED:
   286 			access_ok = true;
   287 			break;
   288 	}
   289 	if (!access_ok) {
   290 		state.bsr0 = 0x3C00;
   291 		state.bsr0 |= (state.dma_address >> 16);
   292 		state.bsr1 = state.dma_address & 0xffff;
   293 		if (state.ee) m68k_set_irq(7);
   294 		printf("BUS ERROR FROM DMA: genstat=%04X, bsr0=%04X, bsr1=%04X\n", state.genstat, state.bsr0, state.bsr1);
   295 	}
   296 	return (access_ok);
   297 }
   299 // Logging macros
   300 #define LOG_NOT_HANDLED_R(bits)															\
   301 	if (!handled) printf("unhandled read%02d, addr=0x%08X\n", bits, address);
   303 #define LOG_NOT_HANDLED_W(bits)															\
   304 	if (!handled) printf("unhandled write%02d, addr=0x%08X, data=0x%08X\n", bits, address, data);
   306 /********************************************************
   307  * I/O read/write functions
   308  ********************************************************/
   310 /**
   311  * Issue a warning if a read operation is made with an invalid size
   312  */
   313 inline static void ENFORCE_SIZE(int bits, uint32_t address, bool read, int allowed, char *regname)
   314 {
   315 	assert((bits == 8) || (bits == 16) || (bits == 32));
   316 	if ((bits & allowed) == 0) {
   317 		printf("WARNING: %s 0x%08X (%s) with invalid size %d!\n", read ? "read from" : "write to", address, regname, bits);
   318 	}
   319 }
   321 inline static void ENFORCE_SIZE_R(int bits, uint32_t address, int allowed, char *regname)
   322 {
   323 	ENFORCE_SIZE(bits, address, true, allowed, regname);
   324 }
   326 inline static void ENFORCE_SIZE_W(int bits, uint32_t address, int allowed, char *regname)
   327 {
   328 	ENFORCE_SIZE(bits, address, false, allowed, regname);
   329 }
   331 void IoWrite(uint32_t address, uint32_t data, int bits)/*{{{*/
   332 {
   333 	bool handled = false;
   335 	if ((address >= 0x400000) && (address <= 0x7FFFFF)) {
   336 		// I/O register space, zone A
   337 		switch (address & 0x0F0000) {
   338 			case 0x010000:				// General Status Register
   339 				if (bits == 16)
   340 					state.genstat = (data & 0xffff);
   341 				else if (bits == 8) {
   342 					if (address & 0)
   343 						state.genstat = data;
   344 					else
   345 						state.genstat = data << 8;
   346 				}
   347 				handled = true;
   348 				break;
   349 			case 0x030000:				// Bus Status Register 0
   350 				break;
   351 			case 0x040000:				// Bus Status Register 1
   352 				break;
   353 			case 0x050000:				// Phone status
   354 				break;
   355 			case 0x060000:				// DMA Count
   356 				ENFORCE_SIZE_W(bits, address, 16, "DMACOUNT");
   357 				state.dma_count = (data & 0x3FFF);
   358 				state.idmarw = ((data & 0x4000) == 0x4000);
   359 				state.dmaen = ((data & 0x8000) == 0x8000);
   360 				// This handles the "dummy DMA transfer" mentioned in the docs
   361 				// disabled because it causes the floppy test to fail
   362 #if 0
   363 				if (!state.idmarw){
   364 					if (access_check_dma(true)){
   365 						uint32_t newAddr = mapAddr(state.dma_address, true);
   366 						// RAM access
   367 						if (newAddr <= 0x1fffff)
   368 							WR16(state.base_ram, newAddr, state.base_ram_size - 1, 0xFF);
   369 						else if (address <= 0x3FFFFF)
   370 							WR16(state.exp_ram, newAddr - 0x200000, state.exp_ram_size - 1, 0xFF);
   371 					}
   372 				}
   373 #endif
   374 				state.dma_count++;
   375 				handled = true;
   376 				break;
   377 			case 0x070000:				// Line Printer Status Register
   378 				break;
   379 			case 0x080000:				// Real Time Clock
   380 				ENFORCE_SIZE_W(bits, address, 16, "RTCWRITE");
   381 				/*printf("IoWrite RTCWRITE %x\n", data);*/
   382 				tc8250_set_chip_enable(&state.rtc_ctx, data & 0x8000);
   383 				tc8250_set_address_latch_enable(&state.rtc_ctx, data & 0x4000);
   384 				tc8250_set_write_enable(&state.rtc_ctx, data & 0x2000);
   385 				tc8250_write_reg(&state.rtc_ctx, (data & 0x0F00) >> 8);
   386 				handled = true;
   387 				break;
   388 			case 0x090000:				// Phone registers
   389 				switch (address & 0x0FF000) {
   390 					case 0x090000:		// Handset relay
   391 					case 0x098000:
   392 						break;
   393 					case 0x091000:		// Line select 2
   394 					case 0x099000:
   395 						break;
   396 					case 0x092000:		// Hook relay 1
   397 					case 0x09A000:
   398 						break;
   399 					case 0x093000:		// Hook relay 2
   400 					case 0x09B000:
   401 						break;
   402 					case 0x094000:		// Line 1 hold
   403 					case 0x09C000:
   404 						break;
   405 					case 0x095000:		// Line 2 hold
   406 					case 0x09D000:
   407 						break;
   408 					case 0x096000:		// Line 1 A-lead
   409 					case 0x09E000:
   410 						break;
   411 					case 0x097000:		// Line 2 A-lead
   412 					case 0x09F000:
   413 						break;
   414 				}
   415 				break;
   416 			case 0x0A0000:				// Miscellaneous Control Register
   417 				ENFORCE_SIZE_W(bits, address, 16, "MISCCON");
   418 				// TODO: handle the ctrl bits properly
   419 				if (data & 0x8000){
   420 					state.timer_enabled = 1;
   421 				}else{
   422 					state.timer_enabled = 0;
   423 					state.timer_asserted = 0;
   424 				}
   425 				state.dma_reading = (data & 0x4000);
   426 				if (state.leds != ((~data & 0xF00) >> 8)) {
   427 					state.leds = (~data & 0xF00) >> 8;
   428 #ifdef SHOW_LEDS
   429 					printf("LEDs: %s %s %s %s\n",
   430 							(state.leds & 8) ? "R" : "-",
   431 							(state.leds & 4) ? "G" : "-",
   432 							(state.leds & 2) ? "Y" : "-",
   433 							(state.leds & 1) ? "R" : "-");
   434 #endif
   435 				}
   436 				handled = true;
   437 				break;
   438 			case 0x0B0000:				// TM/DIALWR
   439 				break;
   440 			case 0x0C0000:				// Clear Status Register
   441 				state.genstat = 0xFFFF;
   442 				state.bsr0 = 0xFFFF;
   443 				state.bsr1 = 0xFFFF;
   444 				handled = true;
   445 				break;
   446 			case 0x0D0000:				// DMA Address Register
   447 				if (address & 0x004000) {
   448 					// A14 high -- set most significant bits
   449 					state.dma_address = (state.dma_address & 0x1fe) | ((address & 0x3ffe) << 8);
   450 				} else {
   451 					// A14 low -- set least significant bits
   452 					state.dma_address = (state.dma_address & 0x3ffe00) | (address & 0x1fe);
   453 				}
   454 				handled = true;
   455 				break;
   456 			case 0x0E0000:				// Disk Control Register
   457 				{
   458 					bool fd_selected;
   459 					bool hd_selected;
   460 					ENFORCE_SIZE_W(bits, address, 16, "DISKCON");
   461 					// B7 = FDD controller reset
   462 					if ((data & 0x80) == 0) wd2797_reset(&state.fdc_ctx);
   463 					// B6 = drive 0 select
   464 					fd_selected = (data & 0x40) != 0;
   465 					// B5 = motor enable -- TODO
   466 					// B4 = HDD controller reset
   467 					if ((data & 0x10) == 0) wd2010_reset(&state.hdc_ctx);
   468 					// B3 = HDD0 select
   469 					hd_selected = (data & 0x08) != 0;
   470 					// B2,1,0 = HDD0 head select -- TODO?
   471 					if (hd_selected && !state.hd_selected){
   472 						state.fd_selected = false;
   473 						state.hd_selected = true;
   474 					}else if (fd_selected && !state.fd_selected){
   475 						state.hd_selected = false;
   476 						state.fd_selected = true;
   477 					}
   478 					handled = true;
   479 					break;
   480 				}
   481 			case 0x0F0000:				// Line Printer Data Register
   482 				break;
   483 		}
   484 	} else if ((address >= 0xC00000) && (address <= 0xFFFFFF)) {
   485 		// I/O register space, zone B
   486 		switch (address & 0xF00000) {
   487 			case 0xC00000:				// Expansion slots
   488 			case 0xD00000:
   489 				switch (address & 0xFC0000) {
   490 					case 0xC00000:		// Expansion slot 0
   491 					case 0xC40000:		// Expansion slot 1
   492 					case 0xC80000:		// Expansion slot 2
   493 					case 0xCC0000:		// Expansion slot 3
   494 					case 0xD00000:		// Expansion slot 4
   495 					case 0xD40000:		// Expansion slot 5
   496 					case 0xD80000:		// Expansion slot 6
   497 					case 0xDC0000:		// Expansion slot 7
   498 						fprintf(stderr, "NOTE: WR%d to expansion card space, addr=0x%08X, data=0x%08X\n", bits, address, data);
   499 						handled = true;
   500 						break;
   501 				}
   502 				break;
   503 			case 0xE00000:				// HDC, FDC, MCR2 and RTC data bits
   504 			case 0xF00000:
   505 				switch (address & 0x070000) {
   506 					case 0x000000:		// [ef][08]xxxx ==> WD2010 hard disc controller
   507 						wd2010_write_reg(&state.hdc_ctx, (address >> 1) & 7, data);
   508 						handled = true;
   509 						break;
   510 					case 0x010000:		// [ef][19]xxxx ==> WD2797 floppy disc controller
   511 						/*ENFORCE_SIZE_W(bits, address, 16, "FDC REGISTERS");*/
   512 						wd2797_write_reg(&state.fdc_ctx, (address >> 1) & 3, data);
   513 						handled = true;
   514 						break;
   515 					case 0x020000:		// [ef][2a]xxxx ==> Miscellaneous Control Register 2
   516 						// MCR2 - UNIX PC Rev. P5.1 HDD head select b3 and potential HDD#2 select
   517 						wd2010_write_reg(&state.hdc_ctx, UNIXPC_REG_MCR2, data);
   518 						handled = true;
   519 						break;
   520 					case 0x030000:		// [ef][3b]xxxx ==> Real Time Clock data bits
   521 						break;
   522 					case 0x040000:		// [ef][4c]xxxx ==> General Control Register
   523 						switch (address & 0x077000) {
   524 							case 0x040000:		// [ef][4c][08]xxx ==> EE
   525 								// Error Enable. If =0, Level7 intrs and bus errors are masked.
   526 								ENFORCE_SIZE_W(bits, address, 16, "EE");
   527 								state.ee = ((data & 0x8000) == 0x8000);
   528 								handled = true;
   529 								break;
   530 							case 0x041000:		// [ef][4c][19]xxx ==> PIE
   531 								ENFORCE_SIZE_W(bits, address, 16, "PIE");
   532 								state.pie = ((data & 0x8000) == 0x8000);
   533 								handled = true;
   534 								break;
   535 							case 0x042000:		// [ef][4c][2A]xxx ==> BP
   536 								break;
   537 							case 0x043000:		// [ef][4c][3B]xxx ==> ROMLMAP
   538 								ENFORCE_SIZE_W(bits, address, 16, "ROMLMAP");
   539 								state.romlmap = ((data & 0x8000) == 0x8000);
   540 								handled = true;
   541 								break;
   542 							case 0x044000:		// [ef][4c][4C]xxx ==> L1 MODEM
   543 								ENFORCE_SIZE_W(bits, address, 16, "L1 MODEM");
   544 								break;
   545 							case 0x045000:		// [ef][4c][5D]xxx ==> L2 MODEM
   546 								ENFORCE_SIZE_W(bits, address, 16, "L2 MODEM");
   547 								break;
   548 							case 0x046000:		// [ef][4c][6E]xxx ==> D/N CONNECT
   549 								ENFORCE_SIZE_W(bits, address, 16, "D/N CONNECT");
   550 								break;
   551 							case 0x047000:		// [ef][4c][7F]xxx ==> Whole screen reverse video
   552 								ENFORCE_SIZE_W(bits, address, 16, "WHOLE SCREEN REVERSE VIDEO");
   553 								break;
   554 						}
   555 					case 0x050000:		// [ef][5d]xxxx ==> 8274
   556 						break;
   557 					case 0x060000:		// [ef][6e]xxxx ==> Control regs
   558 						switch (address & 0x07F000) {
   559 							default:
   560 								break;
   561 						}
   562 						break;
   563 					case 0x070000:		// [ef][7f]xxxx ==> 6850 Keyboard Controller
   564 						// TODO: figure out which sizes are valid (probably just 8 and 16)
   565 						// ENFORCE_SIZE_W(bits, address, 16, "KEYBOARD CONTROLLER");
   566 						if (bits == 8) {
   567 							printf("KBD WR %02X => %02X\n", (address >> 1) & 3, data);
   568 							keyboard_write(&state.kbd, (address >> 1) & 3, data);
   569 							handled = true;
   570 						} else if (bits == 16) {
   571 							printf("KBD WR %02X => %04X\n", (address >> 1) & 3, data);
   572 							keyboard_write(&state.kbd, (address >> 1) & 3, data >> 8);
   573 							handled = true;
   574 						}
   575 						break;
   576 				}
   577 		}
   578 	}
   580 	LOG_NOT_HANDLED_W(bits);
   581 }/*}}}*/
   583 uint32_t IoRead(uint32_t address, int bits)/*{{{*/
   584 {
   585 	bool handled = false;
   586 	uint32_t data = EMPTY & 0xFFFFFFFF;
   588 	if ((address >= 0x400000) && (address <= 0x7FFFFF)) {
   589 		// I/O register space, zone A
   590 		switch (address & 0x0F0000) {
   591 			case 0x010000:				// General Status Register
   592 				/* ENFORCE_SIZE_R(bits, address, 16, "GENSTAT"); */
   593 				if (bits == 32) {
   594 					return ((uint32_t)state.genstat << 16) + (uint32_t)state.genstat;
   595 				} else if (bits == 16) {
   596 					return (uint16_t)state.genstat;
   597 				} else {
   598 					return (uint8_t)(state.genstat & 0xff);
   599 				}
   600 				break;
   601 			case 0x030000:				// Bus Status Register 0
   602 				ENFORCE_SIZE_R(bits, address, 16, "BSR0");
   603 				return ((uint32_t)state.bsr0 << 16) + (uint32_t)state.bsr0;
   604 				break;
   605 			case 0x040000:				// Bus Status Register 1
   606 				ENFORCE_SIZE_R(bits, address, 16, "BSR1");
   607 				return ((uint32_t)state.bsr1 << 16) + (uint32_t)state.bsr1;
   608 				break;
   609 			case 0x050000:				// Phone status
   610 				ENFORCE_SIZE_R(bits, address, 8 | 16, "PHONE STATUS");
   611 				break;
   612 			case 0x060000:				// DMA Count
   613 				// TODO: U/OERR- is always inactive (bit set)... or should it be = DMAEN+?
   614 				// Bit 14 is always unused, so leave it set
   615 				ENFORCE_SIZE_R(bits, address, 16, "DMACOUNT");
   616 				return (state.dma_count & 0x3fff) | 0xC000;
   617 				break;
   618 			case 0x070000:				// Line Printer Status Register
   619 				data = 0x00120012;	// no parity error, no line printer error, no irqs from FDD or HDD
   620 				data |= wd2797_get_irq(&state.fdc_ctx) ? 0x00080008 : 0;
   621 				data |= wd2010_get_irq(&state.hdc_ctx) ? 0x00040004 : 0;
   622 				return data;
   623 				break;
   624 			case 0x080000:				// Real Time Clock
   625 				printf("READ NOTIMP: Realtime Clock\n");
   626 				break;
   627 			case 0x090000:				// Phone registers
   628 				switch (address & 0x0FF000) {
   629 					case 0x090000:		// Handset relay
   630 					case 0x098000:
   631 						break;
   632 					case 0x091000:		// Line select 2
   633 					case 0x099000:
   634 						break;
   635 					case 0x092000:		// Hook relay 1
   636 					case 0x09A000:
   637 						break;
   638 					case 0x093000:		// Hook relay 2
   639 					case 0x09B000:
   640 						break;
   641 					case 0x094000:		// Line 1 hold
   642 					case 0x09C000:
   643 						break;
   644 					case 0x095000:		// Line 2 hold
   645 					case 0x09D000:
   646 						break;
   647 					case 0x096000:		// Line 1 A-lead
   648 					case 0x09E000:
   649 						break;
   650 					case 0x097000:		// Line 2 A-lead
   651 					case 0x09F000:
   652 						break;
   653 				}
   654 				break;
   655 			case 0x0A0000:				// Miscellaneous Control Register -- write only!
   656 				handled = true;
   657 				break;
   658 			case 0x0B0000:				// TM/DIALWR
   659 				break;
   660 			case 0x0C0000:				// Clear Status Register -- write only!
   661 				handled = true;
   662 				break;
   663 			case 0x0D0000:				// DMA Address Register
   664 				break;
   665 			case 0x0E0000:				// Disk Control Register
   666 				break;
   667 			case 0x0F0000:				// Line Printer Data Register
   668 				break;
   669 		}
   670 	} else if ((address >= 0xC00000) && (address <= 0xFFFFFF)) {
   671 		// I/O register space, zone B
   672 		switch (address & 0xF00000) {
   673 			case 0xC00000:				// Expansion slots
   674 			case 0xD00000:
   675 				switch (address & 0xFC0000) {
   676 					case 0xC00000:		// Expansion slot 0
   677 					case 0xC40000:		// Expansion slot 1
   678 					case 0xC80000:		// Expansion slot 2
   679 					case 0xCC0000:		// Expansion slot 3
   680 					case 0xD00000:		// Expansion slot 4
   681 					case 0xD40000:		// Expansion slot 5
   682 					case 0xD80000:		// Expansion slot 6
   683 					case 0xDC0000:		// Expansion slot 7
   684 						fprintf(stderr, "NOTE: RD%d from expansion card space, addr=0x%08X\n", bits, address);
   685 						handled = true;
   686 						break;
   687 				}
   688 				break;
   689 			case 0xE00000:				// HDC, FDC, MCR2 and RTC data bits
   690 			case 0xF00000:
   691 				switch (address & 0x070000) {
   692 					case 0x000000:		// [ef][08]xxxx ==> WD1010 hard disc controller
   693 						return (wd2010_read_reg(&state.hdc_ctx, (address >> 1) & 7));
   695 						break;
   696 					case 0x010000:		// [ef][19]xxxx ==> WD2797 floppy disc controller
   697 						/*ENFORCE_SIZE_R(bits, address, 16, "FDC REGISTERS");*/
   698 						return wd2797_read_reg(&state.fdc_ctx, (address >> 1) & 3);
   699 						break;
   700 					case 0x020000:		// [ef][2a]xxxx ==> Miscellaneous Control Register 2
   701 						break;
   702 					case 0x030000:		// [ef][3b]xxxx ==> Real Time Clock data bits
   703 						return (tc8250_read_reg(&state.rtc_ctx));
   704 					case 0x040000:		// [ef][4c]xxxx ==> General Control Register
   705 						switch (address & 0x077000) {
   706 							case 0x040000:		// [ef][4c][08]xxx ==> EE
   707 							case 0x041000:		// [ef][4c][19]xxx ==> PIE
   708 							case 0x042000:		// [ef][4c][2A]xxx ==> BP
   709 							case 0x043000:		// [ef][4c][3B]xxx ==> ROMLMAP
   710 							case 0x044000:		// [ef][4c][4C]xxx ==> L1 MODEM
   711 							case 0x045000:		// [ef][4c][5D]xxx ==> L2 MODEM
   712 							case 0x046000:		// [ef][4c][6E]xxx ==> D/N CONNECT
   713 								// All write-only registers... TODO: bus error?
   714 								handled = true;
   715 								break;
   716 							case 0x047000:		// [ef][4c][7F]xxx ==> Whole screen reverse video [FIXME: not in TRM]
   717 								break;
   718 						}
   719 						break;
   720 					case 0x050000:		// [ef][5d]xxxx ==> 8274
   721 						break;
   722 					case 0x060000:		// [ef][6e]xxxx ==> Control regs
   723 						switch (address & 0x07F000) {
   724 							default:
   725 								break;
   726 						}
   727 						break;
   728 					case 0x070000:		// [ef][7f]xxxx ==> 6850 Keyboard Controller
   729 						// TODO: figure out which sizes are valid (probably just 8 and 16)
   730 						//ENFORCE_SIZE_R(bits, address, 16, "KEYBOARD CONTROLLER");
   731 						{
   732 							if (bits == 8) {
   733 								return keyboard_read(&state.kbd, (address >> 1) & 3);
   734 							} else {
   735 								return keyboard_read(&state.kbd, (address >> 1) & 3) << 8;
   736 							}
   737 							return data;
   738 						}
   739 						break;
   740 				}
   741 		}
   742 	}
   744 	LOG_NOT_HANDLED_R(bits);
   746 	return data;
   747 }/*}}}*/
   750 /********************************************************
   751  * m68k memory read/write support functions for Musashi
   752  ********************************************************/
   755 static uint16_t ram_read_16(uint32_t address)
   756 {
   757 	if (address <= 0x1fffff) {
   758 		// Base memory wraps around
   759 		return RD16(state.base_ram, address, state.base_ram_size - 1);
   760 	} else {
   761 		if ((address <= (state.exp_ram_size + 0x200000 - 1)) && (address >= 0x200000)){
   762 			return RD16(state.exp_ram, address - 0x200000, state.exp_ram_size - 1);
   763 		}else
   764 			return EMPTY & 0xffff;
   765 	}
   766 }
   768 /**
   769  * @brief Read M68K memory, 32-bit
   770  */
   771 uint32_t m68k_read_memory_32(uint32_t address)/*{{{*/
   772 {
   773 	uint32_t data = EMPTY & 0xFFFFFFFF;
   775 	// If ROMLMAP is set, force system to access ROM
   776 	if (!state.romlmap)
   777 		address |= 0x800000;
   779 	// Check access permissions
   780 	ACCESS_CHECK_RD(address, 32);
   782 	if ((address >= 0x800000) && (address <= 0xBFFFFF)) {
   783 		// ROM access
   784 		return RD32(state.rom, address, ROM_SIZE - 1);
   785 	} else if (address <= 0x3fffff) {
   786 		// RAM access
   787 		uint32_t newAddr = mapAddr(address, false);
   788 		// Base memory wraps around
   789 		data = ((ram_read_16(newAddr) << 16) | 
   790 			ram_read_16(mapAddr(address + 2, false)));
   792 		return (data);
   793 	} else if ((address >= 0x400000) && (address <= 0x7FFFFF)) {
   794 		// I/O register space, zone A
   795 		switch (address & 0x0F0000) {
   796 			case 0x000000:				// Map RAM access
   797 				if (address > 0x4007FF) fprintf(stderr, "NOTE: RD32 from MapRAM mirror, addr=0x%08X\n", address);
   798 				return RD32(state.map, address, 0x7FF);
   799 				break;
   800 			case 0x020000:				// Video RAM
   801 				if (address > 0x427FFF) fprintf(stderr, "NOTE: RD32 from VideoRAM mirror, addr=0x%08X\n", address);
   802 				return RD32(state.vram, address, 0x7FFF);
   803 				break;
   804 			default:
   805 				return IoRead(address, 32);
   806 		}
   807 	} else {
   808 		return IoRead(address, 32);
   809 	}
   811 	return data;
   812 }/*}}}*/
   814 /**
   815  * @brief Read M68K memory, 16-bit
   816  */
   817 uint32_t m68k_read_memory_16(uint32_t address)/*{{{*/
   818 {
   819 	uint16_t data = EMPTY & 0xFFFF;
   821 	// If ROMLMAP is set, force system to access ROM
   822 	if (!state.romlmap)
   823 		address |= 0x800000;
   825 	// Check access permissions
   826 	ACCESS_CHECK_RD(address, 16);
   828 	if ((address >= 0x800000) && (address <= 0xBFFFFF)) {
   829 		// ROM access
   830 		data = RD16(state.rom, address, ROM_SIZE - 1);
   831 	} else if (address <= 0x3fffff) {
   832 		// RAM access
   833 		uint32_t newAddr = mapAddr(address, false);
   834 		if (newAddr <= 0x1fffff) {
   835 			// Base memory wraps around
   836 			return RD16(state.base_ram, newAddr, state.base_ram_size - 1);
   837 		} else {
   838 			if ((newAddr <= (state.exp_ram_size + 0x200000 - 1)) && (newAddr >= 0x200000))
   839 				return RD16(state.exp_ram, newAddr - 0x200000, state.exp_ram_size - 1);
   840 			else
   841 				return EMPTY & 0xffff;
   842 		}
   843 	} else if ((address >= 0x400000) && (address <= 0x7FFFFF)) {
   844 		// I/O register space, zone A
   845 		switch (address & 0x0F0000) {
   846 			case 0x000000:				// Map RAM access
   847 				if (address > 0x4007FF) fprintf(stderr, "NOTE: RD16 from MapRAM mirror, addr=0x%08X\n", address);
   848 				data = RD16(state.map, address, 0x7FF);
   849 				break;
   850 			case 0x020000:				// Video RAM
   851 				if (address > 0x427FFF) fprintf(stderr, "NOTE: RD16 from VideoRAM mirror, addr=0x%08X\n", address);
   852 				data = RD16(state.vram, address, 0x7FFF);
   853 				break;
   854 			default:
   855 				data = IoRead(address, 16);
   856 		}
   857 	} else {
   858 		data = IoRead(address, 16);
   859 	}
   861 	return data;
   862 }/*}}}*/
   864 /**
   865  * @brief Read M68K memory, 8-bit
   866  */
   867 uint32_t m68k_read_memory_8(uint32_t address)/*{{{*/
   868 {
   869 	uint8_t data = EMPTY & 0xFF;
   871 	// If ROMLMAP is set, force system to access ROM
   872 	if (!state.romlmap)
   873 		address |= 0x800000;
   875 	// Check access permissions
   876 	ACCESS_CHECK_RD(address, 8);
   878 	if ((address >= 0x800000) && (address <= 0xBFFFFF)) {
   879 		// ROM access
   880 		data = RD8(state.rom, address, ROM_SIZE - 1);
   881 	} else if (address <= 0x3fffff) {
   882 		// RAM access
   883 		uint32_t newAddr = mapAddr(address, false);
   884 		if (newAddr <= 0x1fffff) {
   885 			// Base memory wraps around
   886 			return RD8(state.base_ram, newAddr, state.base_ram_size - 1);
   887 		} else {
   888 			if ((newAddr <= (state.exp_ram_size + 0x200000 - 1)) && (newAddr >= 0x200000))
   889 				return RD8(state.exp_ram, newAddr - 0x200000, state.exp_ram_size - 1);
   890 			else
   891 				return EMPTY & 0xff;
   892 		}
   893 	} else if ((address >= 0x400000) && (address <= 0x7FFFFF)) {
   894 		// I/O register space, zone A
   895 		switch (address & 0x0F0000) {
   896 			case 0x000000:				// Map RAM access
   897 				if (address > 0x4007FF) fprintf(stderr, "NOTE: RD8 from MapRAM mirror, addr=0x%08X\n", address);
   898 				data = RD8(state.map, address, 0x7FF);
   899 				break;
   900 			case 0x020000:				// Video RAM
   901 				if (address > 0x427FFF) fprintf(stderr, "NOTE: RD8 from VideoRAM mirror, addr=0x%08X\n", address);
   902 				data = RD8(state.vram, address, 0x7FFF);
   903 				break;
   904 			default:
   905 				data = IoRead(address, 8);
   906 		}
   907 	} else {
   908 		data = IoRead(address, 8);
   909 	}
   911 	return data;
   912 }/*}}}*/
   915 static void ram_write_16(uint32_t address, uint32_t value)/*{{{*/
   916 {
   917 	if (address <= 0x1fffff) {
   918 		if (address < state.base_ram_size) {
   919 			WR16(state.base_ram, address, state.base_ram_size - 1, value);
   920 		}
   921 	} else {
   922 		if ((address - 0x200000) < state.exp_ram_size) {
   923 			WR16(state.exp_ram, address - 0x200000, state.exp_ram_size - 1, value);
   924 		}
   925 	}
   926 }
   928 /**
   929  * @brief Write M68K memory, 32-bit
   930  */
   931 void m68k_write_memory_32(uint32_t address, uint32_t value)/*{{{*/
   932 {
   933 	// If ROMLMAP is set, force system to access ROM
   934 	if (!state.romlmap)
   935 		address |= 0x800000;
   937 	// Check access permissions
   938 	ACCESS_CHECK_WR(address, 32);
   939 	if ((address >= 0x800000) && (address <= 0xBFFFFF)) {
   940 		// ROM access
   941 	} else if (address <= 0x3FFFFF) {
   942 		// RAM access
   943 		uint32_t newAddr = mapAddr(address, true);
   944 		ram_write_16(newAddr, (value & 0xffff0000) >> 16);
   945 		ram_write_16(mapAddr(address + 2, true), (value & 0xffff));
   946 	} else if ((address >= 0x400000) && (address <= 0x7FFFFF)) {
   947 		// I/O register space, zone A
   948 		switch (address & 0x0F0000) {
   949 			case 0x000000:				// Map RAM access
   950 				if (address > 0x4007FF) fprintf(stderr, "NOTE: WR32 to MapRAM mirror, addr=0x%08X\n", address);
   951 				WR32(state.map, address, 0x7FF, value);
   952 				break;
   953 			case 0x020000:				// Video RAM
   954 				if (address > 0x427FFF) fprintf(stderr, "NOTE: WR32 to VideoRAM mirror, addr=0x%08X\n", address);
   955 				WR32(state.vram, address, 0x7FFF, value);
   956 				break;
   957 			default:
   958 				IoWrite(address, value, 32);
   959 		}
   960 	} else {
   961 		IoWrite(address, value, 32);
   962 	}
   963 }/*}}}*/
   965 /**
   966  * @brief Write M68K memory, 16-bit
   967  */
   968 void m68k_write_memory_16(uint32_t address, uint32_t value)/*{{{*/
   969 {
   970 	// If ROMLMAP is set, force system to access ROM
   971 	if (!state.romlmap)
   972 		address |= 0x800000;
   974 	// Check access permissions
   975 	ACCESS_CHECK_WR(address, 16);
   977 	if ((address >= 0x800000) && (address <= 0xBFFFFF)) {
   978 		// ROM access
   979 	} else if (address <= 0x3FFFFF) {
   980 		// RAM access
   981 		uint32_t newAddr = mapAddr(address, true);
   983 		if (newAddr <= 0x1fffff) {
   984 			if (newAddr < state.base_ram_size) {
   985 				WR16(state.base_ram, newAddr, state.base_ram_size - 1, value);
   986 			}
   987 		} else {
   988 			if ((newAddr - 0x200000) < state.exp_ram_size) {
   989 				WR16(state.exp_ram, newAddr - 0x200000, state.exp_ram_size - 1, value);
   990 			}
   991 		}
   992 	} else if ((address >= 0x400000) && (address <= 0x7FFFFF)) {
   993 		// I/O register space, zone A
   994 		switch (address & 0x0F0000) {
   995 			case 0x000000:				// Map RAM access
   996 				if (address > 0x4007FF) fprintf(stderr, "NOTE: WR16 to MapRAM mirror, addr=0x%08X, data=0x%04X\n", address, value);
   997 				WR16(state.map, address, 0x7FF, value);
   998 				break;
   999 			case 0x020000:				// Video RAM
  1000 				if (address > 0x427FFF) fprintf(stderr, "NOTE: WR16 to VideoRAM mirror, addr=0x%08X, data=0x%04X\n", address, value);
  1001 				WR16(state.vram, address, 0x7FFF, value);
  1002 				break;
  1003 			default:
  1004 				IoWrite(address, value, 16);
  1006 	} else {
  1007 		IoWrite(address, value, 16);
  1009 }/*}}}*/
  1011 /**
  1012  * @brief Write M68K memory, 8-bit
  1013  */
  1014 void m68k_write_memory_8(uint32_t address, uint32_t value)/*{{{*/
  1016 	// If ROMLMAP is set, force system to access ROM
  1017 	if (!state.romlmap)
  1018 		address |= 0x800000;
  1020 	// Check access permissions
  1021 	ACCESS_CHECK_WR(address, 8);
  1023 	if ((address >= 0x800000) && (address <= 0xBFFFFF)) {
  1024 		// ROM access (read only!)
  1025 	} else if (address <= 0x3FFFFF) {
  1026 		// RAM access
  1027 		uint32_t newAddr = mapAddr(address, true);
  1028 		if (newAddr <= 0x1fffff) {
  1029 			if (newAddr < state.base_ram_size) {
  1030 				WR8(state.base_ram, newAddr, state.base_ram_size - 1, value);
  1032 		} else {
  1033 			if ((newAddr - 0x200000) < state.exp_ram_size) {
  1034 				WR8(state.exp_ram, newAddr - 0x200000, state.exp_ram_size - 1, value);
  1037 	} else if ((address >= 0x400000) && (address <= 0x7FFFFF)) {
  1038 		// I/O register space, zone A
  1039 		switch (address & 0x0F0000) {
  1040 			case 0x000000:				// Map RAM access
  1041 				if (address > 0x4007FF) fprintf(stderr, "NOTE: WR8 to MapRAM mirror, addr=0x%08X, data=0x%04X\n", address, value);
  1042 				WR8(state.map, address, 0x7FF, value);
  1043 				break;
  1044 			case 0x020000:				// Video RAM
  1045 				if (address > 0x427FFF) fprintf(stderr, "NOTE: WR8 to VideoRAM mirror, addr=0x%08X, data=0x%04X\n", address, value);
  1046 				WR8(state.vram, address, 0x7FFF, value);
  1047 				break;
  1048 			default:
  1049 				IoWrite(address, value, 8);
  1051 	} else {
  1052 		IoWrite(address, value, 8);
  1054 }/*}}}*/
  1057 // for the disassembler
  1058 uint32_t m68k_read_disassembler_32(uint32_t addr)
  1060 	if (addr < 0x400000) {
  1061 		uint32_t newAddrHigh, newAddrLow;
  1062 		newAddrHigh = map_address_debug(addr);
  1063 		newAddrLow = map_address_debug(addr + 2);
  1064 		return ((ram_read_16(newAddrHigh) << 16) | 
  1065 			ram_read_16(newAddrLow));
  1067 	} else {
  1068 		printf(">>> WARNING Disassembler RD32 out of range 0x%08X\n", addr);
  1069 		return EMPTY;
  1073 uint32_t m68k_read_disassembler_16(uint32_t addr)
  1075 	if (addr < 0x400000) {
  1076 		uint16_t page = (addr >> 12) & 0x3FF;
  1077 		uint32_t new_page_addr = MAPRAM(page) & 0x3FF;
  1078 		uint32_t newAddr = (new_page_addr << 12) + (addr & 0xFFF);
  1079 		if (newAddr <= 0x1fffff) {
  1080 			if (newAddr >= state.base_ram_size)
  1081 				return EMPTY & 0xffff;
  1082 			else
  1083 				return RD16(state.base_ram, newAddr, state.base_ram_size - 1);
  1084 		} else {
  1085 			if ((newAddr <= (state.exp_ram_size + 0x200000 - 1)) && (newAddr >= 0x200000))
  1086 				return RD16(state.exp_ram, newAddr - 0x200000, state.exp_ram_size - 1);
  1087 			else
  1088 				return EMPTY & 0xffff;
  1090 	} else {
  1091 		printf(">>> WARNING Disassembler RD16 out of range 0x%08X\n", addr);
  1092 		return EMPTY & 0xffff;
  1096 uint32_t m68k_read_disassembler_8 (uint32_t addr)
  1098 	if (addr < 0x400000) {
  1099 		uint16_t page = (addr >> 12) & 0x3FF;
  1100 		uint32_t new_page_addr = MAPRAM(page) & 0x3FF;
  1101 		uint32_t newAddr = (new_page_addr << 12) + (addr & 0xFFF);
  1102 		if (newAddr <= 0x1fffff) {
  1103 			if (newAddr >= state.base_ram_size)
  1104 				return EMPTY & 0xff;
  1105 			else
  1106 				return RD8(state.base_ram, newAddr, state.base_ram_size - 1);
  1107 		} else {
  1108 			if ((newAddr <= (state.exp_ram_size + 0x200000 - 1)) && (newAddr >= 0x200000))
  1109 				return RD8(state.exp_ram, newAddr - 0x200000, state.exp_ram_size - 1);
  1110 			else
  1111 				return EMPTY & 0xff;
  1113 	} else {
  1114 		printf(">>> WARNING Disassembler RD8 out of range 0x%08X\n", addr);
  1115 		return EMPTY & 0xff;