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[/] [eco32/] [tags/] [eco32-0.22/] [sim/] [memory.c] - Rev 137
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/* * memory.c -- physical memory simulation */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <setjmp.h> #include "common.h" #include "console.h" #include "error.h" #include "except.h" #include "cpu.h" #include "memory.h" #include "timer.h" #include "dspkbd.h" #include "term.h" #include "disk.h" #include "output.h" #include "graph.h" static Byte *rom; static Byte *mem; static unsigned int memSize; static FILE *romImage; static unsigned int romSize; static FILE *progImage; static unsigned int progSize; Word memoryReadWord(Word pAddr) { Word data; if (pAddr <= memSize - 4) { data = ((Word) *(mem + pAddr + 0)) << 24 | ((Word) *(mem + pAddr + 1)) << 16 | ((Word) *(mem + pAddr + 2)) << 8 | ((Word) *(mem + pAddr + 3)) << 0; return data; } if (pAddr >= ROM_BASE && pAddr <= ROM_BASE + ROM_SIZE - 4) { data = ((Word) *(rom + (pAddr - ROM_BASE) + 0)) << 24 | ((Word) *(rom + (pAddr - ROM_BASE) + 1)) << 16 | ((Word) *(rom + (pAddr - ROM_BASE) + 2)) << 8 | ((Word) *(rom + (pAddr - ROM_BASE) + 3)) << 0; return data; } if ((pAddr & IO_DEV_MASK) == TIMER_BASE) { data = timerRead(pAddr & IO_REG_MASK); return data; } if ((pAddr & IO_DEV_MASK) == DISPLAY_BASE) { data = displayRead(pAddr & IO_REG_MASK); return data; } if ((pAddr & IO_DEV_MASK) == KEYBOARD_BASE) { data = keyboardRead(pAddr & IO_REG_MASK); return data; } if ((pAddr & IO_DEV_MASK) == TERM_BASE) { data = termRead(pAddr & IO_REG_MASK); return data; } if ((pAddr & IO_DEV_MASK) == DISK_BASE) { data = diskRead(pAddr & IO_REG_MASK); return data; } if ((pAddr & IO_DEV_MASK) == OUTPUT_BASE) { data = outputRead(pAddr & IO_REG_MASK); return data; } if ((pAddr & IO_DEV_MASK) >= GRAPH_BASE) { data = graphRead(pAddr & IO_GRAPH_MASK); return data; } /* throw bus timeout exception */ throwException(EXC_BUS_TIMEOUT); /* not reached */ data = 0; return data; } Half memoryReadHalf(Word pAddr) { Half data; if (pAddr <= memSize - 2) { data = ((Half) *(mem + pAddr + 0)) << 8 | ((Half) *(mem + pAddr + 1)) << 0; return data; } if (pAddr >= ROM_BASE && pAddr <= ROM_BASE + ROM_SIZE - 2) { data = ((Half) *(rom + (pAddr - ROM_BASE) + 0)) << 8 | ((Half) *(rom + (pAddr - ROM_BASE) + 1)) << 0; return data; } /* throw bus timeout exception */ throwException(EXC_BUS_TIMEOUT); /* not reached */ data = 0; return data; } Byte memoryReadByte(Word pAddr) { Byte data; if (pAddr <= memSize - 1) { data = ((Byte) *(mem + pAddr + 0)) << 0; return data; } if (pAddr >= ROM_BASE && pAddr <= ROM_BASE + ROM_SIZE - 1) { data = ((Byte) *(rom + (pAddr - ROM_BASE) + 0)) << 0; return data; } /* throw bus timeout exception */ throwException(EXC_BUS_TIMEOUT); /* not reached */ data = 0; return data; } void memoryWriteWord(Word pAddr, Word data) { if (pAddr <= memSize - 4) { *(mem + pAddr + 0) = (Byte) (data >> 24); *(mem + pAddr + 1) = (Byte) (data >> 16); *(mem + pAddr + 2) = (Byte) (data >> 8); *(mem + pAddr + 3) = (Byte) (data >> 0); return; } if ((pAddr & IO_DEV_MASK) == TIMER_BASE) { timerWrite(pAddr & IO_REG_MASK, data); return; } if ((pAddr & IO_DEV_MASK) == DISPLAY_BASE) { displayWrite(pAddr & IO_REG_MASK, data); return; } if ((pAddr & IO_DEV_MASK) == KEYBOARD_BASE) { keyboardWrite(pAddr & IO_REG_MASK, data); return; } if ((pAddr & IO_DEV_MASK) == TERM_BASE) { termWrite(pAddr & IO_REG_MASK, data); return; } if ((pAddr & IO_DEV_MASK) == DISK_BASE) { diskWrite(pAddr & IO_REG_MASK, data); return; } if ((pAddr & IO_DEV_MASK) == OUTPUT_BASE) { outputWrite(pAddr & IO_REG_MASK, data); return; } if ((pAddr & IO_DEV_MASK) >= GRAPH_BASE) { graphWrite(pAddr & IO_GRAPH_MASK, data); return; } /* throw bus timeout exception */ throwException(EXC_BUS_TIMEOUT); } void memoryWriteHalf(Word pAddr, Half data) { if (pAddr <= memSize - 2) { *(mem + pAddr + 0) = (Byte) (data >> 8); *(mem + pAddr + 1) = (Byte) (data >> 0); return; } /* throw bus timeout exception */ throwException(EXC_BUS_TIMEOUT); } void memoryWriteByte(Word pAddr, Byte data) { if (pAddr <= memSize - 1) { *(mem + pAddr + 0) = (Byte) (data >> 0); return; } /* throw bus timeout exception */ throwException(EXC_BUS_TIMEOUT); } void memoryReset(void) { unsigned int i; cPrintf("Resetting Memory...\n"); for (i = 0; i < memSize; i++) { mem[i] = rand(); } cPrintf("%6d MB RAM installed", memSize / M); if (progImage != NULL) { fseek(progImage, 0, SEEK_SET); if (fread(mem, progSize, 1, progImage) != 1) { error("cannot read program image file"); } cPrintf(", %d bytes loaded", progSize); } cPrintf(".\n"); for (i = 0; i < ROM_SIZE; i++) { rom[i] = 0xFF; } if (romImage != NULL) { fseek(romImage, 0, SEEK_SET); if (fread(rom, romSize, 1, romImage) != 1) { error("cannot read ROM image file"); } cPrintf("%6d KB ROM installed, %d bytes programmed.\n", ROM_SIZE / K, romSize); } } void memoryInit(unsigned int memorySize, char *progImageName, char *romImageName) { /* allocate RAM */ memSize = memorySize; mem = malloc(memSize); if (mem == NULL) { error("cannot allocate RAM"); } /* possibly load program image */ if (progImageName == NULL) { /* no program to load */ progImage = NULL; } else { /* load program */ progImage = fopen(progImageName, "rb"); if (progImage == NULL) { error("cannot open program file '%s'", progImageName); } fseek(progImage, 0, SEEK_END); progSize = ftell(progImage); if (progSize > memSize) { error("program file too big"); } /* do actual loading of image in memoryReset() */ } /* allocate ROM */ rom = malloc(ROM_SIZE); if (rom == NULL) { error("cannot allocate ROM"); } /* possibly load ROM image */ if (romImageName == NULL) { /* no ROM to plug in */ romImage = NULL; } else { /* plug in ROM */ romImage = fopen(romImageName, "rb"); if (romImage == NULL) { error("cannot open ROM image '%s'", romImageName); } fseek(romImage, 0, SEEK_END); romSize = ftell(romImage); if (romSize > ROM_SIZE) { error("ROM image too big"); } /* do actual loading of image in memoryReset() */ } memoryReset(); } void memoryExit(void) { free(mem); free(rom); }
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