ref: c3ba64f6935322f09b6de5c2285544fd471c605d
dir: /sys/src/games/gb/mem.c/
#include <u.h> #include <libc.h> #include <thread.h> #include "../eui.h" #include "dat.h" #include "fns.h" u8int *rom; u8int *romb, *vramb, *wramb, *eramb; u8int wram[32768], vram[16384], oam[256], reg[256]; u8int *back; u8int palm[128]; u32int pal[64]; int nrom, nback, nbackbank; u32int divclock; int prish; MBC3Timer timer, timerl; u8int dma; u32int white; u32int moncols[4]; Var memvars[] = {ARR(wram), ARR(vram), ARR(oam), ARR(reg), ARR(palm), VAR(clock), VAR(divclock), VAR(mode), VAR(dma), {nil, 0, 0}}; u8int regread(u8int a) { u8int v; switch(a){ case JOYP: v = reg[a] & 0xff; if((reg[a] & 0x10) == 0) v &= 0xf0 | ~keys; if((reg[a] & 0x20) == 0) v &= 0xf0 | ~(keys >> 4); return v; case DIV: return reg[DIV] + (clock - divclock >> 7 - ((mode & TURBO) != 0)); case TIMA: return timread(); case STAT: return reg[a] & 0xf8 | (reg[LYC] == ppuy) << 2 | ppustate; case LY: return ppuy; case BCPD: return palm[reg[BCPS] & 0x3f]; case OCPD: return palm[0x40 | reg[OCPS] & 0x3f]; case NR13: case NR23: case NR31: case NR33: case NR41: return 0xff; case NR14: case NR24: case NR34: case NR44: return reg[a] | 0xbf; case NR52: return apustatus; case NR11: case NR21: return reg[a] | 0x3f; case 0x30: case 0x31: case 0x32: case 0x33: case 0x34: case 0x35: case 0x36: case 0x37: case 0x38: case 0x39: case 0x3a: case 0x3b: case 0x3c: case 0x3d: case 0x3e: case 0x3f: return waveread(a & 0xf); default: return reg[a]; } } void colcol(int i, u16int v) { union { u8int c[4]; u32int l; } c; c.c[0] = v >> 7 & 0xf8; c.c[1] = v >> 2 & 0xf8; c.c[2] = v << 3; c.c[3] = 0; pal[i] = c.l; } void regwrite(u8int a, u8int v) { extern Event evhblank; int i; u8int u; switch(a){ case JOYP: v |= 0xcf; break; case SC: v |= 0x7c; break; case DIV: divclock = clock; v = 0; break; case TIMA: reg[a] = v; timerset(); return; case TAC: v |= 0xf8; timertac(v, 0); break; case STAT: v |= 0x80; if((v & IRQLYC) != 0 && ppuy == reg[LYC]) reg[IF] |= IRQLCDS; break; case LYC: if((reg[STAT] & IRQLYC) != 0 && ppuy == v) reg[IF] |= IRQLCDS; break; case LCDC: ppusync(); if((~v & reg[a] & LCDEN) != 0){ ppuy = 0; ppuw = 0; ppustate = 0; delevent(&evhblank); } if((v & ~reg[a] & LCDEN) != 0) addevent(&evhblank, 456*2); break; case SCY: case SCX: case WY: case WX: ppusync(); break; case VBK: if((mode & COL) == 0) goto ff; vramb = vram + ((v & 1) << 13); v |= 0xfe; break; case SVBK: if((mode & COL) == 0) goto ff; v &= 7; wramb = wram + (v + (v - 1 >> 3 & 1) << 12); v |= 0xf8; break; case BGP: case OBP0: case OBP1: if((mode & COL) != 0) break; ppusync(); i = a - BGP << 2; pal[i] = moncols[~v & 3]; pal[i+1] = moncols[~v >> 2 & 3]; pal[i+2] = moncols[~v >> 4 & 3]; pal[i+3] = moncols[~v >> 6 & 3]; break; case DMA: for(i = 0; i < 160; i++) oam[i] = memread(v << 8 | i); break; case BCPS: v |= 0x40; break; case OCPS: v |= 0x40; break; case BCPD: if((mode & COL) == 0) break; ppusync(); u = reg[BCPS] & 0x3f; palm[u] = v; colcol(u / 2, palm[u & 0xfe] | palm[u | 1] << 8); if((reg[BCPS] & 0x80) != 0) reg[BCPS] = reg[BCPS] + 1 - (u + 1 & 0x40); break; case OCPD: if((mode & COL) == 0) break; ppusync(); u = 0x40 | reg[OCPS] & 0x3f; palm[u] = v; colcol(u / 2, palm[u & 0xfe] | palm[u | 1] << 8); if((reg[OCPS] & 0x80) != 0) reg[OCPS] = reg[OCPS] + 1 - ((reg[OCPS] & 0x3f) + 1 & 0x40); break; case IF: v |= 0xe0; break; case IE: v &= 0x1f; break; case KEY1: v |= 0x7e; break; case HDMAC: if((mode & COL) == 0) goto ff; if(v & 0x80){ v &= 0x7f; dma = DMAHBLANK; }else if(dma){ v |= 0x80; dma = 0; }else dma = DMAREADY; break; case NR10: v |= 0x80; goto snd; case NR14: case NR24: v |= 0x38; goto snd; case NR30: v |= 0x7f; goto snd; case NR32: v |= 0x9f; goto snd; case NR41: v |= 0xc0; goto snd; case NR44: v |= 0x3f; goto snd; case NR52: v |= 0x70; goto snd; case NR11: case NR12: case NR13: case NR21: case NR22: case NR23: case NR31: case NR33: case NR34: case NR42: case NR43: case NR50: case NR51: snd: sndwrite(a, v); return; case SB: case TMA: break; case HDMASL: case HDMASH: case HDMADL: case HDMADH: case RP: if((mode & COL) == 0) goto ff; break; case 0x30: case 0x31: case 0x32: case 0x33: case 0x34: case 0x35: case 0x36: case 0x37: case 0x38: case 0x39: case 0x3a: case 0x3b: case 0x3c: case 0x3d: case 0x3e: case 0x3f: wavewrite(a & 0xf, v); return; default: if(a >= 0x80) break; ff: v = 0xff; } reg[a] = v; } static void nope(int p) { print("unimplemented mapper function %d (mapper %d)\n", p, mbc); } static int mbc0(int a, int) { if(a < 0) switch(a){ case INIT: if(nback != 0) eramb = back; return 0; case SAVE: case RSTR: return 0; case READ: return -1; default: nope(a); } return 0; } static int mbc1(int a, int v) { static u8int ramen, b0, b1, romram; static Var mbc1vars[] = {VAR(ramen), VAR(b0), VAR(b1), VAR(romram), {nil, 0, 0}}; u16int b; if(a < 0) switch(a){ case INIT: return 0; case SAVE: putvars(mbc1vars); break; case RSTR: getvars(mbc1vars); break; case READ: return -1; default: nope(a); } switch(a >> 13){ case 0: ramen = (v & 0xf) == 0xa; break; case 1: v &= 0x1f; b0 = v != 0 ? v : 1; break; case 2: b1 = v & 3; b1 %= nbackbank; break; case 3: romram = v & 1; break; } b = b0; if(!romram) b |= b1 << 5; b %= nrom >> 14; romb = rom + (b << 14); if(ramen) if(romram) eramb = back + (b1 << 13); else eramb = back; else eramb = nil; return 0; } static int mbc2(int a, int v) { static int ramen, b; static Var mbc2vars[] = {VAR(ramen), VAR(b), {nil, 0, 0}}; if(a < 0) switch(a){ case INIT: return 0; case SAVE: putvars(mbc2vars); return 0; case RSTR: getvars(mbc2vars); romb = rom + (b << 14); return 0; case READ: if(ramen) return back[a & 0x1ff]; return 0xff; default: nope(a); } if((a & 0xc100) == 0) ramen = (v & 0x0f) == 0x0a; else if((a & 0xc100) == 0x100){ b = v & 0x0f; if(b == 0) b++; b %= nrom >> 14; romb = rom + (b << 14); }else if((a >> 12) == 0xa && ramen) back[a & 0x1ff] = v | 0xf0; return 0; } void timerforward(MBC3Timer *t) { vlong n, nd; uint x; n = nsec(); nd = n - t->ns; if(nd < 0) return; if((t->dh & 0x40) != 0){ t->ns = n; return; } t->ns = n - nd % BILLION; x = t->sec + t->min * 60 + t->hr * 3600 + ((t->dh & 1) << 8 | t->dl) * 86400; x += nd / BILLION; t->sec = x % 60; x /= 60; t->min = x % 60; x /= 60; t->hr = x % 24; x /= 24; t->dl = x & 0xff; x >>= 8; t->dh = t->dh & 0xfe | x & 1; if(x >= 2) t->dh |= 0x80; } static int mbc3(int a, int v) { static u8int ramen, b0, b1, latch; static Var mbc3vars[] = {VAR(ramen), VAR(b0), VAR(b1), VAR(latch), VAR(timer.ns), VAR(timer.sec), VAR(timer.min), VAR(timer.hr), VAR(timer.dl), VAR(timer.dh), VAR(timerl.sec), VAR(timerl.min), VAR(timerl.hr), VAR(timerl.dl), VAR(timerl.dh), {nil, 0, 0}}; if(a < 0) switch(a){ case INIT: return 0; case SAVE: putvars(mbc3vars); return 0; case RSTR: getvars(mbc3vars); romb = rom + (b0 << 14); break; case READ: if(!ramen) return -1; switch(b1){ case 8: return timerl.sec; case 9: return timerl.min; case 10: return timerl.hr; case 11: return timerl.dl; case 12: return timerl.dh; } return -1; default: nope(a); } switch(a >> 13){ case 0: ramen = (v & 0xf) == 0xa; break; case 1: v &= 0x7f; b0 = v != 0 ? v : 1; b0 %= nrom >> 14; romb = rom + (b0 << 14); return 0; case 2: b1 = v & 15; break; case 3: if(latch == 0 && v == 1){ timerforward(&timer); timerl = timer; } latch = v; break; case 5: if(!ramen) return 0; switch(b1){ case 8: timerforward(&timer); timer.sec = v; break; case 9: timerforward(&timer); timer.min = v; break; case 10: timerforward(&timer); timer.hr = v; break; case 11: timerforward(&timer); timer.dl = v; break; case 12: timerforward(&timer); timer.dh = v; break; } return 0; } eramb = ramen && b1 < nbackbank ? back + (b1 << 13) : nil; return 0; } static int mbc5(int a, int v) { static u8int ramen, b1; static u16int b0; static Var mbc5vars[] = {VAR(ramen), VAR(b0), VAR(b1), {nil, 0, 0}}; if(a < 0) switch(a){ case INIT: return 0; case SAVE: putvars(mbc5vars); return 0; case RSTR: getvars(mbc5vars); break; case READ: return -1; default: nope(a); } switch(a >> 12){ case 0: case 1: ramen = (v & 0xf) == 0xa; break; case 2: b0 = b0 & 0x100 | v; break; case 3: b0 = b0 & 0xff | v << 8 & 0x100; break; case 4: b1 = v & 0xff; b1 %= nbackbank; break; } b0 %= nrom >> 14; romb = rom + (b0 << 14); eramb = ramen ? back + (b1 << 13) : nil; return 0; } int (*mappers[7])(int, int) = {mbc0, mbc1, mbc2, mbc3, mbc0, mbc5, mbc0}; int (*mapper)(int, int); u8int memread(u16int a) { switch(a >> 12){ case 0: case 1: case 2: case 3: return rom[a]; case 4: case 5: case 6: case 7: return romb[a - 0x4000]; case 8: case 9: return vramb[a - 0x8000]; case 10: case 11: if(eramb != nil) return eramb[a - 0xa000]; return mapper(READ, a); case 12: case 14: return wram[a & 0xfff]; case 13: return wramb[a & 0xfff]; case 15: if(a >= 0xff00) return regread(a); else if(a >= 0xfe00) return oam[a - 0xfe00]; } return 0xff; } void memwrite(u16int a, u8int v) { switch(a >> 12){ case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: mapper(a, v); return; case 8: case 9: vramb[a - 0x8000] = v; return; case 10: case 11: if(eramb != nil) eramb[a - 0xa000] = v; else mapper(a, v); writeback(); return; case 12: case 14: wram[a & 0xfff] = v; return; case 13: wramb[a & 0xfff] = v; return; case 15: if(a >= 0xff00) regwrite(a, v); else if(a >= 0xfe00) oam[a - 0xfe00] = v; return; } } void meminit(void) { union { u8int c[4]; u32int l; } c; c.c[0] = c.c[1] = c.c[2] = 0; c.c[3] = 1; for(; c.l != 1; prish++) c.l >>= 1; c.c[0] = c.c[1] = c.c[2] = 0xff; c.c[3] = 0; white = c.l; romb = rom + 0x4000; wramb = wram + 0x1000; vramb = vram; mapper = mappers[mbc]; mapper(INIT, 0); reg[LCDC] = 0x91; reg[VBK] = 0xfe; reg[SVBK] = 0xf8; reg[IF] = 0xe0; reg[HDMAC] = 0xff; } void memload(void) { int i; u8int v; if((mode & COL) != 0){ for(i = 0; i < 64; i++) colcol(i, palm[2*i] | palm[2*i+1] << 8); vramb = vram + ((reg[VBK] & 1) << 13); wramb = wram + (reg[SVBK] + (reg[SVBK] - 1 >> 3 & 1) << 12); }else{ v = reg[BGP]; pal[0] = moncols[~v & 3]; pal[1] = moncols[~v >> 2 & 3]; pal[2] = moncols[~v >> 4 & 3]; pal[3] = moncols[~v >> 6 & 3]; v = reg[OBP0]; pal[4] = moncols[~v & 3]; pal[5] = moncols[~v >> 2 & 3]; pal[6] = moncols[~v >> 4 & 3]; pal[7] = moncols[~v >> 6 & 3]; v = reg[OBP1]; pal[8] = moncols[~v & 3]; pal[9] = moncols[~v >> 2 & 3]; pal[10] = moncols[~v >> 4 & 3]; pal[11] = moncols[~v >> 6 & 3]; } } int dmastep(void) { int i; u16int sa, da; sa = (reg[HDMASL] | reg[HDMASH] << 8) & 0xfff0; da = (reg[HDMADL] | reg[HDMADH] << 8) & 0x1ff0 | 0x8000; for(i = 0; i < 16; i++) memwrite(da++, memread(sa++)); reg[HDMASL] += 16; if((reg[HDMASL] & 0xf0) == 0) reg[HDMASH]++; reg[HDMADL] += 16; if((reg[HDMADL] & 0xf0) == 0) reg[HDMADH]++; if(--reg[HDMAC] == 0xff) dma = 0; else if(dma & DMAHBLANK) dma &= ~DMAREADY; return 64; }