1 // Copyright 2003 Brian Alliet
2 // Based on org.xwt.imp.MIPS by Adam Megacz
3 // Portions Copyright 2003 Adam Megacz
7 import org.xwt.mips.util.*;
10 public class Interpreter extends UnixRuntime {
12 private int[] registers = new int[32];
15 // Floating Point Registers
16 private int[] fpregs = new int[32];
18 // 23 - conditional bit
20 // 12-17 - cause bits (unimplemented)
21 // 7-11 - enables bits (unimplemented)
22 // 2-6 - flags (unimplemented)
23 // 0-1 - rounding mode (only implemented for fixed point conversions)
28 // The filename if the binary we're running
30 private ELF.Symtab symtab;
32 // Register Operations
33 private final void setFC(boolean b) { fcsr = (fcsr&~0x800000) | (b ? 0x800000 : 0x000000); }
34 private final int roundingMode() { return fcsr & 3; /* bits 0-1 */ }
35 private final double getDouble(int r) {
36 return Double.longBitsToDouble(((fpregs[r+1]&0xffffffffL) << 32) | (fpregs[r]&0xffffffffL));
38 private final void setDouble(int r, double d) {
39 long l = Double.doubleToLongBits(d);
40 fpregs[r+1] = (int)(l >>> 32); fpregs[r] = (int)l;
42 private final float getFloat(int r) { return Float.intBitsToFloat(fpregs[r]); }
43 private final void setFloat(int r, float f) { fpregs[r] = Float.floatToRawIntBits(f); }
45 protected void _execute() throws ExecutionException {
48 } catch(ExecutionException e) {
49 e.setLocation(toHex(pc) + ": " + sourceLine(pc));
55 // the return value is meaningless, its just to catch people typing "return" by accident
56 private final int runSome() throws FaultException,ExecutionException {
65 insn = readPages[pc>>>PAGE_SHIFT][(pc>>>2)&PAGE_WORDS-1];
66 } catch (RuntimeException e) {
70 int op = (insn >>> 26) & 0xff; // bits 26-31
71 int rs = (insn >>> 21) & 0x1f; // bits 21-25
72 int rt = (insn >>> 16) & 0x1f; // bits 16-20
73 int ft = (insn >>> 16) & 0x1f;
74 int rd = (insn >>> 11) & 0x1f; // bits 11-15
75 int fs = (insn >>> 11) & 0x1f;
76 int shamt = (insn >>> 6) & 0x1f; // bits 6-10
77 int fd = (insn >>> 6) & 0x1f;
78 int subcode = insn & 0x3f; // bits 0-5
80 int jumpTarget = (insn & 0x03ffffff); // bits 0-25
81 int unsignedImmediate = insn & 0xffff;
82 int signedImmediate = (insn << 16) >> 16;
83 int branchTarget = signedImmediate;
85 int tmp, addr; // temporaries
94 r[rd] = r[rt] << shamt;
97 r[rd] = r[rt] >>> shamt;
100 r[rd] = r[rt] >> shamt;
103 r[rd] = r[rt] << (r[rs]&0x1f);
106 r[rd] = r[rt] >>> (r[rs]&0x1f);
109 r[rd] = r[rt] >> (r[rs]&0x1f);
112 tmp = r[rs]; pc += 4; nextPC = tmp;
115 tmp = r[rs]; pc += 4; r[rd] = pc+4; nextPC = tmp;
119 r[V0] = syscall(r[V0],r[A0],r[A1],r[A2],r[A3]);
120 if(state != RUNNING) { this.pc = nextPC; break OUTER; }
123 throw new ExecutionException("Break");
137 long hilo = (long)(r[rs]) * ((long)r[rt]);
138 hi = (int) (hilo >>> 32);
143 long hilo = (r[rs] & 0xffffffffL) * (r[rt] & 0xffffffffL);
144 hi = (int) (hilo >>> 32);
153 hi = (int)((r[rs] & 0xffffffffL) % (r[rt] & 0xffffffffL));
154 lo = (int)((r[rs] & 0xffffffffL) / (r[rt] & 0xffffffffL));
157 throw new ExecutionException("ADD (add with oveflow trap) not suported");
158 /*This must trap on overflow
159 r[rd] = r[rs] + r[rt];
162 r[rd] = r[rs] + r[rt];
165 throw new ExecutionException("SUB (sub with oveflow trap) not suported");
166 /*This must trap on overflow
167 r[rd] = r[rs] - r[rt];
170 r[rd] = r[rs] - r[rt];
173 r[rd] = r[rs] & r[rt];
176 r[rd] = r[rs] | r[rt];
179 r[rd] = r[rs] ^ r[rt];
182 r[rd] = ~(r[rs] | r[rt]);
185 r[rd] = r[rs] < r[rt] ? 1 : 0;
188 r[rd] = ((r[rs] & 0xffffffffL) < (r[rt] & 0xffffffffL)) ? 1 : 0;
191 throw new ExecutionException("Illegal instruction 0/" + subcode);
199 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
205 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
211 pc += 4; r[RA] = pc+4; tmp = pc + branchTarget*4; nextPC = tmp;
217 pc += 4; r[RA] = pc+4; tmp = pc + branchTarget*4; nextPC = tmp;
222 throw new ExecutionException("Illegal Instruction");
227 tmp = (pc&0xf0000000) | (jumpTarget << 2);
232 tmp = (pc&0xf0000000) | (jumpTarget << 2);
233 pc+=4; r[RA] = pc+4; nextPC = tmp;
238 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
244 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
250 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
256 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
261 r[rt] = r[rs] + signedImmediate;
264 r[rt] = r[rs] + signedImmediate;
267 r[rt] = r[rs] < signedImmediate ? 1 : 0;
270 r[rt] = (r[rs]&0xffffffffL) < (unsignedImmediate&0xffffffffL) ? 1 : 0;
273 r[rt] = r[rs] & unsignedImmediate;
276 r[rt] = r[rs] | unsignedImmediate;
279 r[rt] = r[rs] ^ unsignedImmediate;
282 r[rt] = unsignedImmediate << 16;
285 throw new ExecutionException("TLB/Exception support not implemented");
287 boolean debug = false;
288 String line = debug ? sourceLine(pc) : "";
289 boolean debugon = debug && (line.indexOf("dtoa.c:51") >= 0 || line.indexOf("dtoa.c:52") >= 0 || line.indexOf("test.c") >= 0);
290 if(rs > 8 && debugon)
291 System.out.println(" FP Op: " + op + "/" + rs + "/" + subcode + " " + line);
292 if(roundingMode() != 0 && rs != 6 /*CTC.1*/ && !((rs==16 || rs==17) && subcode == 36 /* CVT.W.Z */))
293 throw new ExecutionException("Non-cvt.w.z operation attempted with roundingMode != round to nearest");
299 if(fs != 31) throw new ExecutionException("FCR " + fs + " unavailable");
306 if(fs != 31) throw new ExecutionException("FCR " + fs + " unavailable");
309 case 8: // BC1F, BC1T
310 if(((fcsr&0x800000)!=0) == (((insn>>>16)&1)!=0)) {
311 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
318 setFloat(fd,getFloat(fs)+getFloat(ft));
321 setFloat(fd,getFloat(fs)-getFloat(ft));
324 setFloat(fd,getFloat(fs)*getFloat(ft));
327 setFloat(fd,getFloat(fs)/getFloat(ft));
330 setFloat(fd,Math.abs(getFloat(fs)));
336 setFloat(fd,-getFloat(fs));
339 setDouble(fd,getFloat(fs));
342 switch(roundingMode()) {
343 case 0: f[fd] = (int)Math.floor(getFloat(fs)+0.5f); break; // Round to nearest
344 case 1: f[fd] = (int)getFloat(fs); break; // Round towards zero
345 case 2: f[fd] = (int)Math.ceil(getFloat(fs)); break; // Round towards plus infinity
346 case 3: f[fd] = (int)Math.floor(getFloat(fs)); break; // Round towards minus infinity
350 setFC(getFloat(fs) == getFloat(ft));
353 setFC(getFloat(fs) < getFloat(ft));
355 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
362 setDouble(fd,getDouble(fs)+getDouble(ft));
365 if(debugon) System.out.println("f" + fd + " = f" + fs + " (" + getDouble(fs) + ") - f" + ft + " (" + getDouble(ft) + ")");
366 setDouble(fd,getDouble(fs)-getDouble(ft));
369 if(debugon) System.out.println("f" + fd + " = f" + fs + " (" + getDouble(fs) + ") * f" + ft + " (" + getDouble(ft) + ")");
370 setDouble(fd,getDouble(fs)*getDouble(ft));
371 if(debugon) System.out.println("f" + fd + " = " + getDouble(fd));
374 setDouble(fd,getDouble(fs)/getDouble(ft));
377 setDouble(fd,Math.abs(getDouble(fs)));
384 setDouble(fd,-getDouble(fs));
387 setFloat(fd,(float)getDouble(fs));
390 if(debugon) System.out.println("CVT.W.D rm: " + roundingMode() + " f" + fs + ":" + getDouble(fs));
391 switch(roundingMode()) {
392 case 0: f[fd] = (int)Math.floor(getDouble(fs)+0.5); break; // Round to nearest
393 case 1: f[fd] = (int)getDouble(fs); break; // Round towards zero
394 case 2: f[fd] = (int)Math.ceil(getDouble(fs)); break; // Round towards plus infinity
395 case 3: f[fd] = (int)Math.floor(getDouble(fs)); break; // Round towards minus infinity
397 if(debugon) System.out.println("CVT.W.D: f" + fd + ":" + f[fd]);
400 setFC(getDouble(fs) == getDouble(ft));
403 setFC(getDouble(fs) < getDouble(ft));
406 setFC(getDouble(fs) <= getDouble(ft));
408 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
412 case 20: { // Integer
417 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
422 throw new ExecutionException("Invalid Instruction 17/" + rs);
427 throw new ExecutionException("No coprocessor installed");
429 addr = r[rs] + signedImmediate;
431 tmp = readPages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)];
432 } catch(RuntimeException e) {
433 tmp = memRead(addr&~3);
436 case 0: tmp = (tmp>>>24)&0xff; break;
437 case 1: tmp = (tmp>>>16)&0xff; break;
438 case 2: tmp = (tmp>>> 8)&0xff; break;
439 case 3: tmp = (tmp>>> 0)&0xff; break;
441 if((tmp&0x80)!=0) tmp |= 0xffffff00; // sign extend
446 addr = r[rs] + signedImmediate;
448 tmp = readPages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)];
449 } catch(RuntimeException e) {
450 tmp = memRead(addr&~3);
453 case 0: tmp = (tmp>>>16)&0xffff; break;
454 case 2: tmp = (tmp>>> 0)&0xffff; break;
456 if((tmp&0x8000)!=0) tmp |= 0xffff0000; // sign extend
461 addr = r[rs] + signedImmediate;
463 tmp = readPages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)];
464 } catch(RuntimeException e) {
465 tmp = memRead(addr&~3);
468 case 0: r[rt] = (r[rt]&0x00000000)|(tmp<< 0); break;
469 case 1: r[rt] = (r[rt]&0x000000ff)|(tmp<< 8); break;
470 case 2: r[rt] = (r[rt]&0x0000ffff)|(tmp<<16); break;
471 case 3: r[rt] = (r[rt]&0x00ffffff)|(tmp<<24); break;
476 addr = r[rs] + signedImmediate;
478 r[rt] = readPages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)];
479 } catch(RuntimeException e) {
480 r[rt] = memRead(addr);
484 addr = r[rs] + signedImmediate;
486 tmp = readPages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)];
487 } catch(RuntimeException e) {
491 case 0: r[rt] = (tmp>>>24)&0xff; break;
492 case 1: r[rt] = (tmp>>>16)&0xff; break;
493 case 2: r[rt] = (tmp>>> 8)&0xff; break;
494 case 3: r[rt] = (tmp>>> 0)&0xff; break;
499 addr = r[rs] + signedImmediate;
501 tmp = readPages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)];
502 } catch(RuntimeException e) {
503 tmp = memRead(addr&~3);
506 case 0: r[rt] = (tmp>>>16)&0xffff; break;
507 case 2: r[rt] = (tmp>>> 0)&0xffff; break;
512 addr = r[rs] + signedImmediate;
514 tmp = readPages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)];
515 } catch(RuntimeException e) {
516 tmp = memRead(addr&~3);
519 case 0: r[rt] = (r[rt]&0xffffff00)|(tmp>>>24); break;
520 case 1: r[rt] = (r[rt]&0xffff0000)|(tmp>>>16); break;
521 case 2: r[rt] = (r[rt]&0xff000000)|(tmp>>> 8); break;
522 case 3: r[rt] = (r[rt]&0x00000000)|(tmp>>> 0); break;
527 addr = r[rs] + signedImmediate;
529 tmp = readPages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)];
530 } catch(RuntimeException e) {
531 tmp = memRead(addr&~3);
534 case 0: tmp = (tmp&0x00ffffff) | ((r[rt]&0xff)<<24); break;
535 case 1: tmp = (tmp&0xff00ffff) | ((r[rt]&0xff)<<16); break;
536 case 2: tmp = (tmp&0xffff00ff) | ((r[rt]&0xff)<< 8); break;
537 case 3: tmp = (tmp&0xffffff00) | ((r[rt]&0xff)<< 0); break;
540 writePages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
541 } catch(RuntimeException e) {
542 memWrite(addr&~3,tmp);
547 addr = r[rs] + signedImmediate;
549 tmp = readPages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)];
550 } catch(RuntimeException e) {
551 tmp = memRead(addr&~3);
554 case 0: tmp = (tmp&0x0000ffff) | ((r[rt]&0xffff)<<16); break;
555 case 2: tmp = (tmp&0xffff0000) | ((r[rt]&0xffff)<< 0); break;
558 writePages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
559 } catch(RuntimeException e) {
560 memWrite(addr&~3,tmp);
565 addr = r[rs] + signedImmediate;
566 tmp = memRead(addr&~3);
568 case 0: tmp=(tmp&0x00000000)|(r[rt]>>> 0); break;
569 case 1: tmp=(tmp&0xff000000)|(r[rt]>>> 8); break;
570 case 2: tmp=(tmp&0xffff0000)|(r[rt]>>>16); break;
571 case 3: tmp=(tmp&0xffffff00)|(r[rt]>>>24); break;
574 writePages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
575 } catch(RuntimeException e) {
576 memWrite(addr&~3,tmp);
581 addr = r[rs] + signedImmediate;
583 writePages[addr>>>PAGE_SHIFT][(addr>>>2)&(PAGE_WORDS-1)] = r[rt];
584 } catch(RuntimeException e) {
585 memWrite(addr&~3,r[rt]);
589 addr = r[rs] + signedImmediate;
590 tmp = memRead(addr&~3);
592 case 0: tmp=(tmp&0x00ffffff)|(r[rt]<<24); break;
593 case 1: tmp=(tmp&0x0000ffff)|(r[rt]<<16); break;
594 case 2: tmp=(tmp&0x000000ff)|(r[rt]<< 8); break;
595 case 3: tmp=(tmp&0x00000000)|(r[rt]<< 0); break;
597 memWrite(addr&~3,tmp);
601 f[rt] = memRead(r[rs] + signedImmediate);
604 memWrite(r[rs] + signedImmediate,f[rt]);
607 throw new ExecutionException("Invalid Instruction: " + op);
612 } catch(ExecutionException e) {
619 public int lookupSymbol(String name) {
620 ELF.Symbol sym = symtab.getGlobalSymbol(name);
621 return sym == null ? -1 : sym.addr;
624 // Image loading function
625 private void loadImage(SeekableData data) throws IOException {
626 if(state != UNINITIALIZED) throw new IllegalStateException("loadImage called on initialized runtime");
628 ELF elf = new ELF(data);
629 symtab = elf.getSymtab();
631 if(elf.header.type != ELF.ELFHeader.ET_EXEC) throw new IOException("Binary is not an executable");
632 if(elf.header.machine != ELF.ELFHeader.EM_MIPS) throw new IOException("Binary is not for the MIPS I Architecture");
633 if(elf.ident.data != ELF.ELFIdent.ELFDATA2MSB) throw new IOException("Binary is not big endian");
635 entryPoint = elf.header.entry;
637 ELF.Symtab symtab = elf.getSymtab();
638 if(symtab == null) throw new IOException("No symtab in binary (did you strip it?)");
639 ELF.Symbol userInfo = symtab.getGlobalSymbol("user_info");
640 ELF.Symbol gpsym = symtab.getGlobalSymbol("_gp");
642 if(gpsym == null) throw new IOException("NO _gp symbol!");
645 if(userInfo != null) {
646 userInfoBase = userInfo.addr;
647 userInfoSize = userInfo.size;
650 ELF.PHeader[] pheaders = elf.pheaders;
652 for(int i=0;i<pheaders.length;i++) {
653 ELF.PHeader ph = pheaders[i];
654 if(ph.type != ELF.PHeader.PT_LOAD) continue;
655 int memsize = ph.memsz;
656 int filesize = ph.filesz;
657 if(memsize == 0) continue;
658 if(memsize < 0) throw new IOException("pheader size too large");
660 if(addr == 0x0) throw new IOException("pheader vaddr == 0x0");
661 brk = max(addr+memsize,brk);
663 for(int j=0;j<memsize+PAGE_SIZE-1;j+=PAGE_SIZE) {
664 int page = (j+addr) >>> PAGE_SHIFT;
665 if(readPages[page] == null)
666 readPages[page] = new int[PAGE_WORDS];
667 if(ph.writable()) writePages[page] = readPages[page];
670 filesize = filesize & ~3;
671 DataInputStream dis = new DataInputStream(ph.getInputStream());
673 readPages[addr >>> PAGE_SHIFT][(addr >>> 2)&(PAGE_WORDS-1)] = dis.readInt();
676 } while(filesize > 0);
680 brkAddr = (brk+PAGE_SIZE-1)&~(PAGE_SIZE-1);
684 protected void setCPUState(CPUState state) {
685 for(int i=1;i<32;i++) registers[i] = state.r[i];
686 for(int i=0;i<32;i++) fpregs[i] = state.f[i];
687 hi=state.hi; lo=state.lo; fcsr=state.fcsr;
691 protected CPUState getCPUState() {
692 CPUState state = new CPUState();
693 for(int i=1;i<32;i++) state.r[i] = registers[i];
694 for(int i=0;i<32;i++) state.f[i] = fpregs[i];
695 state.hi=hi; state.lo=lo; state.fcsr=fcsr;
700 // This is package private for fork() which does all kinds of ugly things behind the scenes
701 Interpreter() { super(4096,65536,true); }
702 public Interpreter(SeekableData data) throws IOException { this(); loadImage(data); }
703 public Interpreter(String filename) throws IOException {
704 this(new SeekableFile(filename,false));
707 public Interpreter(InputStream is) throws IOException { this(new SeekableInputStream(is)); }
710 // NOTE: This probably requires a jdk > 1.1, however, it is only used for debugging
711 private java.util.HashMap sourceLineCache;
712 public String sourceLine(int pc) {
713 final String addr2line = "mips-unknown-elf-addr2line";
714 String line = (String) (sourceLineCache == null ? null : sourceLineCache.get(new Integer(pc)));
715 if(line != null) return line;
716 if(image==null) return null;
718 Process p = java.lang.Runtime.getRuntime().exec(new String[]{addr2line,"-e",image,toHex(pc)});
719 line = new BufferedReader(new InputStreamReader(p.getInputStream())).readLine();
720 if(line == null) return null;
721 while(line.startsWith("../")) line = line.substring(3);
722 if(sourceLineCache == null) sourceLineCache = new java.util.HashMap();
723 sourceLineCache.put(new Integer(pc),line);
725 } catch(IOException e) {
730 public class DebugShutdownHook implements Runnable {
732 int pc = Interpreter.this.pc;
733 if(getState() == RUNNING)
734 System.err.print("\nCPU Executing " + toHex(pc) + ": " + sourceLine(pc) + "\n");
738 public static void main(String[] argv) throws Exception {
739 String image = argv[0];
740 Interpreter emu = new Interpreter(image);
741 java.lang.Runtime.getRuntime().addShutdownHook(new Thread(emu.new DebugShutdownHook()));
742 int status = emu.run(argv);
743 System.err.println("Exit status: " + status);