1 // Copyright 2003 Brian Alliet
2 // Based on org.xwt.imp.MIPS by Adam Megacz
3 // Portions Copyright 2003 Adam Megacz
5 package org.ibex.nestedvm;
7 import org.ibex.nestedvm.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 {
57 final int PAGE_WORDS = (1<<pageShift)>>2;
66 insn = readPages[pc>>>pageShift][(pc>>>2)&PAGE_WORDS-1];
67 } catch (RuntimeException e) {
68 if(pc == 0xdeadbeef) throw new Error("fell off cpu: r2: " + r[2]);
72 int op = (insn >>> 26) & 0xff; // bits 26-31
73 int rs = (insn >>> 21) & 0x1f; // bits 21-25
74 int rt = (insn >>> 16) & 0x1f; // bits 16-20
75 int ft = (insn >>> 16) & 0x1f;
76 int rd = (insn >>> 11) & 0x1f; // bits 11-15
77 int fs = (insn >>> 11) & 0x1f;
78 int shamt = (insn >>> 6) & 0x1f; // bits 6-10
79 int fd = (insn >>> 6) & 0x1f;
80 int subcode = insn & 0x3f; // bits 0-5
82 int jumpTarget = (insn & 0x03ffffff); // bits 0-25
83 int unsignedImmediate = insn & 0xffff;
84 int signedImmediate = (insn << 16) >> 16;
85 int branchTarget = signedImmediate;
87 int tmp, addr; // temporaries
96 r[rd] = r[rt] << shamt;
99 r[rd] = r[rt] >>> shamt;
102 r[rd] = r[rt] >> shamt;
105 r[rd] = r[rt] << (r[rs]&0x1f);
108 r[rd] = r[rt] >>> (r[rs]&0x1f);
111 r[rd] = r[rt] >> (r[rs]&0x1f);
114 tmp = r[rs]; pc += 4; nextPC = tmp;
117 tmp = r[rs]; pc += 4; r[rd] = pc+4; nextPC = tmp;
121 r[V0] = syscall(r[V0],r[A0],r[A1],r[A2],r[A3]);
122 if(state != RUNNING) { this.pc = nextPC; break OUTER; }
125 throw new ExecutionException("Break");
139 long hilo = (long)(r[rs]) * ((long)r[rt]);
140 hi = (int) (hilo >>> 32);
145 long hilo = (r[rs] & 0xffffffffL) * (r[rt] & 0xffffffffL);
146 hi = (int) (hilo >>> 32);
156 hi = (int)((r[rs] & 0xffffffffL) % (r[rt] & 0xffffffffL));
157 lo = (int)((r[rs] & 0xffffffffL) / (r[rt] & 0xffffffffL));
161 throw new ExecutionException("ADD (add with oveflow trap) not suported");
162 /*This must trap on overflow
163 r[rd] = r[rs] + r[rt];
166 r[rd] = r[rs] + r[rt];
169 throw new ExecutionException("SUB (sub with oveflow trap) not suported");
170 /*This must trap on overflow
171 r[rd] = r[rs] - r[rt];
174 r[rd] = r[rs] - r[rt];
177 r[rd] = r[rs] & r[rt];
180 r[rd] = r[rs] | r[rt];
183 r[rd] = r[rs] ^ r[rt];
186 r[rd] = ~(r[rs] | r[rt]);
189 r[rd] = r[rs] < r[rt] ? 1 : 0;
192 r[rd] = ((r[rs] & 0xffffffffL) < (r[rt] & 0xffffffffL)) ? 1 : 0;
195 throw new ExecutionException("Illegal instruction 0/" + subcode);
203 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
209 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
215 pc += 4; r[RA] = pc+4; tmp = pc + branchTarget*4; nextPC = tmp;
221 pc += 4; r[RA] = pc+4; tmp = pc + branchTarget*4; nextPC = tmp;
226 throw new ExecutionException("Illegal Instruction");
231 tmp = (pc&0xf0000000) | (jumpTarget << 2);
236 tmp = (pc&0xf0000000) | (jumpTarget << 2);
237 pc+=4; r[RA] = pc+4; nextPC = tmp;
242 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
248 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
254 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
260 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
265 r[rt] = r[rs] + signedImmediate;
268 r[rt] = r[rs] + signedImmediate;
271 r[rt] = r[rs] < signedImmediate ? 1 : 0;
274 r[rt] = (r[rs]&0xffffffffL) < (signedImmediate&0xffffffffL) ? 1 : 0;
277 r[rt] = r[rs] & unsignedImmediate;
280 r[rt] = r[rs] | unsignedImmediate;
283 r[rt] = r[rs] ^ unsignedImmediate;
286 r[rt] = unsignedImmediate << 16;
289 throw new ExecutionException("TLB/Exception support not implemented");
291 boolean debug = false;
292 String line = debug ? sourceLine(pc) : "";
293 boolean debugon = debug && (line.indexOf("dtoa.c:51") >= 0 || line.indexOf("dtoa.c:52") >= 0 || line.indexOf("test.c") >= 0);
294 if(rs > 8 && debugon)
295 System.out.println(" FP Op: " + op + "/" + rs + "/" + subcode + " " + line);
296 if(roundingMode() != 0 && rs != 6 /*CTC.1*/ && !((rs==16 || rs==17) && subcode == 36 /* CVT.W.Z */))
297 throw new ExecutionException("Non-cvt.w.z operation attempted with roundingMode != round to nearest");
303 if(fs != 31) throw new ExecutionException("FCR " + fs + " unavailable");
310 if(fs != 31) throw new ExecutionException("FCR " + fs + " unavailable");
313 case 8: // BC1F, BC1T
314 if(((fcsr&0x800000)!=0) == (((insn>>>16)&1)!=0)) {
315 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
322 setFloat(fd,getFloat(fs)+getFloat(ft));
325 setFloat(fd,getFloat(fs)-getFloat(ft));
328 setFloat(fd,getFloat(fs)*getFloat(ft));
331 setFloat(fd,getFloat(fs)/getFloat(ft));
334 setFloat(fd,Math.abs(getFloat(fs)));
340 setFloat(fd,-getFloat(fs));
343 setDouble(fd,getFloat(fs));
346 switch(roundingMode()) {
347 case 0: f[fd] = (int)Math.floor(getFloat(fs)+0.5f); break; // Round to nearest
348 case 1: f[fd] = (int)getFloat(fs); break; // Round towards zero
349 case 2: f[fd] = (int)Math.ceil(getFloat(fs)); break; // Round towards plus infinity
350 case 3: f[fd] = (int)Math.floor(getFloat(fs)); break; // Round towards minus infinity
354 setFC(getFloat(fs) == getFloat(ft));
357 setFC(getFloat(fs) < getFloat(ft));
359 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
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));
373 if(debugon) System.out.println("f" + fd + " = f" + fs + " (" + getDouble(fs) + ") * f" + ft + " (" + getDouble(ft) + ")");
374 setDouble(fd,getDouble(fs)*getDouble(ft));
375 if(debugon) System.out.println("f" + fd + " = " + getDouble(fd));
378 setDouble(fd,getDouble(fs)/getDouble(ft));
381 setDouble(fd,Math.abs(getDouble(fs)));
388 setDouble(fd,-getDouble(fs));
391 setFloat(fd,(float)getDouble(fs));
394 if(debugon) System.out.println("CVT.W.D rm: " + roundingMode() + " f" + fs + ":" + getDouble(fs));
395 switch(roundingMode()) {
396 case 0: f[fd] = (int)Math.floor(getDouble(fs)+0.5); break; // Round to nearest
397 case 1: f[fd] = (int)getDouble(fs); break; // Round towards zero
398 case 2: f[fd] = (int)Math.ceil(getDouble(fs)); break; // Round towards plus infinity
399 case 3: f[fd] = (int)Math.floor(getDouble(fs)); break; // Round towards minus infinity
401 if(debugon) System.out.println("CVT.W.D: f" + fd + ":" + f[fd]);
404 setFC(getDouble(fs) == getDouble(ft));
407 setFC(getDouble(fs) < getDouble(ft));
410 setFC(getDouble(fs) <= getDouble(ft));
412 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
416 case 20: { // Integer
421 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
426 throw new ExecutionException("Invalid Instruction 17/" + rs);
431 throw new ExecutionException("No coprocessor installed");
433 addr = r[rs] + signedImmediate;
435 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
436 } catch(RuntimeException e) {
437 tmp = memRead(addr&~3);
440 case 0: tmp = (tmp>>>24)&0xff; break;
441 case 1: tmp = (tmp>>>16)&0xff; break;
442 case 2: tmp = (tmp>>> 8)&0xff; break;
443 case 3: tmp = (tmp>>> 0)&0xff; break;
445 if((tmp&0x80)!=0) tmp |= 0xffffff00; // sign extend
450 addr = r[rs] + signedImmediate;
452 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
453 } catch(RuntimeException e) {
454 tmp = memRead(addr&~3);
457 case 0: tmp = (tmp>>>16)&0xffff; break;
458 case 2: tmp = (tmp>>> 0)&0xffff; break;
460 if((tmp&0x8000)!=0) tmp |= 0xffff0000; // sign extend
465 addr = r[rs] + signedImmediate;
467 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
468 } catch(RuntimeException e) {
469 tmp = memRead(addr&~3);
472 case 0: r[rt] = (r[rt]&0x00000000)|(tmp<< 0); break;
473 case 1: r[rt] = (r[rt]&0x000000ff)|(tmp<< 8); break;
474 case 2: r[rt] = (r[rt]&0x0000ffff)|(tmp<<16); break;
475 case 3: r[rt] = (r[rt]&0x00ffffff)|(tmp<<24); break;
480 addr = r[rs] + signedImmediate;
482 r[rt] = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
483 } catch(RuntimeException e) {
484 r[rt] = memRead(addr);
488 addr = r[rs] + signedImmediate;
490 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
491 } catch(RuntimeException e) {
495 case 0: r[rt] = (tmp>>>24)&0xff; break;
496 case 1: r[rt] = (tmp>>>16)&0xff; break;
497 case 2: r[rt] = (tmp>>> 8)&0xff; break;
498 case 3: r[rt] = (tmp>>> 0)&0xff; break;
503 addr = r[rs] + signedImmediate;
505 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
506 } catch(RuntimeException e) {
507 tmp = memRead(addr&~3);
510 case 0: r[rt] = (tmp>>>16)&0xffff; break;
511 case 2: r[rt] = (tmp>>> 0)&0xffff; break;
516 addr = r[rs] + signedImmediate;
518 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
519 } catch(RuntimeException e) {
520 tmp = memRead(addr&~3);
523 case 0: r[rt] = (r[rt]&0xffffff00)|(tmp>>>24); break;
524 case 1: r[rt] = (r[rt]&0xffff0000)|(tmp>>>16); break;
525 case 2: r[rt] = (r[rt]&0xff000000)|(tmp>>> 8); break;
526 case 3: r[rt] = (r[rt]&0x00000000)|(tmp>>> 0); break;
531 addr = r[rs] + signedImmediate;
533 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
534 } catch(RuntimeException e) {
535 tmp = memRead(addr&~3);
538 case 0: tmp = (tmp&0x00ffffff) | ((r[rt]&0xff)<<24); break;
539 case 1: tmp = (tmp&0xff00ffff) | ((r[rt]&0xff)<<16); break;
540 case 2: tmp = (tmp&0xffff00ff) | ((r[rt]&0xff)<< 8); break;
541 case 3: tmp = (tmp&0xffffff00) | ((r[rt]&0xff)<< 0); break;
544 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
545 } catch(RuntimeException e) {
546 memWrite(addr&~3,tmp);
551 addr = r[rs] + signedImmediate;
553 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
554 } catch(RuntimeException e) {
555 tmp = memRead(addr&~3);
558 case 0: tmp = (tmp&0x0000ffff) | ((r[rt]&0xffff)<<16); break;
559 case 2: tmp = (tmp&0xffff0000) | ((r[rt]&0xffff)<< 0); break;
562 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
563 } catch(RuntimeException e) {
564 memWrite(addr&~3,tmp);
569 addr = r[rs] + signedImmediate;
570 tmp = memRead(addr&~3);
572 case 0: tmp=(tmp&0x00000000)|(r[rt]>>> 0); break;
573 case 1: tmp=(tmp&0xff000000)|(r[rt]>>> 8); break;
574 case 2: tmp=(tmp&0xffff0000)|(r[rt]>>>16); break;
575 case 3: tmp=(tmp&0xffffff00)|(r[rt]>>>24); break;
578 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
579 } catch(RuntimeException e) {
580 memWrite(addr&~3,tmp);
585 addr = r[rs] + signedImmediate;
587 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = r[rt];
588 } catch(RuntimeException e) {
589 memWrite(addr&~3,r[rt]);
593 addr = r[rs] + signedImmediate;
594 tmp = memRead(addr&~3);
596 case 0: tmp=(tmp&0x00ffffff)|(r[rt]<<24); break;
597 case 1: tmp=(tmp&0x0000ffff)|(r[rt]<<16); break;
598 case 2: tmp=(tmp&0x000000ff)|(r[rt]<< 8); break;
599 case 3: tmp=(tmp&0x00000000)|(r[rt]<< 0); break;
601 memWrite(addr&~3,tmp);
604 // Needs to be atomic w/ threads
606 r[rt] = memRead(r[rs] + signedImmediate);
609 f[rt] = memRead(r[rs] + signedImmediate);
611 // Needs to be atomic w/ threads
613 memWrite(r[rs] + signedImmediate,r[rt]);
617 memWrite(r[rs] + signedImmediate,f[rt]);
620 throw new ExecutionException("Invalid Instruction: " + op);
625 } catch(ExecutionException e) {
632 public int lookupSymbol(String name) {
633 ELF.Symbol sym = symtab.getGlobalSymbol(name);
634 return sym == null ? -1 : sym.addr;
638 protected int gp() { return gp; }
640 private ELF.Symbol userInfo;
641 protected int userInfoBae() { return userInfo == null ? 0 : userInfo.addr; }
642 protected int userInfoSize() { return userInfo == null ? 0 : userInfo.size; }
644 private int entryPoint;
645 protected int entryPoint() { return entryPoint; }
647 private int heapStart;
648 protected int heapStart() { return heapStart; }
650 // Image loading function
651 private void loadImage(Seekable data) throws IOException {
652 ELF elf = new ELF(data);
653 symtab = elf.getSymtab();
655 if(elf.header.type != ELF.ELFHeader.ET_EXEC) throw new IOException("Binary is not an executable");
656 if(elf.header.machine != ELF.ELFHeader.EM_MIPS) throw new IOException("Binary is not for the MIPS I Architecture");
657 if(elf.ident.data != ELF.ELFIdent.ELFDATA2MSB) throw new IOException("Binary is not big endian");
659 entryPoint = elf.header.entry;
661 ELF.Symtab symtab = elf.getSymtab();
662 if(symtab == null) throw new IOException("No symtab in binary (did you strip it?)");
663 userInfo = symtab.getGlobalSymbol("user_info");
664 ELF.Symbol gpsym = symtab.getGlobalSymbol("_gp");
666 if(gpsym == null) throw new IOException("NO _gp symbol!");
669 entryPoint = elf.header.entry;
671 ELF.PHeader[] pheaders = elf.pheaders;
673 int pageSize = (1<<pageShift);
674 int pageWords = (1<<pageShift) >> 2;
675 for(int i=0;i<pheaders.length;i++) {
676 ELF.PHeader ph = pheaders[i];
677 if(ph.type != ELF.PHeader.PT_LOAD) continue;
678 int memsize = ph.memsz;
679 int filesize = ph.filesz;
680 if(memsize == 0) continue;
681 if(memsize < 0) throw new IOException("pheader size too large");
683 if(addr == 0x0) throw new IOException("pheader vaddr == 0x0");
684 brk = max(addr+memsize,brk);
686 for(int j=0;j<memsize+pageSize-1;j+=pageSize) {
687 int page = (j+addr) >>> pageShift;
688 if(readPages[page] == null)
689 readPages[page] = new int[pageWords];
690 if(ph.writable()) writePages[page] = readPages[page];
693 filesize = filesize & ~3;
694 DataInputStream dis = new DataInputStream(ph.getInputStream());
696 readPages[addr >>> pageShift][(addr >>> 2)&(pageWords-1)] = dis.readInt();
699 } while(filesize > 0);
703 heapStart = (brk+pageSize-1)&~(pageSize-1);
706 protected void setCPUState(CPUState state) {
707 for(int i=1;i<32;i++) registers[i] = state.r[i];
708 for(int i=0;i<32;i++) fpregs[i] = state.f[i];
709 hi=state.hi; lo=state.lo; fcsr=state.fcsr;
713 protected void getCPUState(CPUState state) {
714 for(int i=1;i<32;i++) state.r[i] = registers[i];
715 for(int i=0;i<32;i++) state.f[i] = fpregs[i];
716 state.hi=hi; state.lo=lo; state.fcsr=fcsr;
720 public Interpreter(Seekable data) throws IOException {
724 public Interpreter(String filename) throws IOException {
725 this(new Seekable.File(filename,false));
728 public Interpreter(InputStream is) throws IOException { this(new Seekable.InputStream(is)); }
731 // NOTE: This probably requires a jdk > 1.1, however, it is only used for debugging
732 private java.util.HashMap sourceLineCache;
733 public String sourceLine(int pc) {
734 final String addr2line = "mips-unknown-elf-addr2line";
735 String line = (String) (sourceLineCache == null ? null : sourceLineCache.get(new Integer(pc)));
736 if(line != null) return line;
737 if(image==null) return null;
739 Process p = java.lang.Runtime.getRuntime().exec(new String[]{addr2line,"-e",image,toHex(pc)});
740 line = new BufferedReader(new InputStreamReader(p.getInputStream())).readLine();
741 if(line == null) return null;
742 while(line.startsWith("../")) line = line.substring(3);
743 if(sourceLineCache == null) sourceLineCache = new java.util.HashMap();
744 sourceLineCache.put(new Integer(pc),line);
746 } catch(IOException e) {
751 public class DebugShutdownHook implements Runnable {
753 int pc = Interpreter.this.pc;
754 if(getState() == RUNNING)
755 System.err.print("\nCPU Executing " + toHex(pc) + ": " + sourceLine(pc) + "\n");
759 public static void main(String[] argv) throws Exception {
760 String image = argv[0];
761 Interpreter emu = new Interpreter(image);
762 java.lang.Runtime.getRuntime().addShutdownHook(new Thread(emu.new DebugShutdownHook()));
763 int status = emu.run(argv);
764 System.err.println("Exit status: " + status);