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) {
71 int op = (insn >>> 26) & 0xff; // bits 26-31
72 int rs = (insn >>> 21) & 0x1f; // bits 21-25
73 int rt = (insn >>> 16) & 0x1f; // bits 16-20
74 int ft = (insn >>> 16) & 0x1f;
75 int rd = (insn >>> 11) & 0x1f; // bits 11-15
76 int fs = (insn >>> 11) & 0x1f;
77 int shamt = (insn >>> 6) & 0x1f; // bits 6-10
78 int fd = (insn >>> 6) & 0x1f;
79 int subcode = insn & 0x3f; // bits 0-5
81 int jumpTarget = (insn & 0x03ffffff); // bits 0-25
82 int unsignedImmediate = insn & 0xffff;
83 int signedImmediate = (insn << 16) >> 16;
84 int branchTarget = signedImmediate;
86 int tmp, addr; // temporaries
95 r[rd] = r[rt] << shamt;
98 r[rd] = r[rt] >>> shamt;
101 r[rd] = r[rt] >> shamt;
104 r[rd] = r[rt] << (r[rs]&0x1f);
107 r[rd] = r[rt] >>> (r[rs]&0x1f);
110 r[rd] = r[rt] >> (r[rs]&0x1f);
113 tmp = r[rs]; pc += 4; nextPC = tmp;
116 tmp = r[rs]; pc += 4; r[rd] = pc+4; nextPC = tmp;
120 r[V0] = syscall(r[V0],r[A0],r[A1],r[A2],r[A3]);
121 if(state != RUNNING) { this.pc = nextPC; break OUTER; }
124 throw new ExecutionException("Break");
138 long hilo = (long)(r[rs]) * ((long)r[rt]);
139 hi = (int) (hilo >>> 32);
144 long hilo = (r[rs] & 0xffffffffL) * (r[rt] & 0xffffffffL);
145 hi = (int) (hilo >>> 32);
155 hi = (int)((r[rs] & 0xffffffffL) % (r[rt] & 0xffffffffL));
156 lo = (int)((r[rs] & 0xffffffffL) / (r[rt] & 0xffffffffL));
160 throw new ExecutionException("ADD (add with oveflow trap) not suported");
161 /*This must trap on overflow
162 r[rd] = r[rs] + r[rt];
165 r[rd] = r[rs] + r[rt];
168 throw new ExecutionException("SUB (sub with oveflow trap) not suported");
169 /*This must trap on overflow
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]);
188 r[rd] = r[rs] < r[rt] ? 1 : 0;
191 r[rd] = ((r[rs] & 0xffffffffL) < (r[rt] & 0xffffffffL)) ? 1 : 0;
194 throw new ExecutionException("Illegal instruction 0/" + subcode);
202 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
208 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
214 pc += 4; r[RA] = pc+4; tmp = pc + branchTarget*4; nextPC = tmp;
220 pc += 4; r[RA] = pc+4; tmp = pc + branchTarget*4; nextPC = tmp;
225 throw new ExecutionException("Illegal Instruction");
230 tmp = (pc&0xf0000000) | (jumpTarget << 2);
235 tmp = (pc&0xf0000000) | (jumpTarget << 2);
236 pc+=4; r[RA] = pc+4; nextPC = tmp;
241 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
247 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
253 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
259 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
264 r[rt] = r[rs] + signedImmediate;
267 r[rt] = r[rs] + signedImmediate;
270 r[rt] = r[rs] < signedImmediate ? 1 : 0;
273 r[rt] = (r[rs]&0xffffffffL) < (unsignedImmediate&0xffffffffL) ? 1 : 0;
276 r[rt] = r[rs] & unsignedImmediate;
279 r[rt] = r[rs] | unsignedImmediate;
282 r[rt] = r[rs] ^ unsignedImmediate;
285 r[rt] = unsignedImmediate << 16;
288 throw new ExecutionException("TLB/Exception support not implemented");
290 boolean debug = false;
291 String line = debug ? sourceLine(pc) : "";
292 boolean debugon = debug && (line.indexOf("dtoa.c:51") >= 0 || line.indexOf("dtoa.c:52") >= 0 || line.indexOf("test.c") >= 0);
293 if(rs > 8 && debugon)
294 System.out.println(" FP Op: " + op + "/" + rs + "/" + subcode + " " + line);
295 if(roundingMode() != 0 && rs != 6 /*CTC.1*/ && !((rs==16 || rs==17) && subcode == 36 /* CVT.W.Z */))
296 throw new ExecutionException("Non-cvt.w.z operation attempted with roundingMode != round to nearest");
302 if(fs != 31) throw new ExecutionException("FCR " + fs + " unavailable");
309 if(fs != 31) throw new ExecutionException("FCR " + fs + " unavailable");
312 case 8: // BC1F, BC1T
313 if(((fcsr&0x800000)!=0) == (((insn>>>16)&1)!=0)) {
314 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
321 setFloat(fd,getFloat(fs)+getFloat(ft));
324 setFloat(fd,getFloat(fs)-getFloat(ft));
327 setFloat(fd,getFloat(fs)*getFloat(ft));
330 setFloat(fd,getFloat(fs)/getFloat(ft));
333 setFloat(fd,Math.abs(getFloat(fs)));
339 setFloat(fd,-getFloat(fs));
342 setDouble(fd,getFloat(fs));
345 switch(roundingMode()) {
346 case 0: f[fd] = (int)Math.floor(getFloat(fs)+0.5f); break; // Round to nearest
347 case 1: f[fd] = (int)getFloat(fs); break; // Round towards zero
348 case 2: f[fd] = (int)Math.ceil(getFloat(fs)); break; // Round towards plus infinity
349 case 3: f[fd] = (int)Math.floor(getFloat(fs)); break; // Round towards minus infinity
353 setFC(getFloat(fs) == getFloat(ft));
356 setFC(getFloat(fs) < getFloat(ft));
358 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
365 setDouble(fd,getDouble(fs)+getDouble(ft));
368 if(debugon) System.out.println("f" + fd + " = f" + fs + " (" + getDouble(fs) + ") - f" + ft + " (" + getDouble(ft) + ")");
369 setDouble(fd,getDouble(fs)-getDouble(ft));
372 if(debugon) System.out.println("f" + fd + " = f" + fs + " (" + getDouble(fs) + ") * f" + ft + " (" + getDouble(ft) + ")");
373 setDouble(fd,getDouble(fs)*getDouble(ft));
374 if(debugon) System.out.println("f" + fd + " = " + getDouble(fd));
377 setDouble(fd,getDouble(fs)/getDouble(ft));
380 setDouble(fd,Math.abs(getDouble(fs)));
387 setDouble(fd,-getDouble(fs));
390 setFloat(fd,(float)getDouble(fs));
393 if(debugon) System.out.println("CVT.W.D rm: " + roundingMode() + " f" + fs + ":" + getDouble(fs));
394 switch(roundingMode()) {
395 case 0: f[fd] = (int)Math.floor(getDouble(fs)+0.5); break; // Round to nearest
396 case 1: f[fd] = (int)getDouble(fs); break; // Round towards zero
397 case 2: f[fd] = (int)Math.ceil(getDouble(fs)); break; // Round towards plus infinity
398 case 3: f[fd] = (int)Math.floor(getDouble(fs)); break; // Round towards minus infinity
400 if(debugon) System.out.println("CVT.W.D: f" + fd + ":" + f[fd]);
403 setFC(getDouble(fs) == getDouble(ft));
406 setFC(getDouble(fs) < getDouble(ft));
409 setFC(getDouble(fs) <= getDouble(ft));
411 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
415 case 20: { // Integer
420 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
425 throw new ExecutionException("Invalid Instruction 17/" + rs);
430 throw new ExecutionException("No coprocessor installed");
432 addr = r[rs] + signedImmediate;
434 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
435 } catch(RuntimeException e) {
436 tmp = memRead(addr&~3);
439 case 0: tmp = (tmp>>>24)&0xff; break;
440 case 1: tmp = (tmp>>>16)&0xff; break;
441 case 2: tmp = (tmp>>> 8)&0xff; break;
442 case 3: tmp = (tmp>>> 0)&0xff; break;
444 if((tmp&0x80)!=0) tmp |= 0xffffff00; // sign extend
449 addr = r[rs] + signedImmediate;
451 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
452 } catch(RuntimeException e) {
453 tmp = memRead(addr&~3);
456 case 0: tmp = (tmp>>>16)&0xffff; break;
457 case 2: tmp = (tmp>>> 0)&0xffff; break;
459 if((tmp&0x8000)!=0) tmp |= 0xffff0000; // sign extend
464 addr = r[rs] + signedImmediate;
466 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
467 } catch(RuntimeException e) {
468 tmp = memRead(addr&~3);
471 case 0: r[rt] = (r[rt]&0x00000000)|(tmp<< 0); break;
472 case 1: r[rt] = (r[rt]&0x000000ff)|(tmp<< 8); break;
473 case 2: r[rt] = (r[rt]&0x0000ffff)|(tmp<<16); break;
474 case 3: r[rt] = (r[rt]&0x00ffffff)|(tmp<<24); break;
479 addr = r[rs] + signedImmediate;
481 r[rt] = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
482 } catch(RuntimeException e) {
483 r[rt] = memRead(addr);
487 addr = r[rs] + signedImmediate;
489 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
490 } catch(RuntimeException e) {
494 case 0: r[rt] = (tmp>>>24)&0xff; break;
495 case 1: r[rt] = (tmp>>>16)&0xff; break;
496 case 2: r[rt] = (tmp>>> 8)&0xff; break;
497 case 3: r[rt] = (tmp>>> 0)&0xff; break;
502 addr = r[rs] + signedImmediate;
504 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
505 } catch(RuntimeException e) {
506 tmp = memRead(addr&~3);
509 case 0: r[rt] = (tmp>>>16)&0xffff; break;
510 case 2: r[rt] = (tmp>>> 0)&0xffff; break;
515 addr = r[rs] + signedImmediate;
517 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
518 } catch(RuntimeException e) {
519 tmp = memRead(addr&~3);
522 case 0: r[rt] = (r[rt]&0xffffff00)|(tmp>>>24); break;
523 case 1: r[rt] = (r[rt]&0xffff0000)|(tmp>>>16); break;
524 case 2: r[rt] = (r[rt]&0xff000000)|(tmp>>> 8); break;
525 case 3: r[rt] = (r[rt]&0x00000000)|(tmp>>> 0); break;
530 addr = r[rs] + signedImmediate;
532 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
533 } catch(RuntimeException e) {
534 tmp = memRead(addr&~3);
537 case 0: tmp = (tmp&0x00ffffff) | ((r[rt]&0xff)<<24); break;
538 case 1: tmp = (tmp&0xff00ffff) | ((r[rt]&0xff)<<16); break;
539 case 2: tmp = (tmp&0xffff00ff) | ((r[rt]&0xff)<< 8); break;
540 case 3: tmp = (tmp&0xffffff00) | ((r[rt]&0xff)<< 0); break;
543 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
544 } catch(RuntimeException e) {
545 memWrite(addr&~3,tmp);
550 addr = r[rs] + signedImmediate;
552 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
553 } catch(RuntimeException e) {
554 tmp = memRead(addr&~3);
557 case 0: tmp = (tmp&0x0000ffff) | ((r[rt]&0xffff)<<16); break;
558 case 2: tmp = (tmp&0xffff0000) | ((r[rt]&0xffff)<< 0); break;
561 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
562 } catch(RuntimeException e) {
563 memWrite(addr&~3,tmp);
568 addr = r[rs] + signedImmediate;
569 tmp = memRead(addr&~3);
571 case 0: tmp=(tmp&0x00000000)|(r[rt]>>> 0); break;
572 case 1: tmp=(tmp&0xff000000)|(r[rt]>>> 8); break;
573 case 2: tmp=(tmp&0xffff0000)|(r[rt]>>>16); break;
574 case 3: tmp=(tmp&0xffffff00)|(r[rt]>>>24); break;
577 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
578 } catch(RuntimeException e) {
579 memWrite(addr&~3,tmp);
584 addr = r[rs] + signedImmediate;
586 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = r[rt];
587 } catch(RuntimeException e) {
588 memWrite(addr&~3,r[rt]);
592 addr = r[rs] + signedImmediate;
593 tmp = memRead(addr&~3);
595 case 0: tmp=(tmp&0x00ffffff)|(r[rt]<<24); break;
596 case 1: tmp=(tmp&0x0000ffff)|(r[rt]<<16); break;
597 case 2: tmp=(tmp&0x000000ff)|(r[rt]<< 8); break;
598 case 3: tmp=(tmp&0x00000000)|(r[rt]<< 0); break;
600 memWrite(addr&~3,tmp);
603 // Needs to be atomic w/ threads
605 r[rt] = memRead(r[rs] + signedImmediate);
608 f[rt] = memRead(r[rs] + signedImmediate);
610 // Needs to be atomic w/ threads
612 memWrite(r[rs] + signedImmediate,r[rt]);
616 memWrite(r[rs] + signedImmediate,f[rt]);
619 throw new ExecutionException("Invalid Instruction: " + op);
624 } catch(ExecutionException e) {
631 public int lookupSymbol(String name) {
632 ELF.Symbol sym = symtab.getGlobalSymbol(name);
633 return sym == null ? -1 : sym.addr;
637 protected int gp() { return gp; }
639 private ELF.Symbol userInfo;
640 protected int userInfoBae() { return userInfo == null ? 0 : userInfo.addr; }
641 protected int userInfoSize() { return userInfo == null ? 0 : userInfo.size; }
643 private int entryPoint;
644 protected int entryPoint() { return entryPoint; }
646 private int heapStart;
647 protected int heapStart() { return heapStart; }
649 // Image loading function
650 private void loadImage(Seekable data) throws IOException {
651 ELF elf = new ELF(data);
652 symtab = elf.getSymtab();
654 if(elf.header.type != ELF.ELFHeader.ET_EXEC) throw new IOException("Binary is not an executable");
655 if(elf.header.machine != ELF.ELFHeader.EM_MIPS) throw new IOException("Binary is not for the MIPS I Architecture");
656 if(elf.ident.data != ELF.ELFIdent.ELFDATA2MSB) throw new IOException("Binary is not big endian");
658 entryPoint = elf.header.entry;
660 ELF.Symtab symtab = elf.getSymtab();
661 if(symtab == null) throw new IOException("No symtab in binary (did you strip it?)");
662 userInfo = symtab.getGlobalSymbol("user_info");
663 ELF.Symbol gpsym = symtab.getGlobalSymbol("_gp");
665 if(gpsym == null) throw new IOException("NO _gp symbol!");
668 entryPoint = elf.header.entry;
670 ELF.PHeader[] pheaders = elf.pheaders;
672 int pageSize = (1<<pageShift);
673 int pageWords = (1<<pageShift) >> 2;
674 for(int i=0;i<pheaders.length;i++) {
675 ELF.PHeader ph = pheaders[i];
676 if(ph.type != ELF.PHeader.PT_LOAD) continue;
677 int memsize = ph.memsz;
678 int filesize = ph.filesz;
679 if(memsize == 0) continue;
680 if(memsize < 0) throw new IOException("pheader size too large");
682 if(addr == 0x0) throw new IOException("pheader vaddr == 0x0");
683 brk = max(addr+memsize,brk);
685 for(int j=0;j<memsize+pageSize-1;j+=pageSize) {
686 int page = (j+addr) >>> pageShift;
687 if(readPages[page] == null)
688 readPages[page] = new int[pageWords];
689 if(ph.writable()) writePages[page] = readPages[page];
692 filesize = filesize & ~3;
693 DataInputStream dis = new DataInputStream(ph.getInputStream());
695 readPages[addr >>> pageShift][(addr >>> 2)&(pageWords-1)] = dis.readInt();
698 } while(filesize > 0);
702 heapStart = (brk+pageSize-1)&~(pageSize-1);
705 protected void setCPUState(CPUState state) {
706 for(int i=1;i<32;i++) registers[i] = state.r[i];
707 for(int i=0;i<32;i++) fpregs[i] = state.f[i];
708 hi=state.hi; lo=state.lo; fcsr=state.fcsr;
712 protected void getCPUState(CPUState state) {
713 for(int i=1;i<32;i++) state.r[i] = registers[i];
714 for(int i=0;i<32;i++) state.f[i] = fpregs[i];
715 state.hi=hi; state.lo=lo; state.fcsr=fcsr;
719 public Interpreter(Seekable data) throws IOException {
723 public Interpreter(String filename) throws IOException {
724 this(new Seekable.File(filename,false));
727 public Interpreter(InputStream is) throws IOException { this(new Seekable.InputStream(is)); }
730 // NOTE: This probably requires a jdk > 1.1, however, it is only used for debugging
731 private java.util.HashMap sourceLineCache;
732 public String sourceLine(int pc) {
733 final String addr2line = "mips-unknown-elf-addr2line";
734 String line = (String) (sourceLineCache == null ? null : sourceLineCache.get(new Integer(pc)));
735 if(line != null) return line;
736 if(image==null) return null;
738 Process p = java.lang.Runtime.getRuntime().exec(new String[]{addr2line,"-e",image,toHex(pc)});
739 line = new BufferedReader(new InputStreamReader(p.getInputStream())).readLine();
740 if(line == null) return null;
741 while(line.startsWith("../")) line = line.substring(3);
742 if(sourceLineCache == null) sourceLineCache = new java.util.HashMap();
743 sourceLineCache.put(new Integer(pc),line);
745 } catch(IOException e) {
750 public class DebugShutdownHook implements Runnable {
752 int pc = Interpreter.this.pc;
753 if(getState() == RUNNING)
754 System.err.print("\nCPU Executing " + toHex(pc) + ": " + sourceLine(pc) + "\n");
758 public static void main(String[] argv) throws Exception {
759 String image = argv[0];
760 Interpreter emu = new Interpreter(image);
761 java.lang.Runtime.getRuntime().addShutdownHook(new Thread(emu.new DebugShutdownHook()));
762 int status = emu.run(argv);
763 System.err.println("Exit status: " + status);