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 implements Cloneable {
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));
54 protected Object clone() throws CloneNotSupportedException {
55 Interpreter r = (Interpreter) super.clone();
56 r.registers = (int[]) registers.clone();
57 r.fpregs = (int[]) fpregs.clone();
62 // the return value is meaningless, its just to catch people typing "return" by accident
63 private final int runSome() throws FaultException,ExecutionException {
64 final int PAGE_WORDS = (1<<pageShift)>>2;
73 insn = readPages[pc>>>pageShift][(pc>>>2)&PAGE_WORDS-1];
74 } catch (RuntimeException e) {
75 if(pc == 0xdeadbeef) throw new Error("fell off cpu: r2: " + r[2]);
79 int op = (insn >>> 26) & 0xff; // bits 26-31
80 int rs = (insn >>> 21) & 0x1f; // bits 21-25
81 int rt = (insn >>> 16) & 0x1f; // bits 16-20
82 int ft = (insn >>> 16) & 0x1f;
83 int rd = (insn >>> 11) & 0x1f; // bits 11-15
84 int fs = (insn >>> 11) & 0x1f;
85 int shamt = (insn >>> 6) & 0x1f; // bits 6-10
86 int fd = (insn >>> 6) & 0x1f;
87 int subcode = insn & 0x3f; // bits 0-5
89 int jumpTarget = (insn & 0x03ffffff); // bits 0-25
90 int unsignedImmediate = insn & 0xffff;
91 int signedImmediate = (insn << 16) >> 16;
92 int branchTarget = signedImmediate;
94 int tmp, addr; // temporaries
103 r[rd] = r[rt] << shamt;
106 r[rd] = r[rt] >>> shamt;
109 r[rd] = r[rt] >> shamt;
112 r[rd] = r[rt] << (r[rs]&0x1f);
115 r[rd] = r[rt] >>> (r[rs]&0x1f);
118 r[rd] = r[rt] >> (r[rs]&0x1f);
121 tmp = r[rs]; pc += 4; nextPC = tmp;
124 tmp = r[rs]; pc += 4; r[rd] = pc+4; nextPC = tmp;
128 r[V0] = syscall(r[V0],r[A0],r[A1],r[A2],r[A3],r[T0],r[T1]);
129 if(state != RUNNING) { this.pc = nextPC; break OUTER; }
132 throw new ExecutionException("Break");
146 long hilo = ((long)r[rs]) * ((long)r[rt]);
147 hi = (int) (hilo >>> 32);
152 long hilo = (r[rs] & 0xffffffffL) * (r[rt] & 0xffffffffL);
153 hi = (int) (hilo >>> 32);
163 hi = (int)((r[rs] & 0xffffffffL) % (r[rt] & 0xffffffffL));
164 lo = (int)((r[rs] & 0xffffffffL) / (r[rt] & 0xffffffffL));
168 throw new ExecutionException("ADD (add 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 throw new ExecutionException("SUB (sub with oveflow trap) not suported");
177 /*This must trap on overflow
178 r[rd] = r[rs] - r[rt];
181 r[rd] = r[rs] - r[rt];
184 r[rd] = r[rs] & r[rt];
187 r[rd] = r[rs] | r[rt];
190 r[rd] = r[rs] ^ r[rt];
193 r[rd] = ~(r[rs] | r[rt]);
196 r[rd] = r[rs] < r[rt] ? 1 : 0;
199 r[rd] = ((r[rs] & 0xffffffffL) < (r[rt] & 0xffffffffL)) ? 1 : 0;
202 throw new ExecutionException("Illegal instruction 0/" + subcode);
210 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
216 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
222 pc += 4; r[RA] = pc+4; tmp = pc + branchTarget*4; nextPC = tmp;
228 pc += 4; r[RA] = pc+4; tmp = pc + branchTarget*4; nextPC = tmp;
233 throw new ExecutionException("Illegal Instruction");
238 tmp = (pc&0xf0000000) | (jumpTarget << 2);
243 tmp = (pc&0xf0000000) | (jumpTarget << 2);
244 pc+=4; r[RA] = pc+4; nextPC = tmp;
249 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
255 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
261 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
267 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
272 r[rt] = r[rs] + signedImmediate;
275 r[rt] = r[rs] + signedImmediate;
278 r[rt] = r[rs] < signedImmediate ? 1 : 0;
281 r[rt] = (r[rs]&0xffffffffL) < (signedImmediate&0xffffffffL) ? 1 : 0;
284 r[rt] = r[rs] & unsignedImmediate;
287 r[rt] = r[rs] | unsignedImmediate;
290 r[rt] = r[rs] ^ unsignedImmediate;
293 r[rt] = unsignedImmediate << 16;
296 throw new ExecutionException("TLB/Exception support not implemented");
298 boolean debug = false;
299 String line = debug ? sourceLine(pc) : "";
300 boolean debugon = debug && (line.indexOf("dtoa.c:51") >= 0 || line.indexOf("dtoa.c:52") >= 0 || line.indexOf("test.c") >= 0);
301 if(rs > 8 && debugon)
302 System.out.println(" FP Op: " + op + "/" + rs + "/" + subcode + " " + line);
303 if(roundingMode() != 0 && rs != 6 /*CTC.1*/ && !((rs==16 || rs==17) && subcode == 36 /* CVT.W.Z */))
304 throw new ExecutionException("Non-cvt.w.z operation attempted with roundingMode != round to nearest");
310 if(fs != 31) throw new ExecutionException("FCR " + fs + " unavailable");
317 if(fs != 31) throw new ExecutionException("FCR " + fs + " unavailable");
320 case 8: // BC1F, BC1T
321 if(((fcsr&0x800000)!=0) == (((insn>>>16)&1)!=0)) {
322 pc += 4; tmp = pc + branchTarget*4; nextPC = tmp;
329 setFloat(fd,getFloat(fs)+getFloat(ft));
332 setFloat(fd,getFloat(fs)-getFloat(ft));
335 setFloat(fd,getFloat(fs)*getFloat(ft));
338 setFloat(fd,getFloat(fs)/getFloat(ft));
341 setFloat(fd,Math.abs(getFloat(fs)));
347 setFloat(fd,-getFloat(fs));
350 setDouble(fd,getFloat(fs));
353 switch(roundingMode()) {
354 case 0: f[fd] = (int)Math.floor(getFloat(fs)+0.5f); break; // Round to nearest
355 case 1: f[fd] = (int)getFloat(fs); break; // Round towards zero
356 case 2: f[fd] = (int)Math.ceil(getFloat(fs)); break; // Round towards plus infinity
357 case 3: f[fd] = (int)Math.floor(getFloat(fs)); break; // Round towards minus infinity
361 setFC(getFloat(fs) == getFloat(ft));
364 setFC(getFloat(fs) < getFloat(ft));
367 setFC(getFloat(fs) <= getFloat(ft));
369 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
376 setDouble(fd,getDouble(fs)+getDouble(ft));
379 if(debugon) System.out.println("f" + fd + " = f" + fs + " (" + getDouble(fs) + ") - f" + ft + " (" + getDouble(ft) + ")");
380 setDouble(fd,getDouble(fs)-getDouble(ft));
383 if(debugon) System.out.println("f" + fd + " = f" + fs + " (" + getDouble(fs) + ") * f" + ft + " (" + getDouble(ft) + ")");
384 setDouble(fd,getDouble(fs)*getDouble(ft));
385 if(debugon) System.out.println("f" + fd + " = " + getDouble(fd));
388 setDouble(fd,getDouble(fs)/getDouble(ft));
391 setDouble(fd,Math.abs(getDouble(fs)));
398 setDouble(fd,-getDouble(fs));
401 setFloat(fd,(float)getDouble(fs));
404 if(debugon) System.out.println("CVT.W.D rm: " + roundingMode() + " f" + fs + ":" + getDouble(fs));
405 switch(roundingMode()) {
406 case 0: f[fd] = (int)Math.floor(getDouble(fs)+0.5); break; // Round to nearest
407 case 1: f[fd] = (int)getDouble(fs); break; // Round towards zero
408 case 2: f[fd] = (int)Math.ceil(getDouble(fs)); break; // Round towards plus infinity
409 case 3: f[fd] = (int)Math.floor(getDouble(fs)); break; // Round towards minus infinity
411 if(debugon) System.out.println("CVT.W.D: f" + fd + ":" + f[fd]);
414 setFC(getDouble(fs) == getDouble(ft));
417 setFC(getDouble(fs) < getDouble(ft));
420 setFC(getDouble(fs) <= getDouble(ft));
422 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
426 case 20: { // Integer
434 default: throw new ExecutionException("Invalid Instruction 17/" + rs + "/" + subcode + " at " + sourceLine(pc));
439 throw new ExecutionException("Invalid Instruction 17/" + rs);
444 throw new ExecutionException("No coprocessor installed");
446 addr = r[rs] + signedImmediate;
448 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
449 } catch(RuntimeException e) {
450 tmp = memRead(addr&~3);
453 case 0: tmp = (tmp>>>24)&0xff; break;
454 case 1: tmp = (tmp>>>16)&0xff; break;
455 case 2: tmp = (tmp>>> 8)&0xff; break;
456 case 3: tmp = (tmp>>> 0)&0xff; break;
458 if((tmp&0x80)!=0) tmp |= 0xffffff00; // sign extend
463 addr = r[rs] + signedImmediate;
465 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
466 } catch(RuntimeException e) {
467 tmp = memRead(addr&~3);
470 case 0: tmp = (tmp>>>16)&0xffff; break;
471 case 2: tmp = (tmp>>> 0)&0xffff; break;
473 if((tmp&0x8000)!=0) tmp |= 0xffff0000; // sign extend
478 addr = r[rs] + signedImmediate;
480 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
481 } catch(RuntimeException e) {
482 tmp = memRead(addr&~3);
485 case 0: r[rt] = (r[rt]&0x00000000)|(tmp<< 0); break;
486 case 1: r[rt] = (r[rt]&0x000000ff)|(tmp<< 8); break;
487 case 2: r[rt] = (r[rt]&0x0000ffff)|(tmp<<16); break;
488 case 3: r[rt] = (r[rt]&0x00ffffff)|(tmp<<24); break;
493 addr = r[rs] + signedImmediate;
495 r[rt] = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
496 } catch(RuntimeException e) {
497 r[rt] = memRead(addr);
501 addr = r[rs] + signedImmediate;
503 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
504 } catch(RuntimeException e) {
508 case 0: r[rt] = (tmp>>>24)&0xff; break;
509 case 1: r[rt] = (tmp>>>16)&0xff; break;
510 case 2: r[rt] = (tmp>>> 8)&0xff; break;
511 case 3: r[rt] = (tmp>>> 0)&0xff; 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] = (tmp>>>16)&0xffff; break;
524 case 2: r[rt] = (tmp>>> 0)&0xffff; break;
529 addr = r[rs] + signedImmediate;
531 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
532 } catch(RuntimeException e) {
533 tmp = memRead(addr&~3);
536 case 0: r[rt] = (r[rt]&0xffffff00)|(tmp>>>24); break;
537 case 1: r[rt] = (r[rt]&0xffff0000)|(tmp>>>16); break;
538 case 2: r[rt] = (r[rt]&0xff000000)|(tmp>>> 8); break;
539 case 3: r[rt] = (r[rt]&0x00000000)|(tmp>>> 0); break;
544 addr = r[rs] + signedImmediate;
546 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
547 } catch(RuntimeException e) {
548 tmp = memRead(addr&~3);
551 case 0: tmp = (tmp&0x00ffffff) | ((r[rt]&0xff)<<24); break;
552 case 1: tmp = (tmp&0xff00ffff) | ((r[rt]&0xff)<<16); break;
553 case 2: tmp = (tmp&0xffff00ff) | ((r[rt]&0xff)<< 8); break;
554 case 3: tmp = (tmp&0xffffff00) | ((r[rt]&0xff)<< 0); break;
557 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
558 } catch(RuntimeException e) {
559 memWrite(addr&~3,tmp);
564 addr = r[rs] + signedImmediate;
566 tmp = readPages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)];
567 } catch(RuntimeException e) {
568 tmp = memRead(addr&~3);
571 case 0: tmp = (tmp&0x0000ffff) | ((r[rt]&0xffff)<<16); break;
572 case 2: tmp = (tmp&0xffff0000) | ((r[rt]&0xffff)<< 0); break;
575 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
576 } catch(RuntimeException e) {
577 memWrite(addr&~3,tmp);
582 addr = r[rs] + signedImmediate;
583 tmp = memRead(addr&~3);
585 case 0: tmp=(tmp&0x00000000)|(r[rt]>>> 0); break;
586 case 1: tmp=(tmp&0xff000000)|(r[rt]>>> 8); break;
587 case 2: tmp=(tmp&0xffff0000)|(r[rt]>>>16); break;
588 case 3: tmp=(tmp&0xffffff00)|(r[rt]>>>24); break;
591 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = tmp;
592 } catch(RuntimeException e) {
593 memWrite(addr&~3,tmp);
598 addr = r[rs] + signedImmediate;
600 writePages[addr>>>pageShift][(addr>>>2)&(PAGE_WORDS-1)] = r[rt];
601 } catch(RuntimeException e) {
602 memWrite(addr&~3,r[rt]);
606 addr = r[rs] + signedImmediate;
607 tmp = memRead(addr&~3);
609 case 0: tmp=(tmp&0x00ffffff)|(r[rt]<<24); break;
610 case 1: tmp=(tmp&0x0000ffff)|(r[rt]<<16); break;
611 case 2: tmp=(tmp&0x000000ff)|(r[rt]<< 8); break;
612 case 3: tmp=(tmp&0x00000000)|(r[rt]<< 0); break;
614 memWrite(addr&~3,tmp);
617 // Needs to be atomic w/ threads
619 r[rt] = memRead(r[rs] + signedImmediate);
622 f[rt] = memRead(r[rs] + signedImmediate);
624 // Needs to be atomic w/ threads
626 memWrite(r[rs] + signedImmediate,r[rt]);
630 memWrite(r[rs] + signedImmediate,f[rt]);
633 throw new ExecutionException("Invalid Instruction: " + op);
638 } catch(ExecutionException e) {
645 public int lookupSymbol(String name) {
646 ELF.Symbol sym = symtab.getGlobalSymbol(name);
647 return sym == null ? -1 : sym.addr;
651 protected int gp() { return gp; }
653 private ELF.Symbol userInfo;
654 protected int userInfoBae() { return userInfo == null ? 0 : userInfo.addr; }
655 protected int userInfoSize() { return userInfo == null ? 0 : userInfo.size; }
657 private int entryPoint;
658 protected int entryPoint() { return entryPoint; }
660 private int heapStart;
661 protected int heapStart() { return heapStart; }
663 // Image loading function
664 private void loadImage(Seekable data) throws IOException {
665 ELF elf = new ELF(data);
666 symtab = elf.getSymtab();
668 if(elf.header.type != ELF.ELFHeader.ET_EXEC) throw new IOException("Binary is not an executable");
669 if(elf.header.machine != ELF.ELFHeader.EM_MIPS) throw new IOException("Binary is not for the MIPS I Architecture");
670 if(elf.ident.data != ELF.ELFIdent.ELFDATA2MSB) throw new IOException("Binary is not big endian");
672 entryPoint = elf.header.entry;
674 ELF.Symtab symtab = elf.getSymtab();
675 if(symtab == null) throw new IOException("No symtab in binary (did you strip it?)");
676 userInfo = symtab.getGlobalSymbol("user_info");
677 ELF.Symbol gpsym = symtab.getGlobalSymbol("_gp");
679 if(gpsym == null) throw new IOException("NO _gp symbol!");
682 entryPoint = elf.header.entry;
684 ELF.PHeader[] pheaders = elf.pheaders;
686 int pageSize = (1<<pageShift);
687 int pageWords = (1<<pageShift) >> 2;
688 for(int i=0;i<pheaders.length;i++) {
689 ELF.PHeader ph = pheaders[i];
690 if(ph.type != ELF.PHeader.PT_LOAD) continue;
691 int memsize = ph.memsz;
692 int filesize = ph.filesz;
693 if(memsize == 0) continue;
694 if(memsize < 0) throw new IOException("pheader size too large");
696 if(addr == 0x0) throw new IOException("pheader vaddr == 0x0");
697 brk = max(addr+memsize,brk);
699 for(int j=0;j<memsize+pageSize-1;j+=pageSize) {
700 int page = (j+addr) >>> pageShift;
701 if(readPages[page] == null)
702 readPages[page] = new int[pageWords];
703 if(ph.writable()) writePages[page] = readPages[page];
706 filesize = filesize & ~3;
707 DataInputStream dis = new DataInputStream(ph.getInputStream());
709 readPages[addr >>> pageShift][(addr >>> 2)&(pageWords-1)] = dis.readInt();
712 } while(filesize > 0);
716 heapStart = (brk+pageSize-1)&~(pageSize-1);
719 protected void setCPUState(CPUState state) {
720 for(int i=1;i<32;i++) registers[i] = state.r[i];
721 for(int i=0;i<32;i++) fpregs[i] = state.f[i];
722 hi=state.hi; lo=state.lo; fcsr=state.fcsr;
726 protected void getCPUState(CPUState state) {
727 for(int i=1;i<32;i++) state.r[i] = registers[i];
728 for(int i=0;i<32;i++) state.f[i] = fpregs[i];
729 state.hi=hi; state.lo=lo; state.fcsr=fcsr;
733 public Interpreter(Seekable data) throws IOException {
737 public Interpreter(String filename) throws IOException {
738 this(new Seekable.File(filename,false));
741 public Interpreter(InputStream is) throws IOException { this(new Seekable.InputStream(is)); }
744 // NOTE: This probably requires a jdk > 1.1, however, it is only used for debugging
745 private java.util.HashMap sourceLineCache;
746 public String sourceLine(int pc) {
747 final String addr2line = "mips-unknown-elf-addr2line";
748 String line = (String) (sourceLineCache == null ? null : sourceLineCache.get(new Integer(pc)));
749 if(line != null) return line;
750 if(image==null) return null;
752 Process p = java.lang.Runtime.getRuntime().exec(new String[]{addr2line,"-e",image,toHex(pc)});
753 line = new BufferedReader(new InputStreamReader(p.getInputStream())).readLine();
754 if(line == null) return null;
755 while(line.startsWith("../")) line = line.substring(3);
756 if(sourceLineCache == null) sourceLineCache = new java.util.HashMap();
757 sourceLineCache.put(new Integer(pc),line);
759 } catch(IOException e) {
764 public class DebugShutdownHook implements Runnable {
766 int pc = Interpreter.this.pc;
767 if(getState() == RUNNING)
768 System.err.print("\nCPU Executing " + toHex(pc) + ": " + sourceLine(pc) + "\n");
772 public static void main(String[] argv) throws Exception {
773 String image = argv[0];
774 Interpreter emu = new Interpreter(image);
775 java.lang.Runtime.getRuntime().addShutdownHook(new Thread(emu.new DebugShutdownHook()));
776 int status = emu.run(argv);
777 System.err.println("Exit status: " + status);