1 // Copyright 2003 Brian Alliet
2 // Based on org.xwt.imp.MIPS by Adam Megacz
3 // Portions Copyright 2003 Adam Megacz
5 // FEATURE: Add a patch to gcc that enabled -Wall -Werror by default
7 package org.ibex.nestedvm;
9 import org.ibex.nestedvm.util.*;
12 public abstract class Runtime implements UsermodeConstants,Registers,Cloneable {
13 public static final String VERSION = "1.0";
15 /** True to write useful diagnostic information to stderr when things go wrong */
16 final static boolean STDERR_DIAG = true;
18 /** Number of bits to shift to get the page number (1<<<pageShift == pageSize) */
19 protected final int pageShift;
20 /** Bottom of region of memory allocated to the stack */
21 private final int stackBottom;
23 /** Readable main memory pages */
24 protected int[][] readPages;
25 /** Writable main memory pages.
26 If the page is writable writePages[x] == readPages[x]; if not writePages[x] == null. */
27 protected int[][] writePages;
29 /** The address of the end of the heap */
32 /** Number of guard pages to keep between the stack and the heap */
33 private static final int STACK_GUARD_PAGES = 4;
35 /** The last address the executable uses (other than the heap/stack) */
36 protected abstract int heapStart();
38 /** The program's entry point */
39 protected abstract int entryPoint();
41 /** The location of the _user_info block (or 0 is there is none) */
42 protected int userInfoBase() { return 0; }
43 protected int userInfoSize() { return 0; }
45 /** The location of the global pointer */
46 protected abstract int gp();
48 /** When the process started */
49 private long startTime;
51 /** Program is executing instructions */
52 public final static int RUNNING = 0; // Horrible things will happen if this isn't 0
53 /** Text/Data loaded in memory */
54 public final static int STOPPED = 1;
55 /** Prgram has been started but is paused */
56 public final static int PAUSED = 2;
57 /** Program is executing a callJava() method */
58 public final static int CALLJAVA = 3;
59 /** Program has exited (it cannot currently be restarted) */
60 public final static int EXITED = 4;
61 /** Program has executed a successful exec(), a new Runtime needs to be run (used by UnixRuntime) */
62 public final static int EXECED = 5;
64 /** The current state */
65 protected int state = STOPPED;
66 /** @see Runtime#state state */
67 public final int getState() { return state; }
69 /** The exit status if the process (only valid if state==DONE)
71 private int exitStatus;
72 public ExecutionException exitException;
74 /** Table containing all open file descriptors. (Entries are null if the fd is not in use */
75 FD[] fds = new FD[OPEN_MAX]; // package-private for UnixRuntime
76 boolean closeOnExec[] = new boolean[OPEN_MAX];
78 /** Pointer to a SecurityManager for this process */
80 public void setSecurityManager(SecurityManager sm) { this.sm = sm; }
82 /** Pointer to a callback for the call_java syscall */
83 private CallJavaCB callJavaCB;
84 public void setCallJavaCB(CallJavaCB callJavaCB) { this.callJavaCB = callJavaCB; }
86 /** Temporary buffer for read/write operations */
87 private byte[] _byteBuf;
88 /** Max size of temporary buffer
89 @see Runtime#_byteBuf */
90 final static int MAX_CHUNK = 16*1024*1024 - 1024;
92 /** Subclasses should actually execute program in this method. They should continue
93 executing until state != RUNNING. Only syscall() can modify state. It is safe
94 to only check the state attribute after a call to syscall() */
95 protected abstract void _execute() throws ExecutionException;
97 /** Subclasses should return the address of the symbol <i>symbol</i> or -1 it it doesn't exits in this method
98 This method is only required if the call() function is used */
99 protected int lookupSymbol(String symbol) { return -1; }
101 /** Subclasses should populate a CPUState object representing the cpu state */
102 protected abstract void getCPUState(CPUState state);
104 /** Subclasses should set the CPUState to the state held in <i>state</i> */
105 protected abstract void setCPUState(CPUState state);
107 protected Object clone() throws CloneNotSupportedException {
108 Runtime r = (Runtime) super.clone();
111 r.fds = new FD[OPEN_MAX];
112 for(int i=0;i<OPEN_MAX;i++) if(fds[i] != null) r.fds[i] = fds[i].dup();
113 int totalPages = writePages.length;
114 r.readPages = new int[totalPages][];
115 r.writePages = new int[totalPages][];
116 for(int i=0;i<totalPages;i++) {
117 if(readPages[i] == null) continue;
118 if(writePages[i] == null) r.readPages[i] = readPages[i];
119 else r.readPages[i] = r.writePages[i] = (int[])writePages[i].clone();
124 protected Runtime(int pageSize, int totalPages) {
125 if(pageSize <= 0) throw new IllegalArgumentException("pageSize <= 0");
126 if(totalPages <= 0) throw new IllegalArgumentException("totalPages <= 0");
127 if((pageSize&(pageSize-1)) != 0) throw new IllegalArgumentException("pageSize not a power of two");
130 while(pageSize>>>_pageShift != 1) _pageShift++;
131 pageShift = _pageShift;
133 int heapStart = heapStart();
134 int totalMemory = totalPages * pageSize;
135 int stackSize = max(totalMemory/512,ARG_MAX+65536);
138 stackSize = max(stackSize,pageSize);
139 stackSize = (stackSize + pageSize - 1) & ~(pageSize-1);
140 stackPages = stackSize >>> pageShift;
141 heapStart = (heapStart + pageSize - 1) & ~(pageSize-1);
142 if(stackPages + STACK_GUARD_PAGES + (heapStart >>> pageShift) >= totalPages)
143 throw new IllegalArgumentException("total pages too small");
145 if(pageSize < heapStart + stackSize) throw new IllegalArgumentException("total memory too small");
146 heapStart = (heapStart + 4095) & ~4096;
149 stackBottom = totalMemory - stackSize;
152 readPages = new int[totalPages][];
153 writePages = new int[totalPages][];
155 if(totalPages == 1) {
156 readPages[0] = writePages[0] = new int[pageSize>>2];
158 for(int i=(stackBottom >>> pageShift);i<writePages.length;i++) {
159 readPages[i] = writePages[i] = new int[pageSize>>2];
163 InputStream stdin = Boolean.valueOf(getSystemProperty("nestedvm.textstdin")).booleanValue() ? new TextInputStream(System.in) : System.in;
164 addFD(new TerminalFD(stdin));
165 addFD(new TerminalFD(System.out));
166 addFD(new TerminalFD(System.err));
169 /** Copy everything from <i>src</i> to <i>addr</i> initializing uninitialized pages if required.
170 Newly initalized pages will be marked read-only if <i>ro</i> is set */
171 protected final void initPages(int[] src, int addr, boolean ro) {
172 int pageWords = (1<<pageShift)>>>2;
173 int pageMask = (1<<pageShift) - 1;
175 for(int i=0;i<src.length;) {
176 int page = addr >>> pageShift;
177 int start = (addr&pageMask)>>2;
178 int elements = min(pageWords-start,src.length-i);
179 if(readPages[page]==null) {
182 if(writePages[page] == null) writePages[page] = readPages[page];
184 System.arraycopy(src,i,readPages[page],start,elements);
190 /** Initialize <i>words</i> of pages starting at <i>addr</i> to 0 */
191 protected final void clearPages(int addr, int words) {
192 int pageWords = (1<<pageShift)>>>2;
193 int pageMask = (1<<pageShift) - 1;
195 for(int i=0;i<words;) {
196 int page = addr >>> pageShift;
197 int start = (addr&pageMask)>>2;
198 int elements = min(pageWords-start,words-i);
199 if(readPages[page]==null) {
200 readPages[page] = writePages[page] = new int[pageWords];
202 if(writePages[page] == null) writePages[page] = readPages[page];
203 for(int j=start;j<start+elements;j++) writePages[page][j] = 0;
210 /** Copies <i>length</i> bytes from the processes memory space starting at
211 <i>addr</i> INTO a java byte array <i>a</i> */
212 public final void copyin(int addr, byte[] buf, int count) throws ReadFaultException {
213 int pageWords = (1<<pageShift)>>>2;
214 int pageMask = pageWords - 1;
217 if(count == 0) return;
219 int word = memRead(addr&~3);
221 case 1: buf[x++] = (byte)((word>>>16)&0xff); if(--count==0) break;
222 case 2: buf[x++] = (byte)((word>>> 8)&0xff); if(--count==0) break;
223 case 3: buf[x++] = (byte)((word>>> 0)&0xff); if(--count==0) break;
227 if((count&~3) != 0) {
231 int[] page = readPages[a >>> (pageShift-2)];
232 if(page == null) throw new ReadFaultException(a<<2);
233 int index = a&pageMask;
234 int n = min(c,pageWords-index);
235 for(int i=0;i<n;i++,x+=4) {
236 int word = page[index+i];
237 buf[x+0] = (byte)((word>>>24)&0xff); buf[x+1] = (byte)((word>>>16)&0xff);
238 buf[x+2] = (byte)((word>>> 8)&0xff); buf[x+3] = (byte)((word>>> 0)&0xff);
242 addr = a<<2; count &=3;
245 int word = memRead(addr);
247 case 3: buf[x+2] = (byte)((word>>>8)&0xff);
248 case 2: buf[x+1] = (byte)((word>>>16)&0xff);
249 case 1: buf[x+0] = (byte)((word>>>24)&0xff);
254 /** Copies <i>length</i> bytes OUT OF the java array <i>a</i> into the processes memory
255 space at <i>addr</i> */
256 public final void copyout(byte[] buf, int addr, int count) throws FaultException {
257 int pageWords = (1<<pageShift)>>>2;
258 int pageWordMask = pageWords - 1;
261 if(count == 0) return;
263 int word = memRead(addr&~3);
265 case 1: word = (word&0xff00ffff)|((buf[x++]&0xff)<<16); if(--count==0) break;
266 case 2: word = (word&0xffff00ff)|((buf[x++]&0xff)<< 8); if(--count==0) break;
267 case 3: word = (word&0xffffff00)|((buf[x++]&0xff)<< 0); if(--count==0) break;
269 memWrite(addr&~3,word);
273 if((count&~3) != 0) {
277 int[] page = writePages[a >>> (pageShift-2)];
278 if(page == null) throw new WriteFaultException(a<<2);
279 int index = a&pageWordMask;
280 int n = min(c,pageWords-index);
281 for(int i=0;i<n;i++,x+=4)
282 page[index+i] = ((buf[x+0]&0xff)<<24)|((buf[x+1]&0xff)<<16)|((buf[x+2]&0xff)<<8)|((buf[x+3]&0xff)<<0);
285 addr = a<<2; count&=3;
289 int word = memRead(addr);
291 case 1: word = (word&0x00ffffff)|((buf[x+0]&0xff)<<24); break;
292 case 2: word = (word&0x0000ffff)|((buf[x+0]&0xff)<<24)|((buf[x+1]&0xff)<<16); break;
293 case 3: word = (word&0x000000ff)|((buf[x+0]&0xff)<<24)|((buf[x+1]&0xff)<<16)|((buf[x+2]&0xff)<<8); break;
299 public final void memcpy(int dst, int src, int count) throws FaultException {
300 int pageWords = (1<<pageShift)>>>2;
301 int pageWordMask = pageWords - 1;
302 if((dst&3) == 0 && (src&3)==0) {
303 if((count&~3) != 0) {
308 int[] srcPage = readPages[s>>>(pageShift-2)];
309 if(srcPage == null) throw new ReadFaultException(s<<2);
310 int[] dstPage = writePages[d>>>(pageShift-2)];
311 if(dstPage == null) throw new WriteFaultException(d<<2);
312 int srcIndex = s&pageWordMask;
313 int dstIndex = d&pageWordMask;
314 int n = min(c,pageWords-max(srcIndex,dstIndex));
315 System.arraycopy(srcPage,srcIndex,dstPage,dstIndex,n);
316 s += n; d += n; c -= n;
318 src = s<<2; dst = d<<2; count&=3;
321 int word1 = memRead(src);
322 int word2 = memRead(dst);
324 case 1: memWrite(dst,(word1&0xff000000)|(word2&0x00ffffff)); break;
325 case 2: memWrite(dst,(word1&0xffff0000)|(word2&0x0000ffff)); break;
326 case 3: memWrite(dst,(word1&0xffffff00)|(word2&0x000000ff)); break;
331 int n = min(count,MAX_CHUNK);
332 byte[] buf = byteBuf(n);
335 count -= n; src += n; dst += n;
340 public final void memset(int addr, int ch, int count) throws FaultException {
341 int pageWords = (1<<pageShift)>>>2;
342 int pageWordMask = pageWords - 1;
344 int fourBytes = ((ch&0xff)<<24)|((ch&0xff)<<16)|((ch&0xff)<<8)|((ch&0xff)<<0);
346 int word = memRead(addr&~3);
348 case 1: word = (word&0xff00ffff)|((ch&0xff)<<16); if(--count==0) break;
349 case 2: word = (word&0xffff00ff)|((ch&0xff)<< 8); if(--count==0) break;
350 case 3: word = (word&0xffffff00)|((ch&0xff)<< 0); if(--count==0) break;
352 memWrite(addr&~3,word);
355 if((count&~3) != 0) {
359 int[] page = readPages[a>>>(pageShift-2)];
360 if(page == null) throw new WriteFaultException(a<<2);
361 int index = a&pageWordMask;
362 int n = min(c,pageWords-index);
363 /* Arrays.fill(page,index,index+n,fourBytes);*/
364 for(int i=index;i<index+n;i++) page[i] = fourBytes;
367 addr = a<<2; count&=3;
370 int word = memRead(addr);
372 case 1: word = (word&0x00ffffff)|(fourBytes&0xff000000); break;
373 case 2: word = (word&0x0000ffff)|(fourBytes&0xffff0000); break;
374 case 3: word = (word&0x000000ff)|(fourBytes&0xffffff00); break;
380 /** Read a word from the processes memory at <i>addr</i> */
381 public final int memRead(int addr) throws ReadFaultException {
382 if((addr & 3) != 0) throw new ReadFaultException(addr);
383 return unsafeMemRead(addr);
386 protected final int unsafeMemRead(int addr) throws ReadFaultException {
387 int page = addr >>> pageShift;
388 int entry = (addr&(1<<pageShift) - 1)>>2;
390 return readPages[page][entry];
391 } catch(ArrayIndexOutOfBoundsException e) {
392 if(page < 0 || page >= readPages.length) throw new ReadFaultException(addr);
393 throw e; // should never happen
394 } catch(NullPointerException e) {
395 throw new ReadFaultException(addr);
399 /** Writes a word to the processes memory at <i>addr</i> */
400 public final void memWrite(int addr, int value) throws WriteFaultException {
401 if((addr & 3) != 0) throw new WriteFaultException(addr);
402 unsafeMemWrite(addr,value);
405 protected final void unsafeMemWrite(int addr, int value) throws WriteFaultException {
406 int page = addr >>> pageShift;
407 int entry = (addr&(1<<pageShift) - 1)>>2;
409 writePages[page][entry] = value;
410 } catch(ArrayIndexOutOfBoundsException e) {
411 if(page < 0 || page >= writePages.length) throw new WriteFaultException(addr);
412 throw e; // should never happen
413 } catch(NullPointerException e) {
414 throw new WriteFaultException(addr);
418 /** Created a new non-empty writable page at page number <i>page</i> */
419 private final int[] initPage(int page) { return initPage(page,false); }
420 /** Created a new non-empty page at page number <i>page</i>. If <i>ro</i> is set the page will be read-only */
421 private final int[] initPage(int page, boolean ro) {
422 int[] buf = new int[(1<<pageShift)>>>2];
423 writePages[page] = ro ? null : buf;
424 readPages[page] = buf;
428 /** Returns the exit status of the process. (only valid if state == DONE)
429 @see Runtime#state */
430 public final int exitStatus() {
431 if(state != EXITED) throw new IllegalStateException("exitStatus() called in an inappropriate state");
435 private int addStringArray(String[] strings, int topAddr) throws FaultException {
436 int count = strings.length;
437 int total = 0; /* null last table entry */
438 for(int i=0;i<count;i++) total += strings[i].length() + 1;
439 total += (count+1)*4;
440 int start = (topAddr - total)&~3;
441 int addr = start + (count+1)*4;
442 int[] table = new int[count+1];
444 for(int i=0;i<count;i++) {
445 byte[] a = getBytes(strings[i]);
447 copyout(a,addr,a.length);
448 memset(addr+a.length,0,1);
449 addr += a.length + 1;
452 for(int i=0;i<count+1;i++) {
453 memWrite(addr,table[i]);
456 } catch(FaultException e) {
457 throw new RuntimeException(e.toString());
462 String[] createEnv(String[] extra) { if(extra == null) extra = new String[0]; return extra; }
464 /** Sets word number <i>index</i> in the _user_info table to <i>word</i>
465 * The user_info table is a chunk of memory in the program's memory defined by the
466 * symbol "user_info". The compiler/interpreter automatically determine the size
467 * and location of the user_info table from the ELF symbol table. setUserInfo and
468 * getUserInfo are used to modify the words in the user_info table. */
469 public void setUserInfo(int index, int word) {
470 if(index < 0 || index >= userInfoSize()/4) throw new IndexOutOfBoundsException("setUserInfo called with index >= " + (userInfoSize()/4));
472 memWrite(userInfoBase()+index*4,word);
473 } catch(FaultException e) { throw new RuntimeException(e.toString()); }
476 /** Returns the word in the _user_info table entry <i>index</i>
477 @see Runtime#setUserInfo(int,int) setUserInfo */
478 public int getUserInfo(int index) {
479 if(index < 0 || index >= userInfoSize()/4) throw new IndexOutOfBoundsException("setUserInfo called with index >= " + (userInfoSize()/4));
481 return memRead(userInfoBase()+index*4);
482 } catch(FaultException e) { throw new RuntimeException(e.toString()); }
485 /** Calls _execute() (subclass's execute()) and catches exceptions */
486 // FEATURE: Have these call kill() so we get a pretty message to stdout
487 private void __execute() {
490 } catch(FaultException e) {
491 if(STDERR_DIAG) e.printStackTrace();
492 sys_exit(128+11); // SIGSEGV
494 } catch(ExecutionException e) {
495 if(STDERR_DIAG) e.printStackTrace();
496 sys_exit(128+4); // SIGILL
501 /** Executes the process until the PAUSE syscall is invoked or the process exits. Returns true if the process exited. */
502 public final boolean execute() {
503 if(state != PAUSED) throw new IllegalStateException("execute() called in inappropriate state");
504 if(startTime == 0) startTime = System.currentTimeMillis();
507 if(state != PAUSED && state != EXITED && state != EXECED)
508 throw new IllegalStateException("execute() ended up in an inappropriate state (" + state + ")");
509 return state != PAUSED;
512 static String[] concatArgv(String argv0, String[] rest) {
513 String[] argv = new String[rest.length+1];
514 System.arraycopy(rest,0,argv,1,rest.length);
519 public final int run() { return run(null); }
520 public final int run(String argv0, String[] rest) { return run(concatArgv(argv0,rest)); }
521 public final int run(String[] args) { return run(args,null); }
523 /** Runs the process until it exits and returns the exit status.
524 If the process executes the PAUSE syscall execution will be paused for 500ms and a warning will be displayed */
525 public final int run(String[] args, String[] env) {
529 if(STDERR_DIAG) System.err.println("WARNING: Pause requested while executing run()");
531 if(state == EXECED && STDERR_DIAG) System.err.println("WARNING: Process exec()ed while being run under run()");
532 return state == EXITED ? exitStatus() : 0;
535 public final void start() { start(null); }
536 public final void start(String[] args) { start(args,null); }
538 /** Initializes the process and prepairs it to be executed with execute() */
539 public final void start(String[] args, String[] environ) {
540 int top, sp, argsAddr, envAddr;
541 if(state != STOPPED) throw new IllegalStateException("start() called in inappropriate state");
543 if(args == null) args = new String[]{getClass().getName()};
545 sp = top = writePages.length*(1<<pageShift);
547 sp = argsAddr = addStringArray(args,sp);
548 sp = envAddr = addStringArray(createEnv(environ),sp);
549 } catch(FaultException e) {
550 throw new IllegalArgumentException("args/environ too big");
553 if(top - sp > ARG_MAX) throw new IllegalArgumentException("args/environ too big");
555 // HACK: heapStart() isn't always available when the constructor
556 // is run and this sometimes doesn't get initialized
558 heapEnd = heapStart();
559 if(heapEnd == 0) throw new Error("heapEnd == 0");
560 int pageSize = writePages.length == 1 ? 4096 : (1<<pageShift);
561 heapEnd = (heapEnd + pageSize - 1) & ~(pageSize-1);
564 CPUState cpuState = new CPUState();
565 cpuState.r[A0] = argsAddr;
566 cpuState.r[A1] = envAddr;
568 cpuState.r[RA] = 0xdeadbeef;
569 cpuState.r[GP] = gp();
570 cpuState.pc = entryPoint();
571 setCPUState(cpuState);
578 /** Hook for subclasses to do their own startup */
581 public final int call(String sym, Object[] args) throws CallException, FaultException {
582 if(state != PAUSED && state != CALLJAVA) throw new IllegalStateException("call() called in inappropriate state");
583 if(args.length > 7) throw new IllegalArgumentException("args.length > 7");
584 CPUState state = new CPUState();
587 int sp = state.r[SP];
588 int[] ia = new int[args.length];
589 for(int i=0;i<args.length;i++) {
592 if(o instanceof String) {
593 buf = getBytes((String)o);
594 } else if(o instanceof byte[]) {
596 } else if(o instanceof Number) {
597 ia[i] = ((Number)o).intValue();
601 copyout(buf,sp,buf.length);
605 int oldSP = state.r[SP];
606 if(oldSP == sp) return call(sym,ia);
610 int ret = call(sym,ia);
616 public final int call(String sym) throws CallException { return call(sym,new int[]{}); }
617 public final int call(String sym, int a0) throws CallException { return call(sym,new int[]{a0}); }
618 public final int call(String sym, int a0, int a1) throws CallException { return call(sym,new int[]{a0,a1}); }
620 /** Calls a function in the process with the given arguments */
621 public final int call(String sym, int[] args) throws CallException {
622 int func = lookupSymbol(sym);
623 if(func == -1) throw new CallException(sym + " not found");
624 int helper = lookupSymbol("_call_helper");
625 if(helper == -1) throw new CallException("_call_helper not found");
626 return call(helper,func,args);
629 /** Executes the code at <i>addr</i> in the process setting A0-A3 and S0-S3 to the given arguments
630 and returns the contents of V1 when the the pause syscall is invoked */
631 //public final int call(int addr, int a0, int a1, int a2, int a3, int s0, int s1, int s2, int s3) {
632 public final int call(int addr, int a0, int[] rest) throws CallException {
633 if(rest.length > 7) throw new IllegalArgumentException("rest.length > 7");
634 if(state != PAUSED && state != CALLJAVA) throw new IllegalStateException("call() called in inappropriate state");
635 int oldState = state;
636 CPUState saved = new CPUState();
638 CPUState cpustate = saved.dup();
640 cpustate.r[SP] = cpustate.r[SP]&~15;
641 cpustate.r[RA] = 0xdeadbeef;
643 switch(rest.length) {
644 case 7: cpustate.r[S3] = rest[6];
645 case 6: cpustate.r[S2] = rest[5];
646 case 5: cpustate.r[S1] = rest[4];
647 case 4: cpustate.r[S0] = rest[3];
648 case 3: cpustate.r[A3] = rest[2];
649 case 2: cpustate.r[A2] = rest[1];
650 case 1: cpustate.r[A1] = rest[0];
656 setCPUState(cpustate);
658 getCPUState(cpustate);
661 if(state != PAUSED) throw new CallException("Process exit()ed while servicing a call() request");
664 return cpustate.r[V1];
667 /** Allocated an entry in the FileDescriptor table for <i>fd</i> and returns the number.
668 Returns -1 if the table is full. This can be used by subclasses to use custom file
670 public final int addFD(FD fd) {
671 if(state == EXITED || state == EXECED) throw new IllegalStateException("addFD called in inappropriate state");
673 for(i=0;i<OPEN_MAX;i++) if(fds[i] == null) break;
674 if(i==OPEN_MAX) return -1;
676 closeOnExec[i] = false;
680 /** Closes file descriptor <i>fdn</i> and removes it from the file descriptor table */
681 public final boolean closeFD(int fdn) {
682 if(state == EXITED || state == EXECED) throw new IllegalStateException("closeFD called in inappropriate state");
683 if(fdn < 0 || fdn >= OPEN_MAX) return false;
684 if(fds[fdn] == null) return false;
690 /** Duplicates the file descriptor <i>fdn</i> and returns the new fs */
691 public final int dupFD(int fdn) {
693 if(fdn < 0 || fdn >= OPEN_MAX) return -1;
694 if(fds[fdn] == null) return -1;
695 for(i=0;i<OPEN_MAX;i++) if(fds[i] == null) break;
696 if(i==OPEN_MAX) return -1;
697 fds[i] = fds[fdn].dup();
701 public static final int RD_ONLY = 0;
702 public static final int WR_ONLY = 1;
703 public static final int RDWR = 2;
705 public static final int O_CREAT = 0x0200;
706 public static final int O_EXCL = 0x0800;
707 public static final int O_APPEND = 0x0008;
708 public static final int O_TRUNC = 0x0400;
709 public static final int O_NONBLOCK = 0x4000;
710 public static final int O_NOCTTY = 0x8000;
713 FD hostFSOpen(final File f, int flags, int mode, final Object data) throws ErrnoException {
714 if((flags & ~(3|O_CREAT|O_EXCL|O_APPEND|O_TRUNC)) != 0) {
716 System.err.println("WARNING: Unsupported flags passed to open(\"" + f + "\"): " + toHex(flags & ~(3|O_CREAT|O_EXCL|O_APPEND|O_TRUNC)));
718 throw new ErrnoException(ENOTSUP);
720 boolean write = (flags&3) != RD_ONLY;
722 if(sm != null && !(write ? sm.allowWrite(f) : sm.allowRead(f))) throw new ErrnoException(EACCES);
724 if((flags & (O_EXCL|O_CREAT)) == (O_EXCL|O_CREAT)) {
726 if(Platform.atomicCreateFile(f)) throw new ErrnoException(EEXIST);
727 } catch(IOException e) {
728 throw new ErrnoException(EIO);
730 } else if(!f.exists()) {
731 if((flags&O_CREAT)==0) return null;
732 } else if(f.isDirectory()) {
733 return hostFSDirFD(f,data);
736 final Seekable.File sf;
738 sf = new Seekable.File(f,write,(flags & O_TRUNC) != 0);
739 } catch(FileNotFoundException e) {
740 if(e.getMessage() != null && e.getMessage().indexOf("Permission denied") >= 0) throw new ErrnoException(EACCES);
742 } catch(IOException e) { throw new ErrnoException(EIO); }
744 return new SeekableFD(sf,flags) { protected FStat _fstat() { return hostFStat(f,data); } };
747 FStat hostFStat(File f, Object data) { return new HostFStat(f); }
749 FD hostFSDirFD(File f, Object data) { return null; }
751 FD _open(String path, int flags, int mode) throws ErrnoException {
752 return hostFSOpen(new File(path),flags,mode,null);
755 /** The open syscall */
756 private int sys_open(int addr, int flags, int mode) throws ErrnoException, FaultException {
757 String name = cstring(addr);
759 // HACK: TeX, or GPC, or something really sucks
760 if(name.length() == 1024 && getClass().getName().equals("tests.TeX")) name = name.trim();
762 flags &= ~O_NOCTTY; // this is meaningless under nestedvm
763 FD fd = _open(name,flags,mode);
764 if(fd == null) return -ENOENT;
766 if(fdn == -1) { fd.close(); return -ENFILE; }
770 /** The write syscall */
772 private int sys_write(int fdn, int addr, int count) throws FaultException, ErrnoException {
773 count = Math.min(count,MAX_CHUNK);
774 if(fdn < 0 || fdn >= OPEN_MAX) return -EBADFD;
775 if(fds[fdn] == null) return -EBADFD;
776 byte[] buf = byteBuf(count);
777 copyin(addr,buf,count);
779 return fds[fdn].write(buf,0,count);
780 } catch(ErrnoException e) {
781 if(e.errno == EPIPE) sys_exit(128+13);
786 /** The read syscall */
787 private int sys_read(int fdn, int addr, int count) throws FaultException, ErrnoException {
788 count = Math.min(count,MAX_CHUNK);
789 if(fdn < 0 || fdn >= OPEN_MAX) return -EBADFD;
790 if(fds[fdn] == null) return -EBADFD;
791 byte[] buf = byteBuf(count);
792 int n = fds[fdn].read(buf,0,count);
797 /** The close syscall */
798 private int sys_close(int fdn) {
799 return closeFD(fdn) ? 0 : -EBADFD;
803 /** The seek syscall */
804 private int sys_lseek(int fdn, int offset, int whence) throws ErrnoException {
805 if(fdn < 0 || fdn >= OPEN_MAX) return -EBADFD;
806 if(fds[fdn] == null) return -EBADFD;
807 if(whence != SEEK_SET && whence != SEEK_CUR && whence != SEEK_END) return -EINVAL;
808 int n = fds[fdn].seek(offset,whence);
809 return n < 0 ? -ESPIPE : n;
812 /** The stat/fstat syscall helper */
813 int stat(FStat fs, int addr) throws FaultException {
814 memWrite(addr+0,(fs.dev()<<16)|(fs.inode()&0xffff)); // st_dev (top 16), // st_ino (bottom 16)
815 memWrite(addr+4,((fs.type()&0xf000))|(fs.mode()&0xfff)); // st_mode
816 memWrite(addr+8,fs.nlink()<<16|fs.uid()&0xffff); // st_nlink (top 16) // st_uid (bottom 16)
817 memWrite(addr+12,fs.gid()<<16|0); // st_gid (top 16) // st_rdev (bottom 16)
818 memWrite(addr+16,fs.size()); // st_size
819 memWrite(addr+20,fs.atime()); // st_atime
820 // memWrite(addr+24,0) // st_spare1
821 memWrite(addr+28,fs.mtime()); // st_mtime
822 // memWrite(addr+32,0) // st_spare2
823 memWrite(addr+36,fs.ctime()); // st_ctime
824 // memWrite(addr+40,0) // st_spare3
825 memWrite(addr+44,fs.blksize()); // st_bklsize;
826 memWrite(addr+48,fs.blocks()); // st_blocks
827 // memWrite(addr+52,0) // st_spare4[0]
828 // memWrite(addr+56,0) // st_spare4[1]
832 /** The fstat syscall */
833 private int sys_fstat(int fdn, int addr) throws FaultException {
834 if(fdn < 0 || fdn >= OPEN_MAX) return -EBADFD;
835 if(fds[fdn] == null) return -EBADFD;
836 return stat(fds[fdn].fstat(),addr);
845 private int sys_gettimeofday(int timevalAddr, int timezoneAddr) throws FaultException {
846 long now = System.currentTimeMillis();
847 int tv_sec = (int)(now / 1000);
848 int tv_usec = (int)((now%1000)*1000);
849 memWrite(timevalAddr+0,tv_sec);
850 memWrite(timevalAddr+4,tv_usec);
854 private int sys_sleep(int sec) {
855 if(sec < 0) sec = Integer.MAX_VALUE;
857 Thread.sleep((long)sec*1000);
859 } catch(InterruptedException e) {
865 #define _CLOCKS_PER_SEC_ 1000
866 #define _CLOCK_T_ unsigned long
874 private int sys_times(int tms) {
875 long now = System.currentTimeMillis();
876 int userTime = (int)((now - startTime)/16);
877 int sysTime = (int)((now - startTime)/16);
881 memWrite(tms+0,userTime);
882 memWrite(tms+4,sysTime);
883 memWrite(tms+8,userTime);
884 memWrite(tms+12,sysTime);
886 } catch(FaultException e) {
892 private int sys_sysconf(int n) {
894 case _SC_CLK_TCK: return 1000;
895 case _SC_PAGESIZE: return writePages.length == 1 ? 4096 : (1<<pageShift);
896 case _SC_PHYS_PAGES: return writePages.length == 1 ? (1<<pageShift)/4096 : writePages.length;
898 if(STDERR_DIAG) System.err.println("WARNING: Attempted to use unknown sysconf key: " + n);
903 /** The sbrk syscall. This can also be used by subclasses to allocate memory.
904 <i>incr</i> is how much to increase the break by */
905 public final int sbrk(int incr) {
906 if(incr < 0) return -ENOMEM;
907 if(incr==0) return heapEnd;
909 int oldEnd = heapEnd;
910 int newEnd = oldEnd + incr;
911 if(newEnd >= stackBottom) return -ENOMEM;
913 if(writePages.length > 1) {
914 int pageMask = (1<<pageShift) - 1;
915 int pageWords = (1<<pageShift) >>> 2;
916 int start = (oldEnd + pageMask) >>> pageShift;
917 int end = (newEnd + pageMask) >>> pageShift;
919 for(int i=start;i<end;i++) readPages[i] = writePages[i] = new int[pageWords];
920 } catch(OutOfMemoryError e) {
921 if(STDERR_DIAG) System.err.println("WARNING: Caught OOM Exception in sbrk: " + e);
929 /** The getpid syscall */
930 private int sys_getpid() { return getPid(); }
931 int getPid() { return 1; }
933 public static interface CallJavaCB { public int call(int a, int b, int c, int d); }
935 private int sys_calljava(int a, int b, int c, int d) {
936 if(state != RUNNING) throw new IllegalStateException("wound up calling sys_calljava while not in RUNNING");
937 if(callJavaCB != null) {
941 ret = callJavaCB.call(a,b,c,d);
942 } catch(RuntimeException e) {
943 System.err.println("Error while executing callJavaCB");
950 if(STDERR_DIAG) System.err.println("WARNING: calljava syscall invoked without a calljava callback set");
955 private int sys_pause() {
960 private int sys_getpagesize() { return writePages.length == 1 ? 4096 : (1<<pageShift); }
962 /** Hook for subclasses to do something when the process exits */
965 private int sys_exit(int status) {
967 for(int i=0;i<fds.length;i++) if(fds[i] != null) closeFD(i);
973 private int sys_fcntl(int fdn, int cmd, int arg) {
976 if(fdn < 0 || fdn >= OPEN_MAX) return -EBADFD;
977 if(fds[fdn] == null) return -EBADFD;
982 if(arg < 0 || arg >= OPEN_MAX) return -EINVAL;
983 for(i=arg;i<OPEN_MAX;i++) if(fds[i]==null) break;
984 if(i==OPEN_MAX) return -EMFILE;
990 closeOnExec[fdn] = arg != 0;
993 return closeOnExec[fdn] ? 1 : 0;
995 if(STDERR_DIAG) System.err.println("WARNING: Unknown fcntl command: " + cmd);
1000 /** The syscall dispatcher.
1001 The should be called by subclasses when the syscall instruction is invoked.
1002 <i>syscall</i> should be the contents of V0 and <i>a</i>, <i>b</i>, <i>c</i>, and <i>d</i> should be
1003 the contenst of A0, A1, A2, and A3. The call MAY change the state
1004 @see Runtime#state state */
1005 protected final int syscall(int syscall, int a, int b, int c, int d, int e, int f) {
1007 int n = _syscall(syscall,a,b,c,d,e,f);
1008 //if(n < 0) System.err.println("syscall: " + syscall + " returned " + n);
1010 } catch(ErrnoException ex) {
1011 //ex.printStackTrace();
1013 } catch(FaultException ex) {
1015 } catch(RuntimeException ex) {
1016 ex.printStackTrace();
1017 throw new Error("Internal Error in _syscall()");
1021 int _syscall(int syscall, int a, int b, int c, int d, int e, int f) throws ErrnoException, FaultException {
1023 case SYS_null: return 0;
1024 case SYS_exit: return sys_exit(a);
1025 case SYS_pause: return sys_pause();
1026 case SYS_write: return sys_write(a,b,c);
1027 case SYS_fstat: return sys_fstat(a,b);
1028 case SYS_sbrk: return sbrk(a);
1029 case SYS_open: return sys_open(a,b,c);
1030 case SYS_close: return sys_close(a);
1031 case SYS_read: return sys_read(a,b,c);
1032 case SYS_lseek: return sys_lseek(a,b,c);
1033 case SYS_getpid: return sys_getpid();
1034 case SYS_calljava: return sys_calljava(a,b,c,d);
1035 case SYS_gettimeofday: return sys_gettimeofday(a,b);
1036 case SYS_sleep: return sys_sleep(a);
1037 case SYS_times: return sys_times(a);
1038 case SYS_getpagesize: return sys_getpagesize();
1039 case SYS_fcntl: return sys_fcntl(a,b,c);
1040 case SYS_sysconf: return sys_sysconf(a);
1042 case SYS_memcpy: memcpy(a,b,c); return a;
1043 case SYS_memset: memset(a,b,c); return a;
1054 if(STDERR_DIAG) System.err.println("Attempted to use a UnixRuntime syscall in Runtime (" + syscall + ")");
1057 if(STDERR_DIAG) System.err.println("Attempted to use unknown syscall: " + syscall);
1062 public int xmalloc(int size) { int p=malloc(size); if(p==0) throw new RuntimeException("malloc() failed"); return p; }
1063 public int xrealloc(int addr,int newsize) { int p=realloc(addr,newsize); if(p==0) throw new RuntimeException("realloc() failed"); return p; }
1064 public int realloc(int addr, int newsize) { try { return call("realloc",addr,newsize); } catch(CallException e) { return 0; } }
1065 public int malloc(int size) { try { return call("malloc",size); } catch(CallException e) { return 0; } }
1066 public void free(int p) { try { if(p!=0) call("free",p); } catch(CallException e) { /*noop*/ } }
1068 /** Helper function to create a cstring in main memory */
1069 public int strdup(String s) {
1071 if(s == null) s = "(null)";
1072 byte[] a2 = getBytes(s);
1073 a = new byte[a2.length+1];
1074 System.arraycopy(a2,0,a,0,a2.length);
1075 int addr = malloc(a.length);
1076 if(addr == 0) return 0;
1078 copyout(a,addr,a.length);
1079 } catch(FaultException e) {
1086 /** Helper function to read a cstring from main memory */
1087 public final String cstring(int addr) throws ReadFaultException {
1088 StringBuffer sb = new StringBuffer();
1090 int word = memRead(addr&~3);
1092 case 0: if(((word>>>24)&0xff)==0) return sb.toString(); sb.append((char)((word>>>24)&0xff)); addr++;
1093 case 1: if(((word>>>16)&0xff)==0) return sb.toString(); sb.append((char)((word>>>16)&0xff)); addr++;
1094 case 2: if(((word>>> 8)&0xff)==0) return sb.toString(); sb.append((char)((word>>> 8)&0xff)); addr++;
1095 case 3: if(((word>>> 0)&0xff)==0) return sb.toString(); sb.append((char)((word>>> 0)&0xff)); addr++;
1100 /** File Descriptor class */
1101 public static abstract class FD {
1102 private int refCount = 1;
1104 /** Read some bytes. Should return the number of bytes read, 0 on EOF, or throw an IOException on error */
1105 public int read(byte[] a, int off, int length) throws ErrnoException { throw new ErrnoException(EBADFD); }
1106 /** Write. Should return the number of bytes written or throw an IOException on error */
1107 public int write(byte[] a, int off, int length) throws ErrnoException { throw new ErrnoException(EBADFD); }
1109 /** Seek in the filedescriptor. Whence is SEEK_SET, SEEK_CUR, or SEEK_END. Should return -1 on error or the new position. */
1110 public int seek(int n, int whence) throws ErrnoException { return -1; }
1112 public int getdents(byte[] a, int off, int length) throws ErrnoException { throw new ErrnoException(EBADFD); }
1114 public int flags() { return O_RDONLY; }
1116 /** Return a Seekable object representing this file descriptor (can be read only)
1117 This is required for exec() */
1118 Seekable seekable() { return null; }
1120 private FStat cachedFStat = null;
1121 public final FStat fstat() {
1122 if(cachedFStat == null) cachedFStat = _fstat();
1126 protected abstract FStat _fstat();
1128 /** Closes the fd */
1129 public final void close() { if(--refCount==0) _close(); }
1130 protected void _close() { /* noop*/ }
1132 FD dup() { refCount++; return this; }
1135 /** FileDescriptor class for normal files */
1136 public abstract static class SeekableFD extends FD {
1137 private final int flags;
1138 private final Seekable data;
1140 SeekableFD(Seekable data, int flags) { this.data = data; this.flags = flags; }
1142 protected abstract FStat _fstat();
1143 public int flags() { return flags; }
1145 Seekable seekable() { return data; }
1147 public int seek(int n, int whence) throws ErrnoException {
1150 case SEEK_SET: break;
1151 case SEEK_CUR: n += data.pos(); break;
1152 case SEEK_END: n += data.length(); break;
1157 } catch(IOException e) {
1158 throw new ErrnoException(ESPIPE);
1162 public int write(byte[] a, int off, int length) throws ErrnoException {
1163 if((flags&3) == RD_ONLY) throw new ErrnoException(EBADFD);
1164 // NOTE: There is race condition here but we can't fix it in pure java
1165 if((flags&O_APPEND) != 0) seek(0,SEEK_END);
1167 return data.write(a,off,length);
1168 } catch(IOException e) {
1169 throw new ErrnoException(EIO);
1173 public int read(byte[] a, int off, int length) throws ErrnoException {
1174 if((flags&3) == WR_ONLY) throw new ErrnoException(EBADFD);
1176 int n = data.read(a,off,length);
1177 return n < 0 ? 0 : n;
1178 } catch(IOException e) {
1179 throw new ErrnoException(EIO);
1183 protected void _close() { try { data.close(); } catch(IOException e) { /*ignore*/ } }
1186 public static class InputOutputStreamFD extends FD {
1187 private final InputStream is;
1188 private final OutputStream os;
1190 public InputOutputStreamFD(InputStream is) { this(is,null); }
1191 public InputOutputStreamFD(OutputStream os) { this(null,os); }
1192 public InputOutputStreamFD(InputStream is, OutputStream os) {
1195 if(is == null && os == null) throw new IllegalArgumentException("at least one stream must be supplied");
1198 public int flags() {
1199 if(is != null && os != null) return O_RDWR;
1200 if(is != null) return O_RDONLY;
1201 if(os != null) return O_WRONLY;
1202 throw new Error("should never happen");
1205 public void _close() {
1206 if(is != null) try { is.close(); } catch(IOException e) { /*ignore*/ }
1207 if(os != null) try { os.close(); } catch(IOException e) { /*ignore*/ }
1210 public int read(byte[] a, int off, int length) throws ErrnoException {
1211 if(is == null) return super.read(a,off,length);
1213 int n = is.read(a,off,length);
1214 return n < 0 ? 0 : n;
1215 } catch(IOException e) {
1216 throw new ErrnoException(EIO);
1220 public int write(byte[] a, int off, int length) throws ErrnoException {
1221 if(os == null) return super.write(a,off,length);
1223 os.write(a,off,length);
1225 } catch(IOException e) {
1226 throw new ErrnoException(EIO);
1230 public FStat _fstat() { return new FStat(); }
1233 static class TerminalFD extends InputOutputStreamFD {
1234 public TerminalFD(InputStream is) { this(is,null); }
1235 public TerminalFD(OutputStream os) { this(null,os); }
1236 public TerminalFD(InputStream is, OutputStream os) { super(is,os); }
1237 public void _close() { /* noop */ }
1238 public FStat _fstat() { return new FStat() { public int type() { return S_IFCHR; } public int mode() { return 0600; } }; }
1241 // This is pretty inefficient but it is only used for reading from the console on win32
1242 static class TextInputStream extends InputStream {
1243 private int pushedBack = -1;
1244 private final InputStream parent;
1245 public TextInputStream(InputStream parent) { this.parent = parent; }
1246 public int read() throws IOException {
1247 if(pushedBack != -1) { int c = pushedBack; pushedBack = -1; return c; }
1248 int c = parent.read();
1249 if(c == '\r' && (c = parent.read()) != '\n') { pushedBack = c; return '\r'; }
1252 public int read(byte[] buf, int pos, int len) throws IOException {
1254 if(pushedBack != -1 && len > 0) {
1255 buf[0] = (byte) pushedBack;
1257 pos++; len--; pb = true;
1259 int n = parent.read(buf,pos,len);
1260 if(n == -1) return -1;
1261 for(int i=0;i<n;i++) {
1262 if(buf[pos+i] == '\r') {
1264 int c = parent.read();
1265 if(c == '\n') buf[pos+i] = '\n';
1266 else pushedBack = c;
1267 } else if(buf[pos+i+1] == '\n') {
1268 System.arraycopy(buf,pos+i+1,buf,pos+i,len-i-1);
1273 return n + (pb ? 1 : 0);
1277 public static class FStat {
1278 public static final int S_IFIFO = 0010000;
1279 public static final int S_IFCHR = 0020000;
1280 public static final int S_IFDIR = 0040000;
1281 public static final int S_IFREG = 0100000;
1283 public int dev() { return 1; }
1284 public int inode() { return hashCode() & 0x7fff; }
1285 public int mode() { return 0; }
1286 public int type() { return S_IFIFO; }
1287 public int nlink() { return 0; }
1288 public int uid() { return 0; }
1289 public int gid() { return 0; }
1290 public int size() { return 0; }
1291 public int atime() { return 0; }
1292 public int mtime() { return 0; }
1293 public int ctime() { return 0; }
1294 public int blksize() { return 512; }
1295 public int blocks() { return (size()+blksize()-1)/blksize(); }
1298 static class HostFStat extends FStat {
1299 private final File f;
1300 private final boolean executable;
1301 public HostFStat(File f) { this(f,false); }
1302 public HostFStat(File f, boolean executable) {
1304 this.executable = executable;
1306 public int dev() { return 1; }
1307 public int inode() { return f.getName().hashCode() & 0xffff; }
1308 public int type() { return f.isDirectory() ? S_IFDIR : S_IFREG; }
1309 public int nlink() { return 1; }
1312 boolean canread = f.canRead();
1313 if(canread && (executable || f.isDirectory())) mode |= 0111;
1314 if(canread) mode |= 0444;
1315 if(f.canWrite()) mode |= 0222;
1318 public int size() { return (int) f.length(); }
1319 public int mtime() { return (int)(f.lastModified()/1000); }
1323 public static class ReadFaultException extends FaultException {
1324 public ReadFaultException(int addr) { super(addr); }
1326 public static class WriteFaultException extends FaultException {
1327 public WriteFaultException(int addr) { super(addr); }
1329 public static class FaultException extends ExecutionException {
1330 public final int addr;
1331 public final RuntimeException cause;
1332 public FaultException(int addr) { super("fault at: " + toHex(addr)); this.addr = addr; cause = null; }
1333 public FaultException(RuntimeException e) { super(e.toString()); addr = -1; cause = e; }
1335 public static class ExecutionException extends Exception {
1336 private String message = "(null)";
1337 private String location = "(unknown)";
1338 public ExecutionException() { /* noop */ }
1339 public ExecutionException(String s) { if(s != null) message = s; }
1340 void setLocation(String s) { location = s == null ? "(unknown)" : s; }
1341 public final String getMessage() { return message + " at " + location; }
1343 public static class CallException extends Exception {
1344 public CallException(String s) { super(s); }
1347 protected static class ErrnoException extends Exception {
1349 public ErrnoException(int errno) { super("Errno: " + errno); this.errno = errno; }
1353 protected static class CPUState {
1354 public CPUState() { /* noop */ }
1356 public int[] r = new int[32];
1357 /* Floating point regs */
1358 public int[] f = new int[32];
1363 public CPUState dup() {
1364 CPUState c = new CPUState();
1369 for(int i=0;i<32;i++) {
1377 public static class SecurityManager {
1378 public boolean allowRead(File f) { return true; }
1379 public boolean allowWrite(File f) { return true; }
1380 public boolean allowStat(File f) { return true; }
1381 public boolean allowUnlink(File f) { return true; }
1384 // Null pointer check helper function
1385 protected final void nullPointerCheck(int addr) throws ExecutionException {
1387 throw new ExecutionException("Attempted to dereference a null pointer " + toHex(addr));
1390 // Utility functions
1391 byte[] byteBuf(int size) {
1392 if(_byteBuf==null) _byteBuf = new byte[size];
1393 else if(_byteBuf.length < size)
1394 _byteBuf = new byte[min(max(_byteBuf.length*2,size),MAX_CHUNK)];
1398 static String getSystemProperty(String key) {
1400 return System.getProperty(key);
1401 } catch(SecurityException e) {
1406 /** Decode a packed string */
1407 protected static final int[] decodeData(String s, int words) {
1408 if(s.length() % 8 != 0) throw new IllegalArgumentException("string length must be a multiple of 8");
1409 if((s.length() / 8) * 7 < words*4) throw new IllegalArgumentException("string isn't big enough");
1410 int[] buf = new int[words];
1411 int prev = 0, left=0;
1412 for(int i=0,n=0;n<words;i+=8) {
1414 for(int j=0;j<8;j++) { l <<= 7; l |= s.charAt(i+j) & 0x7f; }
1415 if(left > 0) buf[n++] = prev | (int)(l>>>(56-left));
1416 if(n < words) buf[n++] = (int) (l >>> (24-left));
1417 left = (left + 8) & 0x1f;
1418 prev = (int)(l << left);
1423 static byte[] getBytes(String s) {
1425 return s.getBytes("ISO-8859-1");
1426 } catch(UnsupportedEncodingException e) {
1427 return null; // should never happen
1431 static byte[] getNullTerminatedBytes(String s) {
1432 byte[] buf1 = getBytes(s);
1433 byte[] buf2 = new byte[buf1.length+1];
1434 System.arraycopy(buf1,0,buf2,0,buf1.length);
1438 final static String toHex(int n) { return "0x" + Long.toString(n & 0xffffffffL, 16); }
1439 final static int min(int a, int b) { return a < b ? a : b; }
1440 final static int max(int a, int b) { return a > b ? a : b; }