--- /dev/null
+// Copyright 2003 Brian Alliet
+// Based on org.xwt.imp.MIPS by Adam Megacz
+// Portions Copyright 2003 Adam Megacz
+
+package org.xwt.mips;
+
+import org.xwt.mips.util.*;
+import java.io.*;
+import java.util.Arrays;
+
+// FEATURE: Look over the public API, make sure we're exposing a bare minimum
+// (we might make this an interface in the future)
+
+public abstract class Runtime implements UsermodeConstants,Registers {
+ /** Pages are 4k in size */
+ protected final int PAGE_SIZE;
+ protected final int PAGE_WORDS;
+ protected final int PAGE_SHIFT;
+ protected final int TOTAL_PAGES;
+ /** This is the upper limit of the pages allocated by the sbrk() syscall. */
+ protected final int BRK_LIMIT;
+ protected final int STACK_BOTTOM;
+
+ /** This is the maximum size of command line arguments */
+ public final static int ARGS_MAX = 1024*1024;
+
+ /** True if we allow empty pages (_emptyPage) to exist in memory.
+ Empty pages are pages which are allocated by the program but do not contain any
+ data yet (they are all 0s). If empty pages are allowed subclasses must always
+ access main memory with the memRead and memWrite functions */
+ private final boolean allowEmptyPages;
+ /** the "empty page" */
+ private final static int[] _emptyPage = new int[0];
+
+ protected final static boolean isEmptyPage(int[] page) { return page == _emptyPage; }
+
+ /** Returns a new empty page (_emptyPage is empty pages are enabled or a new zero'd page) */
+ private final int[] emptyPage() { return allowEmptyPages ? _emptyPage : new int[PAGE_WORDS]; }
+
+ /** Readable main memory pages */
+ protected final int[][] readPages;
+ /** Writable main memory pages.
+ If the page is writable writePages[x] == readPages[x]; if not writePages[x] == null. */
+ protected final int[][] writePages;
+
+ /** The current break between the heap and unallocated memory */
+ protected int brkAddr;
+
+ /** The program's entry point */
+ protected int entryPoint;
+
+ /** The location of the _user_info block (or 0 is there is none) */
+ protected int userInfoBase;
+ protected int userInfoSize;
+
+ /** The location of the global pointer */
+ protected int gp;
+
+ /** When the process started */
+ private long startTime;
+
+ /** State constant: There is no program loaded in memory */
+ public final static int UNINITIALIZED = 0;
+ /** Text/Data loaded in memory */
+ public final static int INITIALIZED = 1;
+ /** Program is executing instructions */
+ public final static int RUNNING = 2;
+ /** Prgram has been started but is paused */
+ public final static int PAUSED = 3;
+ /** Program is executing a callJava() method */
+ public final static int CALLJAVA = 4;
+ /** Program has exited (it cannot currently be restarted) */
+ public final static int DONE = 5;
+
+ /** The current state (UNINITIALIZED, INITIALIZED, RUNNING, PAUSED, or DONE) */
+ protected int state = UNINITIALIZED;
+ /** @see Runtime#state state */
+ public final int getState() { return state; }
+
+ /** The exit status if the process (only valid if state==DONE)
+ @see Runtime#state */
+ protected int exitStatus;
+ public ExecutionException exitException;
+
+ /** Maximum number of open file descriptors */
+ final static int OPEN_MAX = 256;
+ /** Table containing all open file descriptors. (Entries are null if the fd is not in use */
+ FD[] fds = new FD[OPEN_MAX];
+
+ /** Temporary buffer for read/write operations */
+ private byte[] _byteBuf = null;
+ /** Max size of temporary buffer
+ @see Runtime#_byteBuf */
+ private final static int MAX_CHUNK = 15*1024*1024;
+
+ /** Subclasses should actually execute program in this method. They should continue
+ executing until state != RUNNING. Only syscall() can modify state. It is safe
+ to only check the state attribute after a call to syscall() */
+ protected abstract void _execute() throws ExecutionException;
+
+ /** Subclasses should return the address of the symbol <i>symbol</i> or -1 it it doesn't exits in this method
+ This method is only required if the call() function is used */
+ protected int lookupSymbol(String symbol) { return -1; }
+
+ /** Subclasses should returns a CPUState object representing the cpu state */
+ protected abstract CPUState getCPUState();
+
+ /** Subclasses should set the CPUState to the state held in <i>state</i> */
+ protected abstract void setCPUState(CPUState state);
+
+ static void checkPageSize(int pageSize, int totalPages) throws IllegalArgumentException {
+ if(pageSize < 256) throw new IllegalArgumentException("pageSize too small");
+ if((pageSize&(pageSize-1)) != 0) throw new IllegalArgumentException("pageSize must be a power of two");
+ if((totalPages&(totalPages-1)) != 0) throw new IllegalArgumentException("totalPages must be a power of two");
+ if(totalPages != 1 && totalPages < 256) throw new IllegalArgumentException("totalPages too small");
+ if(totalPages * pageSize < 4*1024*1024) throw new IllegalArgumentException("total memory too small (" + totalPages + "*" + pageSize + ")");
+ }
+
+ protected Runtime(int pageSize, int totalPages, boolean allowEmptyPages) {
+ this.allowEmptyPages = allowEmptyPages;
+
+ checkPageSize(pageSize,totalPages);
+
+ PAGE_SIZE = pageSize;
+ PAGE_WORDS = pageSize>>>2;
+ int pageShift = 0;
+ while(pageSize>>>pageShift != 1) pageShift++;
+ PAGE_SHIFT = pageShift;
+
+ TOTAL_PAGES = totalPages;
+
+ readPages = new int[TOTAL_PAGES][];
+ writePages = new int[TOTAL_PAGES][];
+
+ if(TOTAL_PAGES == 1) {
+ readPages[0] = writePages[0] = new int[PAGE_WORDS];
+ BRK_LIMIT = STACK_BOTTOM = 0;
+ } else {
+ int stackPages = max(TOTAL_PAGES>>>8,(1024*1024)>>>PAGE_SHIFT);
+ STACK_BOTTOM = (TOTAL_PAGES - stackPages) * PAGE_SIZE;
+ // leave some unmapped pages between the stack and the heap
+ BRK_LIMIT = STACK_BOTTOM - 4*PAGE_SIZE;
+
+ for(int i=0;i<stackPages;i++)
+ readPages[TOTAL_PAGES-1-i] = writePages[TOTAL_PAGES-1-i] = emptyPage();
+ }
+
+ addFD(new StdinFD(System.in));
+ addFD(new StdoutFD(System.out));
+ addFD(new StdoutFD(System.err));
+ }
+
+ /** Copy everything from <i>src</i> to <i>addr</i> initializing uninitialized pages if required.
+ Newly initalized pages will be marked read-only if <i>ro</i> is set */
+ protected final void initPages(int[] src, int addr, boolean ro) {
+ for(int i=0;i<src.length;) {
+ int page = addr >>> PAGE_SHIFT;
+ int start = (addr&(PAGE_SIZE-1))>>2;
+ int elements = min(PAGE_WORDS-start,src.length-i);
+ if(readPages[page]==null) {
+ initPage(page,ro);
+ } else if(!ro) {
+ if(writePages[page] == null) writePages[page] = readPages[page];
+ }
+ System.arraycopy(src,i,readPages[page],start,elements);
+ i += elements;
+ addr += elements*4;
+ }
+ }
+
+ /** Initialize <i>words</i> of pages starting at <i>addr</i> to 0 */
+ protected final void clearPages(int addr, int words) {
+ for(int i=0;i<words;) {
+ int page = addr >>> PAGE_SHIFT;
+ int start = (addr&(PAGE_SIZE-1))>>2;
+ int elements = min(PAGE_WORDS-start,words-i);
+ if(readPages[page]==null) {
+ readPages[page] = writePages[page] = emptyPage();
+ } else {
+ if(writePages[page] == null) writePages[page] = readPages[page];
+ for(int j=start;j<start+elements;j++) writePages[page][j] = 0;
+ }
+ i += elements;
+ addr += elements*4;
+ }
+ }
+
+ /** Copies <i>length</i> bytes from the processes memory space starting at
+ <i>addr</i> INTO a java byte array <i>a</i> */
+ public final void copyin(int addr, byte[] buf, int count) throws ReadFaultException {
+ int x=0;
+ if((addr&3)!=0) {
+ int word = memRead(addr&~3);
+ switch(addr&3) {
+ case 1: buf[x++] = (byte)((word>>>16)&0xff); if(--count==0) break;
+ case 2: buf[x++] = (byte)((word>>> 8)&0xff); if(--count==0) break;
+ case 3: buf[x++] = (byte)((word>>> 0)&0xff); if(--count==0) break;
+ }
+ addr = (addr&~3)+4;
+ }
+ if((count&~3) != 0) {
+ int c = count>>>2;
+ int a = addr>>>2;
+ while(c != 0) {
+ int[] page = readPages[a >>> (PAGE_SHIFT-2)];
+ if(page == null) throw new ReadFaultException(a<<2);
+ int index = a&(PAGE_WORDS-1);
+ int n = min(c,PAGE_WORDS-index);
+ if(page != _emptyPage) {
+ for(int i=0;i<n;i++,x+=4) {
+ int word = page[index+i];
+ buf[x+0] = (byte)((word>>>24)&0xff); buf[x+1] = (byte)((word>>>16)&0xff);
+ buf[x+2] = (byte)((word>>> 8)&0xff); buf[x+3] = (byte)((word>>> 0)&0xff);
+ }
+ }
+ a += n; c -=n;
+ }
+ addr = a<<2; count &=3;
+ }
+ if(count != 0) {
+ int word = memRead(addr);
+ switch(count) {
+ case 3: buf[x+2] = (byte)((word>>>8)&0xff);
+ case 2: buf[x+1] = (byte)((word>>>16)&0xff);
+ case 1: buf[x+0] = (byte)((word>>>24)&0xff);
+ }
+ }
+ }
+
+ /** Copies <i>length</i> bytes OUT OF the java array <i>a</i> into the processes memory
+ space at <i>addr</i> */
+ public final void copyout(byte[] buf, int addr, int count) throws FaultException {
+ int x=0;
+ if((addr&3)!=0) {
+ int word = memRead(addr&~3);
+ switch(addr&3) {
+ case 1: word = (word&0xff00ffff)|((buf[x++]&0xff)<<16); if(--count==0) break;
+ case 2: word = (word&0xffff00ff)|((buf[x++]&0xff)<< 8); if(--count==0) break;
+ case 3: word = (word&0xffffff00)|((buf[x++]&0xff)<< 0); if(--count==0) break;
+ }
+ memWrite(addr&~3,word);
+ addr += x;
+ }
+ if((count&~3) != 0) {
+ int c = count>>>2;
+ int a = addr>>>2;
+ while(c != 0) {
+ int[] page = writePages[a >>> (PAGE_SHIFT-2)];
+ if(page == null) throw new WriteFaultException(a<<2);
+ if(page == _emptyPage) page = initPage(a >>> (PAGE_SHIFT-2));
+ int index = a&(PAGE_WORDS-1);
+ int n = min(c,PAGE_WORDS-index);
+ for(int i=0;i<n;i++,x+=4)
+ page[index+i] = ((buf[x+0]&0xff)<<24)|((buf[x+1]&0xff)<<16)|((buf[x+2]&0xff)<<8)|((buf[x+3]&0xff)<<0);
+ a += n; c -=n;
+ }
+ addr = a<<2; count&=3;
+ }
+ if(count != 0) {
+ int word = memRead(addr);
+ switch(count) {
+ case 1: word = (word&0x00ffffff)|((buf[x+0]&0xff)<<24); break;
+ case 2: word = (word&0x0000ffff)|((buf[x+0]&0xff)<<24)|((buf[x+1]&0xff)<<16); break;
+ case 3: word = (word&0x000000ff)|((buf[x+0]&0xff)<<24)|((buf[x+1]&0xff)<<16)|((buf[x+2]&0xff)<<8); break;
+ }
+ memWrite(addr,word);
+ }
+ }
+
+ public final void memcpy(int dst, int src, int count) throws FaultException {
+ if((dst&3) == 0 && (src&3)==0) {
+ if((count&~3) != 0) {
+ int c = count>>2;
+ int s = src>>>2;
+ int d = dst>>>2;
+ while(c != 0) {
+ int[] srcPage = readPages[s>>>(PAGE_SHIFT-2)];
+ if(srcPage == null) throw new ReadFaultException(s<<2);
+ int[] dstPage = writePages[d>>>(PAGE_SHIFT-2)];
+ if(dstPage == null) throw new WriteFaultException(d<<2);
+ int srcIndex = (s&(PAGE_WORDS-1));
+ int dstIndex = (d&(PAGE_WORDS-1));
+ int n = min(c,PAGE_WORDS-max(srcIndex,dstIndex));
+ if(srcPage != _emptyPage) {
+ if(dstPage == _emptyPage) dstPage = initPage(d>>>(PAGE_SHIFT-2));
+ System.arraycopy(srcPage,srcIndex,dstPage,dstIndex,n);
+ } else if(srcPage == _emptyPage && dstPage != _emptyPage) {
+ Arrays.fill(dstPage,dstIndex,dstIndex+n,0);
+ }
+ s += n; d += n; c -= n;
+ }
+ src = s<<2; dst = d<<2; count&=3;
+ }
+ if(count != 0) {
+ int word1 = memRead(src);
+ int word2 = memRead(dst);
+ switch(count) {
+ case 1: memWrite(dst,(word1&0xff000000)|(word2&0x00ffffff)); break;
+ case 2: memWrite(dst,(word1&0xffff0000)|(word2&0x0000ffff)); break;
+ case 3: memWrite(dst,(word1&0xffffff00)|(word2&0x000000ff)); break;
+ }
+ }
+ } else {
+ while(count > 0) {
+ int n = min(count,MAX_CHUNK);
+ byte[] buf = byteBuf(n);
+ copyin(src,buf,n);
+ copyout(buf,dst,n);
+ count -= n; src += n; dst += n;
+ }
+ }
+ }
+
+ public final void memset(int addr, int ch, int count) throws FaultException {
+ int fourBytes = ((ch&0xff)<<24)|((ch&0xff)<<16)|((ch&0xff)<<8)|((ch&0xff)<<0);
+ if((addr&3)!=0) {
+ int word = memRead(addr&~3);
+ switch(addr&3) {
+ case 1: word = (word&0xff00ffff)|((ch&0xff)<<16); if(--count==0) break;
+ case 2: word = (word&0xffff00ff)|((ch&0xff)<< 8); if(--count==0) break;
+ case 3: word = (word&0xffffff00)|((ch&0xff)<< 0); if(--count==0) break;
+ }
+ memWrite(addr&~3,word);
+ addr = (addr&~3)+4;
+ }
+ if((count&~3) != 0) {
+ int c = count>>2;
+ int a = addr>>>2;
+ while(c != 0) {
+ int[] page = readPages[a>>>(PAGE_SHIFT-2)];
+ if(page == null) throw new WriteFaultException(a<<2);
+ int index = (a&(PAGE_WORDS-1));
+ int n = min(c,PAGE_WORDS-index);
+ if(page != _emptyPage || ch != 0) {
+ if(page == _emptyPage) page = initPage(a>>>(PAGE_SHIFT-2));
+ Arrays.fill(page,index,index+n,fourBytes);
+ }
+ a += n; c -= n;
+ }
+ addr = a<<2; count&=3;
+ }
+ if(count != 0) {
+ int word = memRead(addr);
+ switch(count) {
+ case 1: word = (word&0x00ffffff)|(fourBytes&0xff000000); break;
+ case 2: word = (word&0x0000ffff)|(fourBytes&0xffff0000); break;
+ case 3: word = (word&0x000000ff)|(fourBytes&0xffffff00); break;
+ }
+ memWrite(addr,word);
+ }
+ }
+
+ /** Read a word from the processes memory at <i>addr</i> */
+ public final int memRead(int addr) throws ReadFaultException {
+ if((addr & 3) != 0) throw new ReadFaultException(addr);
+ return unsafeMemRead(addr);
+ }
+
+ protected final int unsafeMemRead(int addr) throws ReadFaultException {
+ int page = addr >>> PAGE_SHIFT;
+ int entry = (addr >>> 2) & (PAGE_WORDS-1);
+ try {
+ return readPages[page][entry];
+ } catch(ArrayIndexOutOfBoundsException e) {
+ if(page < 0) throw e; // should never happen
+ if(page >= readPages.length) throw new ReadFaultException(addr);
+ if(readPages[page] != _emptyPage) throw e; // should never happen
+ initPage(page);
+ return 0;
+ } catch(NullPointerException e) {
+ throw new ReadFaultException(addr);
+ }
+ }
+
+ /** Writes a word to the processes memory at <i>addr</i> */
+ public final void memWrite(int addr, int value) throws WriteFaultException {
+ if((addr & 3) != 0) throw new WriteFaultException(addr);
+ unsafeMemWrite(addr,value);
+ }
+
+ protected final void unsafeMemWrite(int addr, int value) throws WriteFaultException {
+ int page = addr >>> PAGE_SHIFT;
+ int entry = (addr>>>2)&(PAGE_WORDS-1);
+ try {
+ writePages[page][entry] = value;
+ } catch(ArrayIndexOutOfBoundsException e) {
+ if(page < 0) throw e;// should never happen
+ if(page >= writePages.length) throw new WriteFaultException(addr);
+ if(readPages[page] != _emptyPage) throw e; // should never happen
+ initPage(page);
+ writePages[page][entry] = value;
+ } catch(NullPointerException e) {
+ throw new WriteFaultException(addr);
+ }
+ }
+
+ /** Created a new non-empty writable page at page number <i>page</i> */
+ private final int[] initPage(int page) { return initPage(page,false); }
+ /** Created a new non-empty page at page number <i>page</i>. If <i>ro</i> is set the page will be read-only */
+ private final int[] initPage(int page, boolean ro) {
+ int[] buf = new int[PAGE_WORDS];
+ writePages[page] = ro ? null : buf;
+ readPages[page] = buf;
+ return buf;
+ }
+
+ /** Returns the exit status of the process. (only valid if state == DONE)
+ @see Runtime#state */
+ public final int exitStatus() {
+ if(state != DONE) throw new IllegalStateException("exitStatus() called in an inappropriate state");
+ return exitStatus;
+ }
+
+ private int addStringArray(String[] strings, int topAddr) {
+ int count = strings.length;
+ int total = 0; /* null last table entry */
+ for(int i=0;i<count;i++) total += strings[i].length() + 1;
+ if(total >= ARGS_MAX) throw new IllegalArgumentException("arguments/environ too big");
+ total += (count+1)*4;
+ int start = (topAddr - total)&~3;
+ int addr = start + (count+1)*4;
+ int[] table = new int[count+1];
+ try {
+ for(int i=0;i<count;i++) {
+ byte[] a = getBytes(strings[i]);
+ table[i] = addr;
+ copyout(a,addr,a.length);
+ memset(addr+a.length,0,1);
+ addr += a.length + 1;
+ }
+ addr=start;
+ for(int i=0;i<count+1;i++) {
+ memWrite(addr,table[i]);
+ addr += 4;
+ }
+ } catch(FaultException e) {
+ // should never happen
+ throw new Error(e);
+ }
+ return start;
+ }
+
+ protected String[] createEnv(String[] extra) { if(extra == null) extra = new String[0]; return extra; }
+
+ /** Sets word number <i>index</i> in the _user_info table to <i>word</i>
+ * The user_info table is a chunk of memory in the program's memory defined by the
+ * symbol "user_info". The compiler/interpreter automatically determine the size
+ * and location of the user_info table from the ELF symbol table. setUserInfo and
+ * getUserInfo are used to modify the words in the user_info table. */
+ public void setUserInfo(int index, int word) {
+ if(index < 0 || index >= userInfoSize/4) throw new IndexOutOfBoundsException("setUserInfo called with index >= " + (userInfoSize/4));
+ try {
+ memWrite(userInfoBase+index*4,word);
+ } catch(FaultException e) { throw new Error("should never happen: " + e); }
+ }
+
+ /** Returns the word in the _user_info table entry <i>index</i>
+ @see Runtime#setUserInfo(int,int) setUserInfo */
+ public int getUserInfo(int index) {
+ if(index < 0 || index >= userInfoSize/4) throw new IndexOutOfBoundsException("setUserInfo called with index >= " + (userInfoSize/4));
+ try {
+ return memRead(userInfoBase+index*4);
+ } catch(FaultException e) { throw new Error("should never happen: " + e); }
+ }
+
+ /** Calls _execute() (subclass's execute()) and catches exceptions */
+ private void __execute() {
+ try {
+ _execute();
+ } catch(FaultException e) {
+ e.printStackTrace();
+ sys_exit(128+11); // SIGSEGV
+ exitException = e;
+ } catch(ExecutionException e) {
+ e.printStackTrace();
+ System.err.println(e);
+ sys_exit(128+4); // SIGILL
+ exitException = e;
+ }
+ }
+
+ /** Executes the process until the PAUSE syscall is invoked or the process exits. Returns true if the process exited. */
+ public final boolean execute() {
+ if(state != PAUSED) throw new IllegalStateException("execute() called in inappropriate state");
+ if(startTime == 0) startTime = System.currentTimeMillis();
+ state = RUNNING;
+ __execute();
+ if(state != PAUSED && state != DONE) throw new IllegalStateException("execute() ended up in an inappropriate state (" + state + ")");
+ return state == DONE;
+ }
+
+ public final int run() { return run(null); }
+ public final int run(String argv0, String[] rest) {
+ String[] args = new String[rest.length+1];
+ System.arraycopy(rest,0,args,1,rest.length);
+ args[0] = argv0;
+ return run(args);
+ }
+ public final int run(String[] args) { return run(args,null); }
+
+ /** Runs the process until it exits and returns the exit status.
+ If the process executes the PAUSE syscall execution will be paused for 500ms and a warning will be displayed */
+ public final int run(String[] args, String[] env) {
+ start(args,env);
+ for(;;) {
+ if(execute()) break;
+ System.err.println("WARNING: Pause requested while executing run()");
+ try { Thread.sleep(500); } catch(InterruptedException e) { /* noop */ }
+ }
+ return exitStatus();
+ }
+
+ public final void start() { start(null); }
+ public final void start(String[] args) { start(args,null); }
+
+ /** Initializes the process and prepairs it to be executed with execute() */
+ public final void start(String[] args, String[] environ) {
+ int sp, argsAddr, envAddr;
+ if(state != INITIALIZED) throw new IllegalStateException("start() called in inappropriate state");
+
+ if(args == null) args = new String[]{getClass().getName()};
+
+ sp = TOTAL_PAGES*PAGE_SIZE-512;
+ sp = argsAddr = addStringArray(args,sp);
+ sp = envAddr = addStringArray(createEnv(environ),sp);
+ sp &= ~15;
+
+ CPUState cpuState = new CPUState();
+ cpuState.r[A0] = argsAddr;
+ cpuState.r[A1] = envAddr;
+ cpuState.r[SP] = sp;
+ cpuState.r[RA] = 0xdeadbeef;
+ cpuState.r[GP] = gp;
+ cpuState.pc = entryPoint;
+ setCPUState(cpuState);
+
+ state = PAUSED;
+
+ _start();
+ }
+
+ /** Hook for subclasses to do their own startup */
+ protected void _start() { /* noop */ }
+
+ public final int call(String sym) throws CallException { return call(sym,0,0,0,0,0,0,0); }
+ public final int call(String sym, int a0) throws CallException { return call(sym,a0,0,0,0,0,0,0); }
+ public final int call(String sym, int a0, int a1) throws CallException { return call(sym,a0,a1,0,0,0,0,0); }
+ public final int call(String sym, int a0, int a1, int a2) throws CallException { return call(sym,a0,a1,a2,0,0,0,0); }
+ public final int call(String sym, int a0, int a1, int a2, int a3) throws CallException { return call(sym,a0,a1,a2,a3,0,0,0); }
+ public final int call(String sym, int a0, int a1, int a2, int a3, int a4) throws CallException { return call(sym,a0,a1,a2,a3,a4,0,0); }
+ public final int call(String sym, int a0, int a1, int a2, int a3, int a4, int a5) throws CallException { return call(sym,a0,a1,a2,a3,a4,a5,0); }
+
+ /** Calls a function in the process with the given arguments */
+ public final int call(String sym, int a0, int a1, int a2, int a3, int a4, int a5, int a6) throws CallException {
+ int func = lookupSymbol(sym);
+ if(func == -1) throw new CallException(sym + " not found");
+ int helper = lookupSymbol("_call_helper");
+ if(helper == -1) throw new CallException("_call_helper not found");
+ return call(helper,func,a0,a1,a2,a3,a4,a5,a6);
+ }
+
+ /** Executes the code at <i>addr</i> in the process setting A0-A3 and S0-S3 to the given arguments
+ and returns the contents of V1 when the the pause syscall is invoked */
+ public final int call(int addr, int a0, int a1, int a2, int a3, int s0, int s1, int s2, int s3) {
+ if(state != PAUSED && state != CALLJAVA) throw new IllegalStateException("call() called in inappropriate state");
+ int oldState = state;
+ CPUState saved = getCPUState();
+ CPUState cpustate = new CPUState();
+ cpustate.r[SP] = saved.r[SP]&~15;
+ cpustate.r[RA] = 0xdeadbeef;
+ cpustate.r[A0] = a0;
+ cpustate.r[A1] = a1;
+ cpustate.r[A2] = a2;
+ cpustate.r[A3] = a3;
+ cpustate.r[S0] = s0;
+ cpustate.r[S1] = s1;
+ cpustate.r[S2] = s2;
+ cpustate.r[S3] = s3;
+ cpustate.r[GP] = gp;
+ cpustate.pc = addr;
+
+ state = RUNNING;
+
+ setCPUState(cpustate);
+ __execute();
+ cpustate = getCPUState();
+ setCPUState(saved);
+
+ if(state != PAUSED)
+ System.out.println("WARNING: Process exit()ed while servicing a call() request");
+ else
+ state = oldState;
+
+ return cpustate.r[V1];
+ }
+
+ // FEATURE: This is ugly - we should have some kind of way to specify a callback rather than requiring subclassing
+ protected int callJava(int a, int b, int c, int d) {
+ System.err.println("WARNING: Default implementation of callJava() called with args " + toHex(a) + "," + toHex(b) + "," + toHex(c) + "," + toHex(d));
+ return 0;
+ }
+
+ /** Determines if the process can access <i>fileName</i>. The default implementation simply logs
+ the request and allows it */
+ protected boolean allowFileAccess(String fileName, boolean write) {
+ //System.err.println("Allowing " + (write?"write":"read-only") + " access to " + fileName);
+ return true;
+ }
+
+ /** Allocated an entry in the FileDescriptor table for <i>fd</i> and returns the number.
+ Returns -1 if the table is full. This can be used by subclasses to use custom file
+ descriptors */
+ public int addFD(FD fd) {
+ int i;
+ for(i=0;i<OPEN_MAX;i++) if(fds[i] == null) break;
+ if(i==OPEN_MAX) return -1;
+ fds[i] = fd;
+ return i;
+ }
+
+ /** Closes file descriptor <i>fdn</i> and removes it from the file descriptor table */
+ public boolean closeFD(int fdn) {
+ if(fdn < 0 || fdn >= OPEN_MAX) return false;
+ if(fds[fdn] == null) return false;
+ fds[fdn].close();
+ fds[fdn] = null;
+ return true;
+ }
+
+ // FEATURE: These should be pulled in from UsermodeConstants but fcntl.h is hard to parse
+ public static final int RD_ONLY = 0;
+ public static final int WR_ONLY = 1;
+ public static final int RDWR = 2;
+
+ public static final int O_CREAT = 0x0200;
+ public static final int O_EXCL = 0x0800;
+ public static final int O_APPEND = 0x0008;
+ public static final int O_TRUNC = 0x0400;
+ public static final int O_NONBLOCK = 0x4000;
+
+ // FEATURE: Lots of duplicate code between this and UnixRuntime.HostFS.open()
+ protected FD open(String path, int flags, int mode) throws IOException {
+ final File f = new File(path);
+ // NOTE: createNewFile is a Java2 function
+ if((flags & (O_EXCL|O_CREAT)) == (O_EXCL|O_CREAT))
+ if(!f.createNewFile()) throw new ErrnoException(EEXIST);
+ if(!f.exists() && (flags&O_CREAT) == 0) return null;
+ if(f.isDirectory()) return null;
+ final SeekableFile sf = new SeekableFile(path,mode!=RD_ONLY);
+ if((flags&O_TRUNC)!=0) sf.setLength(0);
+ return new SeekableFD(sf,flags) {
+ protected FStat _fstat() { return new HostFStat(f) {
+ public int size() {
+ try { return sf.length(); } catch(IOException e) { return 0; }
+ }
+ };}
+ };
+ }
+
+ /** The open syscall */
+ private int sys_open(int addr, int flags, int mode) {
+ if((flags & O_NONBLOCK) != 0) {
+ System.err.println("WARNING: O_NONBLOCK not supported");
+ return -EOPNOTSUPP;
+ }
+
+ try {
+ FD fd = open(cstring(addr),flags,mode);
+ if(fd == null) return -ENOENT;
+ int fdn = addFD(fd);
+ if(fdn == -1) {
+ fd.close();
+ return -ENFILE;
+ }
+ return fdn;
+ }
+ catch(ErrnoException e) { return -e.errno; }
+ catch(FileNotFoundException e) {
+ if(e.getMessage() != null && e.getMessage().indexOf("Permission denied") >= 0) return -EACCES;
+ return -ENOENT;
+ }
+ catch(IOException e) { return -EIO; }
+ catch(FaultException e) { return -EFAULT; }
+ }
+
+ /** The write syscall */
+ private int sys_write(int fdn, int addr, int count) {
+ count = Math.min(count,MAX_CHUNK);
+ if(fdn < 0 || fdn >= OPEN_MAX) return -EBADFD;
+ if(fds[fdn] == null || !fds[fdn].writable()) return -EBADFD;
+ try {
+ byte[] buf = byteBuf(count);
+ copyin(addr,buf,count);
+ return fds[fdn].write(buf,0,count);
+ } catch(FaultException e) {
+ System.err.println(e);
+ return -EFAULT;
+ } catch(IOException e) {
+ // FEATURE: We should support signals and send a SIGPIPE
+ if(e.getMessage().equals("Pipe closed")) return sys_exit(128+13);
+ System.err.println(e);
+ return -EIO;
+ }
+ }
+
+ /** The read syscall */
+ private int sys_read(int fdn, int addr, int count) {
+ count = Math.min(count,MAX_CHUNK);
+ if(fdn < 0 || fdn >= OPEN_MAX) return -EBADFD;
+ if(fds[fdn] == null || !fds[fdn].readable()) return -EBADFD;
+ try {
+ byte[] buf = byteBuf(count);
+ int n = fds[fdn].read(buf,0,count);
+ copyout(buf,addr,n);
+ return n;
+ } catch(FaultException e) {
+ System.err.println(e);
+ return -EFAULT;
+ } catch(IOException e) {
+ System.err.println(e);
+ return -EIO;
+ }
+ }
+
+ /** The close syscall */
+ private int sys_close(int fdn) {
+ return closeFD(fdn) ? 0 : -EBADFD;
+ }
+
+
+ /** The seek syscall */
+ private int sys_lseek(int fdn, int offset, int whence) {
+ if(fdn < 0 || fdn >= OPEN_MAX) return -EBADFD;
+ if(fds[fdn] == null) return -EBADFD;
+ if(whence != SEEK_SET && whence != SEEK_CUR && whence != SEEK_END) return -EINVAL;
+ try {
+ int n = fds[fdn].seek(offset,whence);
+ return n < 0 ? -ESPIPE : n;
+ } catch(IOException e) {
+ return -ESPIPE;
+ }
+ }
+
+ /** The stat/fstat syscall helper */
+ int stat(FStat fs, int addr) {
+ try {
+ memWrite(addr+0,(fs.dev()<<16)|(fs.inode()&0xffff)); // st_dev (top 16), // st_ino (bottom 16)
+ memWrite(addr+4,((fs.type()&0xf000))|(fs.mode()&0xfff)); // st_mode
+ memWrite(addr+8,1<<16); // st_nlink (top 16) // st_uid (bottom 16)
+ memWrite(addr+12,0); // st_gid (top 16) // st_rdev (bottom 16)
+ memWrite(addr+16,fs.size()); // st_size
+ memWrite(addr+20,fs.atime()); // st_atime
+ // memWrite(addr+24,0) // st_spare1
+ memWrite(addr+28,fs.mtime()); // st_mtime
+ // memWrite(addr+32,0) // st_spare2
+ memWrite(addr+36,fs.ctime()); // st_ctime
+ // memWrite(addr+40,0) // st_spare3
+ memWrite(addr+44,fs.blksize()); // st_bklsize;
+ memWrite(addr+48,fs.blocks()); // st_blocks
+ // memWrite(addr+52,0) // st_spare4[0]
+ // memWrite(addr+56,0) // st_spare4[1]
+ } catch(FaultException e) {
+ System.err.println(e);
+ return -EFAULT;
+ }
+ return 0;
+ }
+
+ /** The fstat syscall */
+ private int sys_fstat(int fdn, int addr) {
+ if(fdn < 0 || fdn >= OPEN_MAX) return -EBADFD;
+ if(fds[fdn] == null) return -EBADFD;
+ return stat(fds[fdn].fstat(),addr);
+ }
+
+ /*
+ struct timeval {
+ long tv_sec;
+ long tv_usec;
+ };
+ */
+ private int sys_gettimeofday(int timevalAddr, int timezoneAddr) {
+ long now = System.currentTimeMillis();
+ int tv_sec = (int)(now / 1000);
+ int tv_usec = (int)((now%1000)*1000);
+ try {
+ memWrite(timevalAddr+0,tv_sec);
+ memWrite(timevalAddr+4,tv_usec);
+ return 0;
+ } catch(FaultException e) {
+ return -EFAULT;
+ }
+ }
+
+ private int sys_sleep(int sec) {
+ if(sec < 0) sec = Integer.MAX_VALUE;
+ try {
+ Thread.sleep((long)sec*1000);
+ return 0;
+ } catch(InterruptedException e) {
+ return -1;
+ }
+ }
+
+ /*
+ #define _CLOCKS_PER_SEC_ 1000
+ #define _CLOCK_T_ unsigned long
+ struct tms {
+ clock_t tms_utime;
+ clock_t tms_stime;
+ clock_t tms_cutime;
+ clock_t tms_cstime;
+ };*/
+
+ private int sys_times(int tms) {
+ long now = System.currentTimeMillis();
+ int userTime = (int)((now - startTime)/16);
+ int sysTime = (int)((now - startTime)/16);
+
+ try {
+ if(tms!=0) {
+ memWrite(tms+0,userTime);
+ memWrite(tms+4,sysTime);
+ memWrite(tms+8,userTime);
+ memWrite(tms+12,sysTime);
+ }
+ } catch(FaultException e) {
+ return -EFAULT;
+ }
+ return (int)now;
+ }
+
+ private int sys_sysconf(int n) {
+ switch(n) {
+ case _SC_CLK_TCK: return 1000;
+ default:
+ System.err.println("WARNING: Attempted to use unknown sysconf key: " + n);
+ return -EINVAL;
+ }
+ }
+
+ /** The sbrk syscall. This can also be used by subclasses to allocate memory.
+ <i>incr</i> is how much to increase the break by */
+ public int sbrk(int incr) {
+ if(incr < 0) return -ENOMEM;
+ if(incr==0) return brkAddr;
+ incr = (incr+3)&~3;
+ int oldBrk = brkAddr;
+ int newBrk = oldBrk + incr;
+ if(TOTAL_PAGES == 1) {
+ CPUState state = getCPUState();
+ if(newBrk >= state.r[SP] - 65536) {
+ System.err.println("WARNING: brk too close to stack pointer");
+ return -ENOMEM;
+ }
+ } else if(newBrk >= BRK_LIMIT) {
+ System.err.println("WARNING: Hit BRK_LIMIT");
+ return -ENOMEM;
+ }
+ if(TOTAL_PAGES != 1) {
+ try {
+ for(int i=(oldBrk+PAGE_SIZE-1)>>>PAGE_SHIFT;i<((newBrk+PAGE_SIZE-1)>>>PAGE_SHIFT);i++)
+ readPages[i] = writePages[i] = emptyPage();
+ } catch(OutOfMemoryError e) {
+ System.err.println("WARNING: Caught OOM Exception in sbrk: " + e);
+ return -ENOMEM;
+ }
+ }
+ brkAddr = newBrk;
+ return oldBrk;
+ }
+
+ /** The getpid syscall */
+ private int sys_getpid() { return getPid(); }
+ protected int getPid() { return 1; }
+
+ private int sys_calljava(int a, int b, int c, int d) {
+ if(state != RUNNING) throw new IllegalStateException("wound up calling sys_calljava while not in RUNNING");
+ state = CALLJAVA;
+ int ret = callJava(a,b,c,d);
+ state = RUNNING;
+ return ret;
+ }
+
+ private int sys_pause() {
+ state = PAUSED;
+ return 0;
+ }
+
+ private int sys_getpagesize() { return TOTAL_PAGES == 1 ? 4096 : PAGE_SIZE; }
+
+ private int sys_isatty(int fdn) {
+ if(fdn < 0 || fdn >= OPEN_MAX) return -EBADFD;
+ if(fds[fdn] == null) return -EBADFD;
+ return fds[fdn].isatty() ? 1 : 0;
+ }
+
+
+ /** Hook for subclasses to do something when the process exits (MUST set state = DONE) */
+ protected void _exit() { state = DONE; }
+ private int sys_exit(int status) {
+ exitStatus = status;
+ for(int i=0;i<fds.length;i++) if(fds[i] != null) sys_close(i);
+ _exit();
+ return 0;
+ }
+
+ private int sys_fcntl(int fdn, int cmd, int arg) {
+ final int F_DUPFD = 0;
+ final int F_GETFL = 3;
+ int i;
+
+ if(fdn < 0 || fdn >= OPEN_MAX) return -EBADFD;
+ if(fds[fdn] == null) return -EBADFD;
+ FD fd = fds[fdn];
+
+ switch(cmd) {
+ case F_DUPFD:
+ if(arg < 0 || arg >= OPEN_MAX) return -EINVAL;
+ for(i=arg;i<OPEN_MAX;i++) if(fds[i]==null) break;
+ if(i==OPEN_MAX) return -EMFILE;
+ fds[i] = fd.dup();
+ return 0;
+ case F_GETFL:
+ int flags = 0;
+ if(fd.writable() && fd.readable()) flags = 2;
+ else if(fd.writable()) flags = 1;
+ return flags;
+ default:
+ System.err.println("WARNING: Unknown fcntl command: " + cmd);
+ return -ENOSYS;
+ }
+ }
+
+ /** The syscall dispatcher.
+ The should be called by subclasses when the syscall instruction is invoked.
+ <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
+ the contenst of A0, A1, A2, and A3. The call MAY change the state
+ @see Runtime#state state */
+ protected int syscall(int syscall, int a, int b, int c, int d) {
+ switch(syscall) {
+ case SYS_null: return 0;
+ case SYS_exit: return sys_exit(a);
+ case SYS_pause: return sys_pause();
+ case SYS_write: return sys_write(a,b,c);
+ case SYS_fstat: return sys_fstat(a,b);
+ case SYS_sbrk: return sbrk(a);
+ case SYS_open: return sys_open(a,b,c);
+ case SYS_close: return sys_close(a);
+ case SYS_read: return sys_read(a,b,c);
+ case SYS_lseek: return sys_lseek(a,b,c);
+ case SYS_getpid: return sys_getpid();
+ case SYS_calljava: return sys_calljava(a,b,c,d);
+ case SYS_gettimeofday: return sys_gettimeofday(a,b);
+ case SYS_sleep: return sys_sleep(a);
+ case SYS_times: return sys_times(a);
+ case SYS_getpagesize: return sys_getpagesize();
+ case SYS_isatty: return sys_isatty(a);
+ case SYS_fcntl: return sys_fcntl(a,b,c);
+ case SYS_sysconf: return sys_sysconf(a);
+
+ case SYS_kill:
+ case SYS_fork:
+ case SYS_pipe:
+ case SYS_dup2:
+ case SYS_waitpid:
+ case SYS_stat:
+ case SYS_mkdir:
+ case SYS_getcwd:
+ case SYS_chdir:
+ System.err.println("Attempted to use a UnixRuntime syscall in Runtime (" + syscall + ")");
+ return -ENOSYS;
+ default:
+ System.err.println("Attempted to use unknown syscall: " + syscall);
+ return -ENOSYS;
+ }
+ }
+
+ public int xmalloc(int size) { int p=malloc(size); if(p==0) throw new RuntimeException("malloc() failed"); return p; }
+ public int xrealloc(int addr,int newsize) { int p=realloc(addr,newsize); if(p==0) throw new RuntimeException("realloc() failed"); return p; }
+ public int realloc(int addr, int newsize) { try { return call("realloc",addr,newsize); } catch(CallException e) { return 0; } }
+ public int malloc(int size) { try { return call("malloc",size); } catch(CallException e) { return 0; } }
+ public void free(int p) { try { if(p!=0) call("free",p); } catch(CallException e) { /*noop*/ } }
+
+ /** Helper function to create a cstring in main memory */
+ public int strdup(String s) {
+ byte[] a;
+ if(s == null) s = "(null)";
+ byte[] a2 = getBytes(s);
+ a = new byte[a2.length+1];
+ System.arraycopy(a2,0,a,0,a2.length);
+ int addr = malloc(a.length);
+ if(addr == 0) return 0;
+ try {
+ copyout(a,addr,a.length);
+ } catch(FaultException e) {
+ free(addr);
+ return 0;
+ }
+ return addr;
+ }
+
+ /** Helper function to read a cstring from main memory */
+ public String cstring(int addr) throws ReadFaultException {
+ StringBuffer sb = new StringBuffer();
+ for(;;) {
+ int word = memRead(addr&~3);
+ switch(addr&3) {
+ case 0: if(((word>>>24)&0xff)==0) return sb.toString(); sb.append((char)((word>>>24)&0xff)); addr++;
+ case 1: if(((word>>>16)&0xff)==0) return sb.toString(); sb.append((char)((word>>>16)&0xff)); addr++;
+ case 2: if(((word>>> 8)&0xff)==0) return sb.toString(); sb.append((char)((word>>> 8)&0xff)); addr++;
+ case 3: if(((word>>> 0)&0xff)==0) return sb.toString(); sb.append((char)((word>>> 0)&0xff)); addr++;
+ }
+ }
+ }
+
+ /** File Descriptor class */
+ public static abstract class FD {
+ private int refCount = 1;
+
+ /** returns true if the fd is readable */
+ public boolean readable() { return false; }
+ /** returns true if the fd is writable */
+ public boolean writable() { return false; }
+
+ /** Read some bytes. Should return the number of bytes read, 0 on EOF, or throw an IOException on error */
+ public int read(byte[] a, int off, int length) throws IOException { throw new IOException("no definition"); }
+ /** Write. Should return the number of bytes written or throw an IOException on error */
+ public int write(byte[] a, int off, int length) throws IOException { throw new IOException("no definition"); }
+
+ /** Seek in the filedescriptor. Whence is SEEK_SET, SEEK_CUR, or SEEK_END. Should return -1 on error or the new position. */
+ public int seek(int n, int whence) throws IOException { return -1; }
+
+ /** Should return true if this is a tty */
+ public boolean isatty() { return false; }
+
+ private FStat cachedFStat = null;
+ public final FStat fstat() {
+ if(cachedFStat == null) cachedFStat = _fstat();
+ return cachedFStat;
+ }
+
+ protected abstract FStat _fstat();
+
+ /** Closes the fd */
+ public final void close() { if(--refCount==0) _close(); }
+ protected void _close() { /* noop*/ }
+
+ FD dup() { refCount++; return this; }
+ }
+
+ /** FileDescriptor class for normal files */
+ public abstract static class SeekableFD extends FD {
+ private final int flags;
+ private final SeekableData data;
+ public boolean readable() { return (flags&3) != WR_ONLY; }
+ public boolean writable() { return (flags&3) != RD_ONLY; }
+
+ SeekableFD(SeekableData data, int flags) { this.data = data; this.flags = flags; }
+
+ protected abstract FStat _fstat();
+
+ public int seek(int n, int whence) throws IOException {
+ switch(whence) {
+ case SEEK_SET: break;
+ case SEEK_CUR: n += data.pos(); break;
+ case SEEK_END: n += data.length(); break;
+ default: return -1;
+ }
+ data.seek(n);
+ return n;
+ }
+
+ public int write(byte[] a, int off, int length) throws IOException {
+ // NOTE: There is race condition here but we can't fix it in pure java
+ if((flags&O_APPEND) != 0) seek(0,SEEK_END);
+ return data.write(a,off,length);
+ }
+
+ public int read(byte[] a, int off, int length) throws IOException {
+ int n = data.read(a,off,length);
+ return n < 0 ? 0 : n;
+ }
+
+ protected void _close() { try { data.close(); } catch(IOException e) { /*ignore*/ } }
+ }
+
+ public static class OutputStreamFD extends FD {
+ private OutputStream os;
+ public boolean writable() { return true; }
+ public OutputStreamFD(OutputStream os) { this.os = os; }
+ public int write(byte[] a, int off, int length) throws IOException { os.write(a,off,length); return length; }
+ public void _close() { try { os.close(); } catch(IOException e) { /*ignore*/ } }
+ public FStat _fstat() { return new FStat(); }
+ }
+
+ public static class InputStreamFD extends FD {
+ private InputStream is;
+ public boolean readable() { return true; }
+ public InputStreamFD(InputStream is) { this.is = is; }
+ public int read(byte[] a, int off, int length) throws IOException { int n = is.read(a,off,length); return n < 0 ? 0 : n; }
+ public void _close() { try { is.close(); } catch(IOException e) { /*ignore*/ } }
+ public FStat _fstat() { return new FStat(); }
+ }
+
+ protected static class StdinFD extends InputStreamFD {
+ public StdinFD(InputStream is) { super(is); }
+ public void _close() { /* noop */ }
+ public FStat _fstat() { return new FStat() { public int type() { return S_IFCHR; } }; }
+ public boolean isatty() { return true; }
+ }
+ protected static class StdoutFD extends OutputStreamFD {
+ public StdoutFD(OutputStream os) { super(os); }
+ public void _close() { /* noop */ }
+ public FStat _fstat() { return new FStat() { public int type() { return S_IFCHR; } }; }
+ public boolean isatty() { return true; }
+ }
+
+ public static class FStat {
+ public static final int S_IFIFO = 0010000;
+ public static final int S_IFCHR = 0020000;
+ public static final int S_IFDIR = 0040000;
+ public static final int S_IFREG = 0100000;
+
+ public int dev() { return -1; }
+ // FEATURE: inode numbers are calculated inconsistently throught the runtime
+ public int inode() { return hashCode() & 0xfffff; }
+ public int mode() { return 0; }
+ public int type() { return S_IFIFO; }
+ public int nlink() { return 0; }
+ public int uid() { return 0; }
+ public int gid() { return 0; }
+ public int size() { return 0; }
+ public int atime() { return 0; }
+ public int mtime() { return 0; }
+ public int ctime() { return 0; }
+ public int blksize() { return 512; }
+ public int blocks() { return (size()+blksize()-1)/blksize(); }
+ }
+
+ protected static class HostFStat extends FStat {
+ private final File f;
+ private final boolean executable;
+ public HostFStat(File f) {
+ this.f = f;
+ String name = f.getName();
+ // FEATURE: This is ugly.. maybe we should do a file(1) type check
+ executable = name.endsWith(".mips") || name.endsWith(".sh");
+ }
+ public int dev() { return 1; }
+ public int inode() { return f.getName().hashCode() & 0xffff; }
+ public int type() { return f.isDirectory() ? S_IFDIR : S_IFREG; }
+ public int nlink() { return 1; }
+ public int mode() {
+ int mode = 0;
+ boolean canread = f.canRead();
+ if(canread && (executable || f.isDirectory())) mode |= 0111;
+ if(canread) mode |= 0444;
+ if(f.canWrite()) mode |= 0222;
+ return mode;
+ }
+ public int size() { return (int) f.length(); }
+ public int mtime() { return (int)(f.lastModified()/1000); }
+ }
+
+ // Exceptions
+ public class ReadFaultException extends FaultException {
+ public ReadFaultException(int addr) { super(addr); }
+ }
+ public class WriteFaultException extends FaultException {
+ public WriteFaultException(int addr) { super(addr); }
+ }
+ public abstract class FaultException extends ExecutionException {
+ public int addr;
+ public FaultException(int addr) { super("fault at: " + toHex(addr)); this.addr = addr; }
+ }
+ public static class ExecutionException extends Exception {
+ private String message = "(null)";
+ private String location = "(unknown)";
+ public ExecutionException() { /* noop */ }
+ public ExecutionException(String s) { if(s != null) message = s; }
+ void setLocation(String s) { location = s == null ? "(unknown)" : s; }
+ public final String getMessage() { return message + " at " + location; }
+ }
+ public static class CallException extends Exception {
+ public CallException(String s) { super(s); }
+ }
+
+ protected static class ErrnoException extends IOException {
+ public int errno;
+ public ErrnoException(int errno) { super("Errno: " + errno); this.errno = errno; }
+ }
+
+ // CPU State
+ protected static class CPUState {
+ public CPUState() { /* noop */ }
+ /* GPRs */
+ public int[] r = new int[32];
+ /* Floating point regs */
+ public int[] f = new int[32];
+ public int hi, lo;
+ public int fcsr;
+ public int pc;
+ }
+
+ // Null pointer check helper function
+ protected final void nullPointerCheck(int addr) throws ExecutionException {
+ if(TOTAL_PAGES==1 ? addr < 65536 : (addr>>>PAGE_SHIFT) < 16)
+ throw new ExecutionException("Attempted to dereference a null pointer " + toHex(addr));
+ }
+
+ // Utility functions
+ private byte[] byteBuf(int size) {
+ if(_byteBuf==null) _byteBuf = new byte[size];
+ else if(_byteBuf.length < size)
+ _byteBuf = new byte[min(max(_byteBuf.length*2,size),MAX_CHUNK)];
+ return _byteBuf;
+ }
+
+ protected static String getSystemProperty(String key) {
+ try {
+ return System.getProperty(key);
+ } catch(SecurityException e) {
+ return null;
+ }
+ }
+
+ /** Decode an packed string.. FEATURE: document this better */
+ protected static final int[] decodeData(String s, int words) {
+ if(s.length() % 8 != 0) throw new IllegalArgumentException("string length must be a multiple of 8");
+ if((s.length() / 8) * 7 < words*4) throw new IllegalArgumentException("string isn't big enough");
+ int[] buf = new int[words];
+ int prev = 0, left=0;
+ for(int i=0,n=0;n<words;i+=8) {
+ long l = 0;
+ for(int j=0;j<8;j++) { l <<= 7; l |= s.charAt(i+j) & 0x7f; }
+ if(left > 0) buf[n++] = prev | (int)(l>>>(56-left));
+ if(n < words) buf[n++] = (int) (l >>> (24-left));
+ left = (left + 8) & 0x1f;
+ prev = (int)(l << left);
+ }
+ return buf;
+ }
+
+ protected static byte[] getBytes(String s) {
+ try {
+ return s.getBytes("ISO-8859-1");
+ } catch(UnsupportedEncodingException e) {
+ return null; // should never happen
+ }
+ }
+
+ protected final static String toHex(int n) { return "0x" + Long.toString(n & 0xffffffffL, 16); }
+ protected final static int min(int a, int b) { return a < b ? a : b; }
+ protected final static int max(int a, int b) { return a > b ? a : b; }
+}
projects / nestedvm.git / blobdiff