ARM codegen: Add disassembler, implement return

This program works:

    main() { return 42; }

The disassembler was borrowed from codeflinger, and just modified enough to compile
under C++ without warnings.

Implemented gsym
Implemented a hack verison of li, only works for -256..255
Implemented gjmp
diff --git a/libacc/Android.mk b/libacc/Android.mk
index 30f777a..c3207cc 100644
--- a/libacc/Android.mk
+++ b/libacc/Android.mk
@@ -6,6 +6,7 @@
 #
 
 LOCAL_MODULE:= acc
-LOCAL_SRC_FILES := acc.cpp
+LOCAL_SRC_FILES := acc.cpp disassem.cpp
+LOCAL_MODULE_TAGS := tests
 
 include $(BUILD_EXECUTABLE)
diff --git a/libacc/acc.cpp b/libacc/acc.cpp
index 0cc1a0f..04994e2 100644
--- a/libacc/acc.cpp
+++ b/libacc/acc.cpp
@@ -31,6 +31,8 @@
 #include <unistd.h>
 #endif
 
+#include "disassem.h"
+
 namespace acc {
 
 class compiler {
@@ -178,6 +180,8 @@
 
         virtual void adjustStackAfterCall(int l) = 0;
 
+        virtual int disassemble(FILE* out) = 0;
+
         /* output a symbol and patch all calls to it */
         virtual void gsym(int t) {
             pCodeBuf->gsym(t);
@@ -185,15 +189,20 @@
 
         virtual int finishCompile() {
 #if defined(__arm__)
-        const long base = long(pCodeBuf->getBase());
-        const long curr = base + long(pCodeBuf->getSize());
-        int err = cacheflush(base, curr, 0);
-        return err;
+            const long base = long(pCodeBuf->getBase());
+            const long curr = base + long(pCodeBuf->getSize());
+            int err = cacheflush(base, curr, 0);
+            return err;
 #else
-        return 0;
+            return 0;
 #endif
         }
 
+        /**
+         * Adjust relative branches by this amount.
+         */
+        virtual int jumpOffset() = 0;
+
     protected:
         void o(int n) {
             pCodeBuf->o(n);
@@ -217,6 +226,10 @@
             return pCodeBuf->oad(n,t);
         }
 
+        int getBase() {
+            return (int) pCodeBuf->getBase();
+        }
+
         int getPC() {
             return pCodeBuf->getPC();
         }
@@ -271,12 +284,19 @@
         /* load immediate value */
         virtual void li(int t) {
             fprintf(stderr, "li(%d);\n", t);
-            oad(0xb8, t); /* mov $xx, %eax */
+            if (t >= 0 && t < 255) {
+                 o4(0xE3A00000 + t); // E3A00000 mov    r0, #0
+            } else if (t >= -256 && t < 0) {
+                // mvn means move constant ^ ~0
+                o4(0xE3E00001 - t); // E3E00000         mvn    r0, #0
+            } else {
+                error("immediate constant out of range -256..255: %d", t);
+            }
         }
 
         virtual int gjmp(int t) {
             fprintf(stderr, "gjmp(%d);\n", t);
-            return psym(0xe9, t);
+            return o4(0xEA000000 + encodeAddress(t));
         }
 
         /* l = 0: je, l == 1: jne */
@@ -397,7 +417,86 @@
             oad(0xc481, l); /* add $xxx, %esp */
         }
 
+        virtual int jumpOffset() {
+            return 4;
+        }
+
+        /* output a symbol and patch all calls to it */
+        virtual void gsym(int t) {
+            fprintf(stderr, "gsym(0x%x)\n", t);
+            int n;
+            int base = getBase();
+            int pc = getPC();
+            fprintf(stderr, "pc = 0x%x\n", pc);
+            while (t) {
+                int data = * (int*) t;
+                int decodedOffset = ((BRANCH_REL_ADDRESS_MASK & data) << 2);
+                if (decodedOffset == 0) {
+                    n = 0;
+                } else {
+                    n = base + decodedOffset; /* next value */
+                }
+                *(int *) t = (data & ~BRANCH_REL_ADDRESS_MASK)
+                    | encodeRelAddress(pc - t - 8);
+                t = n;
+            }
+        }
+
+        virtual int disassemble(FILE* out) {
+               disasmOut = out;
+            disasm_interface_t  di;
+            di.di_readword = disassemble_readword;
+            di.di_printaddr = disassemble_printaddr;
+            di.di_printf = disassemble_printf;
+
+            int base = getBase();
+            int pc = getPC();
+            for(int i = base; i < pc; i += 4) {
+                fprintf(out, "%08x: %08x  ", i, *(int*) i);
+                ::disasm(&di, i, 0);
+            }
+            return 0;
+        }
     private:
+        static FILE* disasmOut;
+
+        static u_int
+        disassemble_readword(u_int address)
+        {
+            return(*((u_int *)address));
+        }
+
+        static void
+        disassemble_printaddr(u_int address)
+        {
+            fprintf(disasmOut, "0x%08x", address);
+        }
+
+        static void
+        disassemble_printf(const char *fmt, ...) {
+            va_list ap;
+            va_start(ap, fmt);
+            vfprintf(disasmOut, fmt, ap);
+            va_end(ap);
+        }
+
+        static const int BRANCH_REL_ADDRESS_MASK = 0x00ffffff;
+
+        /** Encode a relative address that might also be
+         * a label.
+         */
+        int encodeAddress(int value) {
+            int base = getBase();
+            if (value >= base && value <= getPC() ) {
+                // This is a label, encode it relative to the base.
+                value = value - base;
+            }
+            return encodeRelAddress(value);
+        }
+
+        int encodeRelAddress(int value) {
+            return BRANCH_REL_ADDRESS_MASK & (value >> 2);
+        }
 
         void error(const char* fmt,...) {
             va_list ap;
@@ -522,6 +621,14 @@
             oad(0xc481, l); /* add $xxx, %esp */
         }
 
+        virtual int jumpOffset() {
+            return 5;
+        }
+
+        virtual int disassemble(FILE* out) {
+            return 1;
+        }
+
     private:
         static const int operatorHelper[];
 
@@ -896,7 +1003,7 @@
                 pGen->callIndirect(l);
                 l = l + 4;
             } else {
-                pGen->callRelative(n - codeBuf.getPC() - 5); /* call xxx */
+                pGen->callRelative(n - codeBuf.getPC() - pGen->jumpOffset()); /* call xxx */
             }
             if (l)
                 pGen->adjustStackAfterCall(l);
@@ -935,7 +1042,7 @@
             if (a && l > 8) {
                 a = pGen->gtst(t == OP_LOGICAL_OR, a);
                 pGen->li(t != OP_LOGICAL_OR);
-                pGen->gjmp(5); /* jmp $ + 5 */
+                pGen->gjmp(5); /* jmp $ + 5 (sizeof li, FIXME for ARM) */
                 pGen->gsym(a);
                 pGen->li(t == OP_LOGICAL_OR);
             }
@@ -974,7 +1081,7 @@
             next();
             skip('(');
             if (t == TOK_WHILE) {
-                n = codeBuf.getPC();
+                n = codeBuf.getPC(); // top of loop, target of "next" iteration
                 a = test_expr();
             } else {
                 if (tok != ';')
@@ -988,14 +1095,14 @@
                 if (tok != ')') {
                     t = pGen->gjmp(0);
                     expr();
-                    pGen->gjmp(n - codeBuf.getPC() - 5);
+                    pGen->gjmp(n - codeBuf.getPC() - pGen->jumpOffset());
                     pGen->gsym(t);
                     n = t + 4;
                 }
             }
             skip(')');
             block((int) &a);
-            pGen->gjmp(n - codeBuf.getPC() - 5); /* jmp */
+            pGen->gjmp(n - codeBuf.getPC() - pGen->jumpOffset()); /* jmp */
             pGen->gsym(a);
         } else if (tok == '{') {
             next();
@@ -1179,6 +1286,10 @@
         return 0;
     }
 
+    int disassemble(FILE* out) {
+        return pGen->disassemble(out);
+    }
+
 };
 
 const char* compiler::operatorChars =
@@ -1192,6 +1303,8 @@
             2, 2 /* ~ ! */
             };
 
+FILE* compiler::ARMCodeGenerator::disasmOut;
+
 const int compiler::X86CodeGenerator::operatorHelper[] = {
         0x1,     // ++
         0xff,    // --
@@ -1226,6 +1339,7 @@
 
 int main(int argc, char** argv) {
     bool doDump = false;
+    bool doDisassemble = false;
     const char* inFile = NULL;
     const char* outFile = NULL;
     const char* architecture = "arm";
@@ -1251,6 +1365,9 @@
                 outFile = argv[i + 1];
                 i += 1;
                 break;
+            case 'S':
+                doDisassemble = true;
+                break;
             default:
                 fprintf(stderr, "Unrecognized flag %s\n", arg);
                 return 3;
@@ -1281,6 +1398,9 @@
         fprintf(stderr, "Compile failed: %d\n", compileResult);
         return 6;
     }
+    if (doDisassemble) {
+        compiler.disassemble(stderr);
+    }
     if (doDump) {
         FILE* save = fopen(outFile, "w");
         if (!save) {
diff --git a/libacc/armreg.h b/libacc/armreg.h
new file mode 100644
index 0000000..fde81ba
--- /dev/null
+++ b/libacc/armreg.h
@@ -0,0 +1,300 @@
+/*	$NetBSD: armreg.h,v 1.28 2003/10/31 16:30:15 scw Exp $	*/
+
+/*-
+ * Copyright (c) 1998, 2001 Ben Harris
+ * Copyright (c) 1994-1996 Mark Brinicombe.
+ * Copyright (c) 1994 Brini.
+ * All rights reserved.
+ *
+ * This code is derived from software written for Brini by Mark Brinicombe
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by Brini.
+ * 4. The name of the company nor the name of the author may be used to
+ *    endorse or promote products derived from this software without specific
+ *    prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD: /repoman/r/ncvs/src/sys/arm/include/armreg.h,v 1.3 2005/11/21 19:06:25 cognet Exp $
+ */
+
+#ifndef MACHINE_ARMREG_H
+#define MACHINE_ARMREG_H
+#define INSN_SIZE	4
+#define INSN_COND_MASK	0xf0000000	/* Condition mask */
+#define PSR_MODE        0x0000001f      /* mode mask */
+#define PSR_USR26_MODE  0x00000000
+#define PSR_FIQ26_MODE  0x00000001
+#define PSR_IRQ26_MODE  0x00000002
+#define PSR_SVC26_MODE  0x00000003
+#define PSR_USR32_MODE  0x00000010
+#define PSR_FIQ32_MODE  0x00000011
+#define PSR_IRQ32_MODE  0x00000012
+#define PSR_SVC32_MODE  0x00000013
+#define PSR_ABT32_MODE  0x00000017
+#define PSR_UND32_MODE  0x0000001b
+#define PSR_SYS32_MODE  0x0000001f
+#define PSR_32_MODE     0x00000010
+#define PSR_FLAGS	0xf0000000    /* flags */
+
+#define PSR_C_bit (1 << 29)       /* carry */
+
+/* The high-order byte is always the implementor */
+#define CPU_ID_IMPLEMENTOR_MASK	0xff000000
+#define CPU_ID_ARM_LTD		0x41000000 /* 'A' */
+#define CPU_ID_DEC		0x44000000 /* 'D' */
+#define CPU_ID_INTEL		0x69000000 /* 'i' */
+#define	CPU_ID_TI		0x54000000 /* 'T' */
+
+/* How to decide what format the CPUID is in. */
+#define CPU_ID_ISOLD(x)		(((x) & 0x0000f000) == 0x00000000)
+#define CPU_ID_IS7(x)		(((x) & 0x0000f000) == 0x00007000)
+#define CPU_ID_ISNEW(x)		(!CPU_ID_ISOLD(x) && !CPU_ID_IS7(x))
+
+/* On ARM3 and ARM6, this byte holds the foundry ID. */
+#define CPU_ID_FOUNDRY_MASK	0x00ff0000
+#define CPU_ID_FOUNDRY_VLSI	0x00560000
+
+/* On ARM7 it holds the architecture and variant (sub-model) */
+#define CPU_ID_7ARCH_MASK	0x00800000
+#define CPU_ID_7ARCH_V3		0x00000000
+#define CPU_ID_7ARCH_V4T	0x00800000
+#define CPU_ID_7VARIANT_MASK	0x007f0000
+
+/* On more recent ARMs, it does the same, but in a different format */
+#define CPU_ID_ARCH_MASK	0x000f0000
+#define CPU_ID_ARCH_V3		0x00000000
+#define CPU_ID_ARCH_V4		0x00010000
+#define CPU_ID_ARCH_V4T		0x00020000
+#define CPU_ID_ARCH_V5		0x00030000
+#define CPU_ID_ARCH_V5T		0x00040000
+#define CPU_ID_ARCH_V5TE	0x00050000
+#define CPU_ID_VARIANT_MASK	0x00f00000
+
+/* Next three nybbles are part number */
+#define CPU_ID_PARTNO_MASK	0x0000fff0
+
+/* Intel XScale has sub fields in part number */
+#define CPU_ID_XSCALE_COREGEN_MASK	0x0000e000 /* core generation */
+#define CPU_ID_XSCALE_COREREV_MASK	0x00001c00 /* core revision */
+#define CPU_ID_XSCALE_PRODUCT_MASK	0x000003f0 /* product number */
+
+/* And finally, the revision number. */
+#define CPU_ID_REVISION_MASK	0x0000000f
+
+/* Individual CPUs are probably best IDed by everything but the revision. */
+#define CPU_ID_CPU_MASK		0xfffffff0
+
+/* Fake CPU IDs for ARMs without CP15 */
+#define CPU_ID_ARM2		0x41560200
+#define CPU_ID_ARM250		0x41560250
+
+/* Pre-ARM7 CPUs -- [15:12] == 0 */
+#define CPU_ID_ARM3		0x41560300
+#define CPU_ID_ARM600		0x41560600
+#define CPU_ID_ARM610		0x41560610
+#define CPU_ID_ARM620		0x41560620
+
+/* ARM7 CPUs -- [15:12] == 7 */
+#define CPU_ID_ARM700		0x41007000 /* XXX This is a guess. */
+#define CPU_ID_ARM710		0x41007100
+#define CPU_ID_ARM7500		0x41027100 /* XXX This is a guess. */
+#define CPU_ID_ARM710A		0x41047100 /* inc ARM7100 */
+#define CPU_ID_ARM7500FE	0x41077100
+#define CPU_ID_ARM710T		0x41807100
+#define CPU_ID_ARM720T		0x41807200
+#define CPU_ID_ARM740T8K	0x41807400 /* XXX no MMU, 8KB cache */
+#define CPU_ID_ARM740T4K	0x41817400 /* XXX no MMU, 4KB cache */
+
+/* Post-ARM7 CPUs */
+#define CPU_ID_ARM810		0x41018100
+#define CPU_ID_ARM920T		0x41129200
+#define CPU_ID_ARM920T_ALT	0x41009200
+#define CPU_ID_ARM922T		0x41029220
+#define CPU_ID_ARM940T		0x41029400 /* XXX no MMU */
+#define CPU_ID_ARM946ES		0x41049460 /* XXX no MMU */
+#define	CPU_ID_ARM966ES		0x41049660 /* XXX no MMU */
+#define	CPU_ID_ARM966ESR1	0x41059660 /* XXX no MMU */
+#define CPU_ID_ARM1020E		0x4115a200 /* (AKA arm10 rev 1) */
+#define CPU_ID_ARM1022ES	0x4105a220
+#define CPU_ID_SA110		0x4401a100
+#define CPU_ID_SA1100		0x4401a110
+#define	CPU_ID_TI925T		0x54029250
+#define CPU_ID_SA1110		0x6901b110
+#define CPU_ID_IXP1200		0x6901c120
+#define CPU_ID_80200		0x69052000
+#define CPU_ID_PXA250    	0x69052100 /* sans core revision */
+#define CPU_ID_PXA210    	0x69052120
+#define CPU_ID_PXA250A		0x69052100 /* 1st version Core */
+#define CPU_ID_PXA210A		0x69052120 /* 1st version Core */
+#define CPU_ID_PXA250B		0x69052900 /* 3rd version Core */
+#define CPU_ID_PXA210B		0x69052920 /* 3rd version Core */
+#define CPU_ID_PXA250C		0x69052d00 /* 4th version Core */
+#define CPU_ID_PXA210C		0x69052d20 /* 4th version Core */
+#define	CPU_ID_80321_400	0x69052420
+#define	CPU_ID_80321_600	0x69052430
+#define	CPU_ID_80321_400_B0	0x69052c20
+#define	CPU_ID_80321_600_B0	0x69052c30
+#define	CPU_ID_IXP425_533	0x690541c0
+#define	CPU_ID_IXP425_400	0x690541d0
+#define	CPU_ID_IXP425_266	0x690541f0
+
+/* ARM3-specific coprocessor 15 registers */
+#define ARM3_CP15_FLUSH		1
+#define ARM3_CP15_CONTROL	2
+#define ARM3_CP15_CACHEABLE	3
+#define ARM3_CP15_UPDATEABLE	4
+#define ARM3_CP15_DISRUPTIVE	5	
+
+/* ARM3 Control register bits */
+#define ARM3_CTL_CACHE_ON	0x00000001
+#define ARM3_CTL_SHARED		0x00000002
+#define ARM3_CTL_MONITOR	0x00000004
+
+/*
+ * Post-ARM3 CP15 registers:
+ *
+ *	1	Control register
+ *
+ *	2	Translation Table Base
+ *
+ *	3	Domain Access Control
+ *
+ *	4	Reserved
+ *
+ *	5	Fault Status
+ *
+ *	6	Fault Address
+ *
+ *	7	Cache/write-buffer Control
+ *
+ *	8	TLB Control
+ *
+ *	9	Cache Lockdown
+ *
+ *	10	TLB Lockdown
+ *
+ *	11	Reserved
+ *
+ *	12	Reserved
+ *
+ *	13	Process ID (for FCSE)
+ *
+ *	14	Reserved
+ *
+ *	15	Implementation Dependent
+ */
+
+/* Some of the definitions below need cleaning up for V3/V4 architectures */
+
+/* CPU control register (CP15 register 1) */
+#define CPU_CONTROL_MMU_ENABLE	0x00000001 /* M: MMU/Protection unit enable */
+#define CPU_CONTROL_AFLT_ENABLE	0x00000002 /* A: Alignment fault enable */
+#define CPU_CONTROL_DC_ENABLE	0x00000004 /* C: IDC/DC enable */
+#define CPU_CONTROL_WBUF_ENABLE 0x00000008 /* W: Write buffer enable */
+#define CPU_CONTROL_32BP_ENABLE 0x00000010 /* P: 32-bit exception handlers */
+#define CPU_CONTROL_32BD_ENABLE 0x00000020 /* D: 32-bit addressing */
+#define CPU_CONTROL_LABT_ENABLE 0x00000040 /* L: Late abort enable */
+#define CPU_CONTROL_BEND_ENABLE 0x00000080 /* B: Big-endian mode */
+#define CPU_CONTROL_SYST_ENABLE 0x00000100 /* S: System protection bit */
+#define CPU_CONTROL_ROM_ENABLE	0x00000200 /* R: ROM protection bit */
+#define CPU_CONTROL_CPCLK	0x00000400 /* F: Implementation defined */
+#define CPU_CONTROL_BPRD_ENABLE 0x00000800 /* Z: Branch prediction enable */
+#define CPU_CONTROL_IC_ENABLE   0x00001000 /* I: IC enable */
+#define CPU_CONTROL_VECRELOC	0x00002000 /* V: Vector relocation */
+#define CPU_CONTROL_ROUNDROBIN	0x00004000 /* RR: Predictable replacement */
+#define CPU_CONTROL_V4COMPAT	0x00008000 /* L4: ARMv4 compat LDR R15 etc */
+
+#define CPU_CONTROL_IDC_ENABLE	CPU_CONTROL_DC_ENABLE
+
+/* XScale Auxillary Control Register (CP15 register 1, opcode2 1) */
+#define	XSCALE_AUXCTL_K		0x00000001 /* dis. write buffer coalescing */
+#define	XSCALE_AUXCTL_P		0x00000002 /* ECC protect page table access */
+#define	XSCALE_AUXCTL_MD_WB_RA	0x00000000 /* mini-D$ wb, read-allocate */
+#define	XSCALE_AUXCTL_MD_WB_RWA	0x00000010 /* mini-D$ wb, read/write-allocate */
+#define	XSCALE_AUXCTL_MD_WT	0x00000020 /* mini-D$ wt, read-allocate */
+#define	XSCALE_AUXCTL_MD_MASK	0x00000030
+
+/* Cache type register definitions */
+#define	CPU_CT_ISIZE(x)		((x) & 0xfff)		/* I$ info */
+#define	CPU_CT_DSIZE(x)		(((x) >> 12) & 0xfff)	/* D$ info */
+#define	CPU_CT_S		(1U << 24)		/* split cache */
+#define	CPU_CT_CTYPE(x)		(((x) >> 25) & 0xf)	/* cache type */
+
+#define	CPU_CT_CTYPE_WT		0	/* write-through */
+#define	CPU_CT_CTYPE_WB1	1	/* write-back, clean w/ read */
+#define	CPU_CT_CTYPE_WB2	2	/* w/b, clean w/ cp15,7 */
+#define	CPU_CT_CTYPE_WB6	6	/* w/b, cp15,7, lockdown fmt A */
+#define	CPU_CT_CTYPE_WB7	7	/* w/b, cp15,7, lockdown fmt B */
+
+#define	CPU_CT_xSIZE_LEN(x)	((x) & 0x3)		/* line size */
+#define	CPU_CT_xSIZE_M		(1U << 2)		/* multiplier */
+#define	CPU_CT_xSIZE_ASSOC(x)	(((x) >> 3) & 0x7)	/* associativity */
+#define	CPU_CT_xSIZE_SIZE(x)	(((x) >> 6) & 0x7)	/* size */
+
+/* Fault status register definitions */
+
+#define FAULT_TYPE_MASK 0x0f
+#define FAULT_USER      0x10
+
+#define FAULT_WRTBUF_0  0x00 /* Vector Exception */
+#define FAULT_WRTBUF_1  0x02 /* Terminal Exception */
+#define FAULT_BUSERR_0  0x04 /* External Abort on Linefetch -- Section */
+#define FAULT_BUSERR_1  0x06 /* External Abort on Linefetch -- Page */
+#define FAULT_BUSERR_2  0x08 /* External Abort on Non-linefetch -- Section */
+#define FAULT_BUSERR_3  0x0a /* External Abort on Non-linefetch -- Page */
+#define FAULT_BUSTRNL1  0x0c /* External abort on Translation -- Level 1 */
+#define FAULT_BUSTRNL2  0x0e /* External abort on Translation -- Level 2 */
+#define FAULT_ALIGN_0   0x01 /* Alignment */
+#define FAULT_ALIGN_1   0x03 /* Alignment */
+#define FAULT_TRANS_S   0x05 /* Translation -- Section */
+#define FAULT_TRANS_P   0x07 /* Translation -- Page */
+#define FAULT_DOMAIN_S  0x09 /* Domain -- Section */
+#define FAULT_DOMAIN_P  0x0b /* Domain -- Page */
+#define FAULT_PERM_S    0x0d /* Permission -- Section */
+#define FAULT_PERM_P    0x0f /* Permission -- Page */
+
+#define	FAULT_IMPRECISE	0x400	/* Imprecise exception (XSCALE) */
+
+/*
+ * Address of the vector page, low and high versions.
+ */
+#define	ARM_VECTORS_LOW		0x00000000U
+#define	ARM_VECTORS_HIGH	0xffff0000U
+
+/*
+ * ARM Instructions
+ *
+ *       3 3 2 2 2                              
+ *       1 0 9 8 7                                                     0
+ *      +-------+-------------------------------------------------------+
+ *      | cond  |              instruction dependant                    |
+ *      |c c c c|                                                       |
+ *      +-------+-------------------------------------------------------+
+ */
+
+#define INSN_SIZE		4		/* Always 4 bytes */
+#define INSN_COND_MASK		0xf0000000	/* Condition mask */
+#define INSN_COND_AL		0xe0000000	/* Always condition */
+
+#endif /* !MACHINE_ARMREG_H */
diff --git a/libacc/disassem.cpp b/libacc/disassem.cpp
new file mode 100644
index 0000000..ac35342
--- /dev/null
+++ b/libacc/disassem.cpp
@@ -0,0 +1,711 @@
+/*	$NetBSD: disassem.c,v 1.14 2003/03/27 16:58:36 mycroft Exp $	*/
+
+/*-
+ * Copyright (c) 1996 Mark Brinicombe.
+ * Copyright (c) 1996 Brini.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by Brini.
+ * 4. The name of the company nor the name of the author may be used to
+ *    endorse or promote products derived from this software without specific
+ *    prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * RiscBSD kernel project
+ *
+ * db_disasm.c
+ *
+ * Kernel disassembler
+ *
+ * Created      : 10/02/96
+ *
+ * Structured after the sparc/sparc/db_disasm.c by David S. Miller &
+ * Paul Kranenburg
+ *
+ * This code is not complete. Not all instructions are disassembled.
+ */
+
+#include <sys/cdefs.h>
+//__FBSDID("$FreeBSD: /repoman/r/ncvs/src/sys/arm/arm/disassem.c,v 1.2 2005/01/05 21:58:47 imp Exp $");
+#include <sys/param.h>
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "disassem.h"
+#include "armreg.h"
+//#include <ddb/ddb.h>
+
+/*
+ * General instruction format
+ *
+ *	insn[cc][mod]	[operands]
+ *
+ * Those fields with an uppercase format code indicate that the field
+ * follows directly after the instruction before the separator i.e.
+ * they modify the instruction rather than just being an operand to
+ * the instruction. The only exception is the writeback flag which
+ * follows a operand.
+ *
+ *
+ * 2 - print Operand 2 of a data processing instruction
+ * d - destination register (bits 12-15)
+ * n - n register (bits 16-19)
+ * s - s register (bits 8-11)
+ * o - indirect register rn (bits 16-19) (used by swap)
+ * m - m register (bits 0-3)
+ * a - address operand of ldr/str instruction
+ * e - address operand of ldrh/strh instruction
+ * l - register list for ldm/stm instruction
+ * f - 1st fp operand (register) (bits 12-14)
+ * g - 2nd fp operand (register) (bits 16-18)
+ * h - 3rd fp operand (register/immediate) (bits 0-4)
+ * b - branch address
+ * t - thumb branch address (bits 24, 0-23)
+ * k - breakpoint comment (bits 0-3, 8-19)
+ * X - block transfer type
+ * Y - block transfer type (r13 base)
+ * c - comment field bits(0-23)
+ * p - saved or current status register
+ * F - PSR transfer fields
+ * D - destination-is-r15 (P) flag on TST, TEQ, CMP, CMN
+ * L - co-processor transfer size
+ * S - set status flag
+ * P - fp precision
+ * Q - fp precision (for ldf/stf)
+ * R - fp rounding
+ * v - co-processor data transfer registers + addressing mode
+ * W - writeback flag
+ * x - instruction in hex
+ * # - co-processor number
+ * y - co-processor data processing registers
+ * z - co-processor register transfer registers
+ */
+
+struct arm32_insn {
+	u_int mask;
+	u_int pattern;
+	const char* name;
+	const char* format;
+};
+
+static const struct arm32_insn arm32_i[] = {
+    { 0x0fffffff, 0x0ff00000, "imb",	"c" },		/* Before swi */
+    { 0x0fffffff, 0x0ff00001, "imbrange",	"c" },	/* Before swi */
+    { 0x0f000000, 0x0f000000, "swi",	"c" },
+    { 0xfe000000, 0xfa000000, "blx",	"t" },		/* Before b and bl */
+    { 0x0f000000, 0x0a000000, "b",	"b" },
+    { 0x0f000000, 0x0b000000, "bl",	"b" },
+    { 0x0fe000f0, 0x00000090, "mul",	"Snms" },
+    { 0x0fe000f0, 0x00200090, "mla",	"Snmsd" },
+    { 0x0fe000f0, 0x00800090, "umull",	"Sdnms" },
+    { 0x0fe000f0, 0x00c00090, "smull",	"Sdnms" },
+    { 0x0fe000f0, 0x00a00090, "umlal",	"Sdnms" },
+    { 0x0fe000f0, 0x00e00090, "smlal",	"Sdnms" },
+    { 0x0d700000, 0x04200000, "strt",	"daW" },
+    { 0x0d700000, 0x04300000, "ldrt",	"daW" },
+    { 0x0d700000, 0x04600000, "strbt",	"daW" },
+    { 0x0d700000, 0x04700000, "ldrbt",	"daW" },
+    { 0x0c500000, 0x04000000, "str",	"daW" },
+    { 0x0c500000, 0x04100000, "ldr",	"daW" },
+    { 0x0c500000, 0x04400000, "strb",	"daW" },
+    { 0x0c500000, 0x04500000, "ldrb",	"daW" },
+    { 0x0e1f0000, 0x080d0000, "stm",	"YnWl" },/* separate out r13 base */
+    { 0x0e1f0000, 0x081d0000, "ldm",	"YnWl" },/* separate out r13 base */    
+    { 0x0e100000, 0x08000000, "stm",	"XnWl" },
+    { 0x0e100000, 0x08100000, "ldm",	"XnWl" },    
+    { 0x0e1000f0, 0x00100090, "ldrb",	"deW" },
+    { 0x0e1000f0, 0x00000090, "strb",	"deW" },
+    { 0x0e1000f0, 0x001000d0, "ldrsb",	"deW" },
+    { 0x0e1000f0, 0x001000b0, "ldrh",	"deW" },
+    { 0x0e1000f0, 0x000000b0, "strh",	"deW" },
+    { 0x0e1000f0, 0x001000f0, "ldrsh",	"deW" },
+    { 0x0f200090, 0x00200090, "und",	"x" },	/* Before data processing */
+    { 0x0e1000d0, 0x000000d0, "und",	"x" },	/* Before data processing */
+    { 0x0ff00ff0, 0x01000090, "swp",	"dmo" },
+    { 0x0ff00ff0, 0x01400090, "swpb",	"dmo" },
+    { 0x0fbf0fff, 0x010f0000, "mrs",	"dp" },	/* Before data processing */
+    { 0x0fb0fff0, 0x0120f000, "msr",	"pFm" },/* Before data processing */
+    { 0x0fb0f000, 0x0320f000, "msr",	"pF2" },/* Before data processing */
+    { 0x0ffffff0, 0x012fff10, "bx",     "m" },
+    { 0x0fff0ff0, 0x016f0f10, "clz",	"dm" },
+    { 0x0ffffff0, 0x012fff30, "blx",	"m" },
+    { 0xfff000f0, 0xe1200070, "bkpt",	"k" },
+    { 0x0de00000, 0x00000000, "and",	"Sdn2" },
+    { 0x0de00000, 0x00200000, "eor",	"Sdn2" },
+    { 0x0de00000, 0x00400000, "sub",	"Sdn2" },
+    { 0x0de00000, 0x00600000, "rsb",	"Sdn2" },
+    { 0x0de00000, 0x00800000, "add",	"Sdn2" },
+    { 0x0de00000, 0x00a00000, "adc",	"Sdn2" },
+    { 0x0de00000, 0x00c00000, "sbc",	"Sdn2" },
+    { 0x0de00000, 0x00e00000, "rsc",	"Sdn2" },
+    { 0x0df00000, 0x01100000, "tst",	"Dn2" },
+    { 0x0df00000, 0x01300000, "teq",	"Dn2" },
+    { 0x0df00000, 0x01500000, "cmp",	"Dn2" },
+    { 0x0df00000, 0x01700000, "cmn",	"Dn2" },
+    { 0x0de00000, 0x01800000, "orr",	"Sdn2" },
+    { 0x0de00000, 0x01a00000, "mov",	"Sd2" },
+    { 0x0de00000, 0x01c00000, "bic",	"Sdn2" },
+    { 0x0de00000, 0x01e00000, "mvn",	"Sd2" },
+    { 0x0ff08f10, 0x0e000100, "adf",	"PRfgh" },
+    { 0x0ff08f10, 0x0e100100, "muf",	"PRfgh" },
+    { 0x0ff08f10, 0x0e200100, "suf",	"PRfgh" },
+    { 0x0ff08f10, 0x0e300100, "rsf",	"PRfgh" },
+    { 0x0ff08f10, 0x0e400100, "dvf",	"PRfgh" },
+    { 0x0ff08f10, 0x0e500100, "rdf",	"PRfgh" },
+    { 0x0ff08f10, 0x0e600100, "pow",	"PRfgh" },
+    { 0x0ff08f10, 0x0e700100, "rpw",	"PRfgh" },
+    { 0x0ff08f10, 0x0e800100, "rmf",	"PRfgh" },
+    { 0x0ff08f10, 0x0e900100, "fml",	"PRfgh" },
+    { 0x0ff08f10, 0x0ea00100, "fdv",	"PRfgh" },
+    { 0x0ff08f10, 0x0eb00100, "frd",	"PRfgh" },
+    { 0x0ff08f10, 0x0ec00100, "pol",	"PRfgh" },
+    { 0x0f008f10, 0x0e000100, "fpbop",	"PRfgh" },
+    { 0x0ff08f10, 0x0e008100, "mvf",	"PRfh" },
+    { 0x0ff08f10, 0x0e108100, "mnf",	"PRfh" },
+    { 0x0ff08f10, 0x0e208100, "abs",	"PRfh" },
+    { 0x0ff08f10, 0x0e308100, "rnd",	"PRfh" },
+    { 0x0ff08f10, 0x0e408100, "sqt",	"PRfh" },
+    { 0x0ff08f10, 0x0e508100, "log",	"PRfh" },
+    { 0x0ff08f10, 0x0e608100, "lgn",	"PRfh" },
+    { 0x0ff08f10, 0x0e708100, "exp",	"PRfh" },
+    { 0x0ff08f10, 0x0e808100, "sin",	"PRfh" },
+    { 0x0ff08f10, 0x0e908100, "cos",	"PRfh" },
+    { 0x0ff08f10, 0x0ea08100, "tan",	"PRfh" },
+    { 0x0ff08f10, 0x0eb08100, "asn",	"PRfh" },
+    { 0x0ff08f10, 0x0ec08100, "acs",	"PRfh" },
+    { 0x0ff08f10, 0x0ed08100, "atn",	"PRfh" },
+    { 0x0f008f10, 0x0e008100, "fpuop",	"PRfh" },
+    { 0x0e100f00, 0x0c000100, "stf",	"QLv" },
+    { 0x0e100f00, 0x0c100100, "ldf",	"QLv" },
+    { 0x0ff00f10, 0x0e000110, "flt",	"PRgd" },
+    { 0x0ff00f10, 0x0e100110, "fix",	"PRdh" },
+    { 0x0ff00f10, 0x0e200110, "wfs",	"d" },
+    { 0x0ff00f10, 0x0e300110, "rfs",	"d" },
+    { 0x0ff00f10, 0x0e400110, "wfc",	"d" },
+    { 0x0ff00f10, 0x0e500110, "rfc",	"d" },
+    { 0x0ff0ff10, 0x0e90f110, "cmf",	"PRgh" },
+    { 0x0ff0ff10, 0x0eb0f110, "cnf",	"PRgh" },
+    { 0x0ff0ff10, 0x0ed0f110, "cmfe",	"PRgh" },
+    { 0x0ff0ff10, 0x0ef0f110, "cnfe",	"PRgh" },
+    { 0xff100010, 0xfe000010, "mcr2",	"#z" },
+    { 0x0f100010, 0x0e000010, "mcr",	"#z" },
+    { 0xff100010, 0xfe100010, "mrc2",	"#z" },
+    { 0x0f100010, 0x0e100010, "mrc",	"#z" },
+    { 0xff000010, 0xfe000000, "cdp2",	"#y" },
+    { 0x0f000010, 0x0e000000, "cdp",	"#y" },
+    { 0xfe100090, 0xfc100000, "ldc2",	"L#v" },
+    { 0x0e100090, 0x0c100000, "ldc",	"L#v" },
+    { 0xfe100090, 0xfc000000, "stc2",	"L#v" },
+    { 0x0e100090, 0x0c000000, "stc",	"L#v" },
+    { 0xf550f000, 0xf550f000, "pld",	"ne" },
+    { 0x0ff00ff0, 0x01000050, "qaad",	"dmn" },
+    { 0x0ff00ff0, 0x01400050, "qdaad",	"dmn" },
+    { 0x0ff00ff0, 0x01600050, "qdsub",	"dmn" },
+    { 0x0ff00ff0, 0x01200050, "dsub",	"dmn" },
+    { 0x0ff000f0, 0x01000080, "smlabb",	"nmsd" },   // d & n inverted!!
+    { 0x0ff000f0, 0x010000a0, "smlatb",	"nmsd" },   // d & n inverted!!
+    { 0x0ff000f0, 0x010000c0, "smlabt",	"nmsd" },   // d & n inverted!!
+    { 0x0ff000f0, 0x010000e0, "smlatt",	"nmsd" },   // d & n inverted!!
+    { 0x0ff000f0, 0x01400080, "smlalbb","ndms" },   // d & n inverted!!
+    { 0x0ff000f0, 0x014000a0, "smlaltb","ndms" },   // d & n inverted!!
+    { 0x0ff000f0, 0x014000c0, "smlalbt","ndms" },   // d & n inverted!!
+    { 0x0ff000f0, 0x014000e0, "smlaltt","ndms" },   // d & n inverted!!
+    { 0x0ff000f0, 0x01200080, "smlawb", "nmsd" },   // d & n inverted!!
+    { 0x0ff0f0f0, 0x012000a0, "smulwb","nms" },   // d & n inverted!!
+    { 0x0ff000f0, 0x012000c0, "smlawt", "nmsd" },   // d & n inverted!!
+    { 0x0ff0f0f0, 0x012000e0, "smulwt","nms" },   // d & n inverted!!
+    { 0x0ff0f0f0, 0x01600080, "smulbb","nms" },   // d & n inverted!!
+    { 0x0ff0f0f0, 0x016000a0, "smultb","nms" },   // d & n inverted!!
+    { 0x0ff0f0f0, 0x016000c0, "smulbt","nms" },   // d & n inverted!!
+    { 0x0ff0f0f0, 0x016000e0, "smultt","nms" },   // d & n inverted!!
+    { 0x00000000, 0x00000000, NULL,	NULL }
+};
+
+static char const arm32_insn_conditions[][4] = {
+	"eq", "ne", "cs", "cc",
+	"mi", "pl", "vs", "vc",
+	"hi", "ls", "ge", "lt",
+	"gt", "le", "",   "nv"
+};
+
+static char const insn_block_transfers[][4] = {
+	"da", "ia", "db", "ib"
+};
+
+static char const insn_stack_block_transfers[][4] = {
+	"ed", "ea", "fd", "fa"
+};
+
+static char const op_shifts[][4] = {
+	"lsl", "lsr", "asr", "ror"
+};
+
+static char const insn_fpa_rounding[][2] = {
+	"", "p", "m", "z"
+};
+
+static char const insn_fpa_precision[][2] = {
+	"s", "d", "e", "p"
+};
+
+static char const insn_fpaconstants[][8] = {
+	"0.0", "1.0", "2.0", "3.0",
+	"4.0", "5.0", "0.5", "10.0"
+};
+
+#define insn_condition(x)	arm32_insn_conditions[(x >> 28) & 0x0f]
+#define insn_blktrans(x)	insn_block_transfers[(x >> 23) & 3]
+#define insn_stkblktrans(x)	insn_stack_block_transfers[(x >> 23) & 3]
+#define op2_shift(x)		op_shifts[(x >> 5) & 3]
+#define insn_fparnd(x)		insn_fpa_rounding[(x >> 5) & 0x03]
+#define insn_fpaprec(x)		insn_fpa_precision[(((x >> 18) & 2)|(x >> 7)) & 1]
+#define insn_fpaprect(x)	insn_fpa_precision[(((x >> 21) & 2)|(x >> 15)) & 1]
+#define insn_fpaimm(x)		insn_fpaconstants[x & 0x07]
+
+/* Local prototypes */
+static void disasm_register_shift(const disasm_interface_t *di, u_int insn);
+static void disasm_print_reglist(const disasm_interface_t *di, u_int insn);
+static void disasm_insn_ldrstr(const disasm_interface_t *di, u_int insn,
+    u_int loc);
+static void disasm_insn_ldrhstrh(const disasm_interface_t *di, u_int insn,
+    u_int loc);
+static void disasm_insn_ldcstc(const disasm_interface_t *di, u_int insn,
+    u_int loc);
+static u_int disassemble_readword(u_int address);
+static void disassemble_printaddr(u_int address);
+
+u_int
+disasm(const disasm_interface_t *di, u_int loc, int altfmt)
+{
+	const struct arm32_insn *i_ptr = &arm32_i[0];
+
+	u_int insn;
+	int matchp;
+	int branch;
+	const char* f_ptr;
+	int fmt;
+
+	fmt = 0;
+	matchp = 0;
+	insn = di->di_readword(loc);
+
+/*	di->di_printf("loc=%08x insn=%08x : ", loc, insn);*/
+
+	while (i_ptr->name) {
+		if ((insn & i_ptr->mask) ==  i_ptr->pattern) {
+			matchp = 1;
+			break;
+		}
+		i_ptr++;
+	}
+
+	if (!matchp) {
+		di->di_printf("und%s\t%08x\n", insn_condition(insn), insn);
+		return(loc + INSN_SIZE);
+	}
+
+	/* If instruction forces condition code, don't print it. */
+	if ((i_ptr->mask & 0xf0000000) == 0xf0000000)
+		di->di_printf("%s", i_ptr->name);
+	else
+		di->di_printf("%s%s", i_ptr->name, insn_condition(insn));
+
+	f_ptr = i_ptr->format;
+
+	/* Insert tab if there are no instruction modifiers */
+
+	if (*(f_ptr) < 'A' || *(f_ptr) > 'Z') {
+		++fmt;
+		di->di_printf("\t");
+	}
+
+	while (*f_ptr) {
+		switch (*f_ptr) {
+		/* 2 - print Operand 2 of a data processing instruction */
+		case '2':
+			if (insn & 0x02000000) {
+				int rotate= ((insn >> 7) & 0x1e);
+
+				di->di_printf("#0x%08x",
+					      (insn & 0xff) << (32 - rotate) |
+					      (insn & 0xff) >> rotate);
+			} else {  
+				disasm_register_shift(di, insn);
+			}
+			break;
+		/* d - destination register (bits 12-15) */
+		case 'd':
+			di->di_printf("r%d", ((insn >> 12) & 0x0f));
+			break;
+		/* D - insert 'p' if Rd is R15 */
+		case 'D':
+			if (((insn >> 12) & 0x0f) == 15)
+				di->di_printf("p");
+			break;
+		/* n - n register (bits 16-19) */
+		case 'n':
+			di->di_printf("r%d", ((insn >> 16) & 0x0f));
+			break;
+		/* s - s register (bits 8-11) */
+		case 's':
+			di->di_printf("r%d", ((insn >> 8) & 0x0f));
+			break;
+		/* o - indirect register rn (bits 16-19) (used by swap) */
+		case 'o':
+			di->di_printf("[r%d]", ((insn >> 16) & 0x0f));
+			break;
+		/* m - m register (bits 0-4) */
+		case 'm':
+			di->di_printf("r%d", ((insn >> 0) & 0x0f));
+			break;
+		/* a - address operand of ldr/str instruction */
+		case 'a':
+			disasm_insn_ldrstr(di, insn, loc);
+			break;
+		/* e - address operand of ldrh/strh instruction */
+		case 'e':
+			disasm_insn_ldrhstrh(di, insn, loc);
+			break;
+		/* l - register list for ldm/stm instruction */
+		case 'l':
+			disasm_print_reglist(di, insn);
+			break;
+		/* f - 1st fp operand (register) (bits 12-14) */
+		case 'f':
+			di->di_printf("f%d", (insn >> 12) & 7);
+			break;
+		/* g - 2nd fp operand (register) (bits 16-18) */
+		case 'g':
+			di->di_printf("f%d", (insn >> 16) & 7);
+			break;
+		/* h - 3rd fp operand (register/immediate) (bits 0-4) */
+		case 'h':
+			if (insn & (1 << 3))
+				di->di_printf("#%s", insn_fpaimm(insn));
+			else
+				di->di_printf("f%d", insn & 7);
+			break;
+		/* b - branch address */
+		case 'b':
+			branch = ((insn << 2) & 0x03ffffff);
+			if (branch & 0x02000000)
+				branch |= 0xfc000000;
+			di->di_printaddr(loc + 8 + branch);
+			break;
+		/* t - blx address */
+		case 't':
+			branch = ((insn << 2) & 0x03ffffff) |
+			    (insn >> 23 & 0x00000002);
+			if (branch & 0x02000000)
+				branch |= 0xfc000000;
+			di->di_printaddr(loc + 8 + branch);
+			break;
+		/* X - block transfer type */
+		case 'X':
+			di->di_printf("%s", insn_blktrans(insn));
+			break;
+		/* Y - block transfer type (r13 base) */
+		case 'Y':
+			di->di_printf("%s", insn_stkblktrans(insn));
+			break;
+		/* c - comment field bits(0-23) */
+		case 'c':
+			di->di_printf("0x%08x", (insn & 0x00ffffff));
+			break;
+		/* k - breakpoint comment (bits 0-3, 8-19) */
+		case 'k':
+			di->di_printf("0x%04x",
+			    (insn & 0x000fff00) >> 4 | (insn & 0x0000000f));
+			break;
+		/* p - saved or current status register */
+		case 'p':
+			if (insn & 0x00400000)
+				di->di_printf("spsr");
+			else
+				di->di_printf("cpsr");
+			break;
+		/* F - PSR transfer fields */
+		case 'F':
+			di->di_printf("_");
+			if (insn & (1 << 16))
+				di->di_printf("c");
+			if (insn & (1 << 17))
+				di->di_printf("x");
+			if (insn & (1 << 18))
+				di->di_printf("s");
+			if (insn & (1 << 19))
+				di->di_printf("f");
+			break;
+		/* B - byte transfer flag */
+		case 'B':
+			if (insn & 0x00400000)
+				di->di_printf("b");
+			break;
+		/* L - co-processor transfer size */
+		case 'L':
+			if (insn & (1 << 22))
+				di->di_printf("l");
+			break;
+		/* S - set status flag */
+		case 'S':
+			if (insn & 0x00100000)
+				di->di_printf("s");
+			break;
+		/* P - fp precision */
+		case 'P':
+			di->di_printf("%s", insn_fpaprec(insn));
+			break;
+		/* Q - fp precision (for ldf/stf) */
+		case 'Q':
+			break;
+		/* R - fp rounding */
+		case 'R':
+			di->di_printf("%s", insn_fparnd(insn));
+			break;
+		/* W - writeback flag */
+		case 'W':
+			if (insn & (1 << 21))
+				di->di_printf("!");
+			break;
+		/* # - co-processor number */
+		case '#':
+			di->di_printf("p%d", (insn >> 8) & 0x0f);
+			break;
+		/* v - co-processor data transfer registers+addressing mode */
+		case 'v':
+			disasm_insn_ldcstc(di, insn, loc);
+			break;
+		/* x - instruction in hex */
+		case 'x':
+			di->di_printf("0x%08x", insn);
+			break;
+		/* y - co-processor data processing registers */
+		case 'y':
+			di->di_printf("%d, ", (insn >> 20) & 0x0f);
+
+			di->di_printf("c%d, c%d, c%d", (insn >> 12) & 0x0f,
+			    (insn >> 16) & 0x0f, insn & 0x0f);
+
+			di->di_printf(", %d", (insn >> 5) & 0x07);
+			break;
+		/* z - co-processor register transfer registers */
+		case 'z':
+			di->di_printf("%d, ", (insn >> 21) & 0x07);
+			di->di_printf("r%d, c%d, c%d, %d",
+			    (insn >> 12) & 0x0f, (insn >> 16) & 0x0f,
+			    insn & 0x0f, (insn >> 5) & 0x07);
+
+/*			if (((insn >> 5) & 0x07) != 0)
+				di->di_printf(", %d", (insn >> 5) & 0x07);*/
+			break;
+		default:
+			di->di_printf("[%c - unknown]", *f_ptr);
+			break;
+		}
+		if (*(f_ptr+1) >= 'A' && *(f_ptr+1) <= 'Z')
+			++f_ptr;
+		else if (*(++f_ptr)) {
+			++fmt;
+			if (fmt == 1)
+				di->di_printf("\t");
+			else
+				di->di_printf(", ");
+		}
+	};
+
+	di->di_printf("\n");
+
+	return(loc + INSN_SIZE);
+}
+
+
+static void
+disasm_register_shift(const disasm_interface_t *di, u_int insn)
+{
+	di->di_printf("r%d", (insn & 0x0f));
+	if ((insn & 0x00000ff0) == 0)
+		;
+	else if ((insn & 0x00000ff0) == 0x00000060)
+		di->di_printf(", rrx");
+	else {
+		if (insn & 0x10)
+			di->di_printf(", %s r%d", op2_shift(insn),
+			    (insn >> 8) & 0x0f);
+		else
+			di->di_printf(", %s #%d", op2_shift(insn),
+			    (insn >> 7) & 0x1f);
+	}
+}
+
+
+static void
+disasm_print_reglist(const disasm_interface_t *di, u_int insn)
+{
+	int loop;
+	int start;
+	int comma;
+
+	di->di_printf("{");
+	start = -1;
+	comma = 0;
+
+	for (loop = 0; loop < 17; ++loop) {
+		if (start != -1) {
+			if (loop == 16 || !(insn & (1 << loop))) {
+				if (comma)
+					di->di_printf(", ");
+				else
+					comma = 1;
+        			if (start == loop - 1)
+        				di->di_printf("r%d", start);
+        			else
+        				di->di_printf("r%d-r%d", start, loop - 1);
+        			start = -1;
+        		}
+        	} else {
+        		if (insn & (1 << loop))
+        			start = loop;
+        	}
+        }
+	di->di_printf("}");
+
+	if (insn & (1 << 22))
+		di->di_printf("^");
+}
+
+static void
+disasm_insn_ldrstr(const disasm_interface_t *di, u_int insn, u_int loc)
+{
+	int offset;
+
+	offset = insn & 0xfff;
+	if ((insn & 0x032f0000) == 0x010f0000) {
+		/* rA = pc, immediate index */
+		if (insn & 0x00800000)
+			loc += offset;
+		else
+			loc -= offset;
+		di->di_printaddr(loc + 8);
+ 	} else {
+		di->di_printf("[r%d", (insn >> 16) & 0x0f);
+		if ((insn & 0x03000fff) != 0x01000000) {
+			di->di_printf("%s, ", (insn & (1 << 24)) ? "" : "]");
+			if (!(insn & 0x00800000))
+				di->di_printf("-");
+			if (insn & (1 << 25))
+				disasm_register_shift(di, insn);
+			else
+				di->di_printf("#0x%03x", offset);
+		}
+		if (insn & (1 << 24))
+			di->di_printf("]");
+	}
+}
+
+static void
+disasm_insn_ldrhstrh(const disasm_interface_t *di, u_int insn, u_int loc)
+{
+	int offset;
+
+	offset = ((insn & 0xf00) >> 4) | (insn & 0xf);
+	if ((insn & 0x004f0000) == 0x004f0000) {
+		/* rA = pc, immediate index */
+		if (insn & 0x00800000)
+			loc += offset;
+		else
+			loc -= offset;
+		di->di_printaddr(loc + 8);
+ 	} else {
+		di->di_printf("[r%d", (insn >> 16) & 0x0f);
+		if ((insn & 0x01400f0f) != 0x01400000) {
+			di->di_printf("%s, ", (insn & (1 << 24)) ? "" : "]");
+			if (!(insn & 0x00800000))
+				di->di_printf("-");
+			if (insn & (1 << 22))
+				di->di_printf("#0x%02x", offset);
+			else
+				di->di_printf("r%d", (insn & 0x0f));
+		}
+		if (insn & (1 << 24))
+			di->di_printf("]");
+	}
+}
+
+static void
+disasm_insn_ldcstc(const disasm_interface_t *di, u_int insn, u_int loc)
+{
+	if (((insn >> 8) & 0xf) == 1)
+		di->di_printf("f%d, ", (insn >> 12) & 0x07);
+	else
+		di->di_printf("c%d, ", (insn >> 12) & 0x0f);
+
+	di->di_printf("[r%d", (insn >> 16) & 0x0f);
+
+	di->di_printf("%s, ", (insn & (1 << 24)) ? "" : "]");
+
+	if (!(insn & (1 << 23)))
+		di->di_printf("-");
+
+	di->di_printf("#0x%03x", (insn & 0xff) << 2);
+
+	if (insn & (1 << 24))
+		di->di_printf("]");
+
+	if (insn & (1 << 21))
+		di->di_printf("!");
+}
+
+static u_int
+disassemble_readword(u_int address)
+{
+	return(*((u_int *)address));
+}
+
+static void
+disassemble_printaddr(u_int address)
+{
+	printf("0x%08x", address);
+}
+
+static void
+disassemble_printf(const char *fmt, ...) {
+	va_list ap;
+	va_start(ap, fmt);
+	vprintf(fmt, ap);
+	va_end(ap);
+}
+
+static const disasm_interface_t disassemble_di = {
+	disassemble_readword, disassemble_printaddr, disassemble_printf
+};
+
+void
+disassemble(u_int address)
+{
+
+	(void)disasm(&disassemble_di, address, 0);
+}
+
+/* End of disassem.c */
diff --git a/libacc/disassem.h b/libacc/disassem.h
new file mode 100644
index 0000000..02747cd
--- /dev/null
+++ b/libacc/disassem.h
@@ -0,0 +1,65 @@
+/*	$NetBSD: disassem.h,v 1.4 2001/03/04 04:15:58 matt Exp $	*/
+
+/*-
+ * Copyright (c) 1997 Mark Brinicombe.
+ * Copyright (c) 1997 Causality Limited.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by Mark Brinicombe.
+ * 4. The name of the company nor the name of the author may be used to
+ *    endorse or promote products derived from this software without specific
+ *    prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * Define the interface structure required by the disassembler.
+ *
+ * $FreeBSD: /repoman/r/ncvs/src/sys/arm/include/disassem.h,v 1.2 2005/01/05 21:58:48 imp Exp $
+ */
+
+#ifndef ANDROID_MACHINE_DISASSEM_H
+#define ANDROID_MACHINE_DISASSEM_H
+
+#include <sys/types.h>
+
+#if __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+	u_int	(*di_readword)(u_int);
+	void	(*di_printaddr)(u_int);	
+	void	(*di_printf)(const char *, ...);
+} disasm_interface_t;
+
+/* Prototypes for callable functions */
+
+u_int disasm(const disasm_interface_t *, u_int, int);
+void disassemble(u_int);
+
+#if __cplusplus
+}
+#endif
+
+#endif /* !ANDROID_MACHINE_DISASSEM_H */
diff --git a/libacc/test b/libacc/test
index 8bf33c8..0b767da 100755
--- a/libacc/test
+++ b/libacc/test
@@ -1,3 +1,3 @@
 #!/bin/sh
-g++ acc.cpp -g -ldl -o tests/acc && tests/acc tests/otcc.c -a x86 -d tests/otcc.out && diff tests/otcc.out tests/otcc.out-orig
-tests/acc tests/simplest.c
+g++ acc.cpp disassem.cpp -g -ldl -o tests/acc && tests/acc tests/otcc.c -a x86 -d tests/otcc.out && diff tests/otcc.out tests/otcc.out-orig
+tests/acc -S tests/returnval.c
diff --git a/libacc/tests/otcc.out-orig b/libacc/tests/otcc.out-orig
index 6b8bd59..fa14c72 100644
--- a/libacc/tests/otcc.out-orig
+++ b/libacc/tests/otcc.out-orig
Binary files differ
diff --git a/libacc/tests/returnval.c b/libacc/tests/returnval.c
new file mode 100644
index 0000000..3142fe2
--- /dev/null
+++ b/libacc/tests/returnval.c
@@ -0,0 +1,3 @@
+main() {
+  return 42;
+}
\ No newline at end of file