add bxdisasm.cc - interactive instruction disassembler using bochs disasm engine (pre-alpha)

bochs/CHANGES

@@ -12,7 +12,7 @@ Changes after 2.6.9 release:
   ! CPUID Added Skylake-X CPU definition with AVX-512 support
 
 - Bochs Debugger and Instrumentation
-  - Added support for conditional stepping/continue and conditional breakpoints in Bochs debugger
+  - Added support for conditional breakpoints and conditional step/continue to Bochs debugger
   - Bochs debugger improvements patch by Doug Gale
     - better handling of 64-bit addresses in the debugger, added support for 64 bit symbols,
       added more symbol lookups.

bochs/bxdisasm.cc

@@ -0,0 +1,104 @@
+/////////////////////////////////////////////////////////////////////////
+// $Id$
+/////////////////////////////////////////////////////////////////////////
+//
+//   Copyright (c) 2014-2017 Stanislav Shwartsman
+//          Written by Stanislav Shwartsman [sshwarts at sourceforge net]
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2 of the License, or (at your option) any later version.
+//
+//  This library is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+/////////////////////////////////////////////////////////////////////////
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "config.h"
+#include "disasm/disasm.h"
+
+unsigned char char2byte(unsigned char input)
+{
+  if(input >= '0' && input <= '9')
+    return input - '0';
+  if(input >= 'A' && input <= 'F')
+    return input - 'A' + 10;
+  if(input >= 'a' && input <= 'f')
+    return input - 'a' + 10;
+
+  return 0; // wrong input, ignore
+}
+
+// This function assumes src to be a zero terminated sanitized string with
+// an even number of [0-9a-f] characters, and target to be sufficiently large
+void hex2bin(Bit8u* target, const char* src, unsigned len)
+{
+  while(len >= 2 && src[0] && src[1])
+  {
+    *(target++) = (unsigned) char2byte(src[0])*16 + (unsigned) char2byte(src[1]);
+    src += 2;
+    len -= 2;
+  }
+}
+
+int main(int argn, const char **argv)
+{
+  disassembler bx_disassemble;
+  char disbuf[256];
+  Bit8u ibuf[16] = {0};
+  bx_bool is_32 = 1, is_64 = 0;
+  unsigned len;
+
+  if (argn < 2)
+  {
+    printf("Usage: bxdisasm [-16|-32|-64] string-of-instruction-bytes\n");
+    exit(1);
+  }
+
+  for (unsigned i=1;i<argn;i++) {
+    if (!strcmp(argv[i], "-16")) {
+      is_32 = 0;
+      is_64 - 0;
+      continue;
+    }
+    if (!strcmp(argv[i], "-32")) {
+      is_32 = 1;
+      is_64 - 0;
+      continue;
+    }
+    if (!strcmp(argv[i], "-64")) {
+      is_32 = 1;
+      is_64 - 1;
+      continue;
+    }
+
+    const char *p = argv[i];
+    unsigned len = strlen(p);
+    if (len > 32) len = 32;
+    hex2bin(ibuf, p, len);
+  }
+
+  printf("instruction bytes:");
+  for (int i=0;i<16;i++)
+    printf("%02x ", ibuf[i]);
+  printf("\n");
+
+  bx_disassemble.set_syntax_intel();
+  unsigned ilen = bx_disassemble.disasm(is_32, is_64, 0U, 0U, ibuf, disbuf);
+  printf("disasm: %s\n", disbuf);
+
+  bx_disassemble.set_syntax_att();
+  ilen = bx_disassemble.disasm(is_32, is_64, 0U, 0U, ibuf, disbuf);
+  printf("disasm: %s\n", disbuf);
+}