调试Bochs在Linux Mint下面symbol not found的问题

在我的Linux Mint上使用Bochs时出现了很奇怪的问题，按照http://www.cnblogs.com/long123king/p/3568575.html步骤

会提示：

symbol not found

 因此，我决定使用gdb调试Bochs找出究竟发生了什么奇怪的问题。

1. 如何配置.conf.linux

添加-g -O0到CFLAGS/CXXFLAGS

2. 重新生成bochs程序

sudo make bochs

 3. 参考：http://code.google.com/p/stl-debug/

添加对STL容器的调试支持

调试:

sudo gdb --args ~/latest_bochs/bochs/bochs -q -f bxrc_custom -rc script_debug_custom

 4. 添加如下代码：

symbol_entry_t* context_t::get_symbol_entry(const char *symbol) const
{
  if (m_rsyms.empty())
    return 0;

  symbol_entry_t probe(0, symbol);
  rsym_set_t::const_iterator iter;
  for (std::set<symbol_entry_t*, lt_rsymbol_entry_t>::iterator it = m_rsyms.begin();
        it != m_rsyms.end();
        it++)
  {
        unsigned long start = (*it)->start;
        char* name = (*it)->name;
        if (strncmp(name, "start_kernel", strlen("start_kernel")) == 0)
        {
                int kkk = 0;
        }
        dbg_printf("0x%08X : %s
", start, name);
        continue;
  }
  iter=m_rsyms.find(&probe);
  if(iter==m_rsyms.end()) // No symbol found
    return 0;
  return *iter;
}
    ++sym_name;

    char *ending = (sym_name + strlen(sym_name) - 1);
    while ( isspace(*ending) && ending != sym_name)
{
        *(ending--) = '';
}

    symbol_entry_t* sym = new symbol_entry_t(addr + offset, sym_name);

 在int kkk=0;这一行设置断点，发现：

Breakpoint 1, context_t::get_symbol_entry (this=0x2860cf0, symbol=0x2860cd0 "start_kernel") at symbols.cc:213
213			int kkk = 0;
(gdb) info locals
kkk = 0
start = 3246113809
name = 0x3155e30 "start_kernel
"
it = {_M_node = 0x3155e80}
probe = {name = 0x2536e70 "start_kernel", start = 0}
iter = {_M_node = 0x0}

 怎么会多了一个" "呢，相信这就是问题的所在。

在add_symbol处设置断点，重新调试

Breakpoint 2, context_t::add_symbol (this=0x2860cf0, sym=0x2860fa0) at symbols.cc:226
226	  m_syms.insert(sym);
(gdb) print sym.start
$1 = 0
(gdb) print sym.name
$2 = 0x2860fc0 "VDSO32_PRELINK
"
(gdb) 

 确认问题。

解决方法：

在bx_dbg_symbol_command函数中添加如下代码：

    ++sym_name;

    char *ending = (sym_name + strlen(sym_name) - 1);
    while ( isspace(*ending) && ending != sym_name)
{
        *(ending--) = '';
}

    symbol_entry_t* sym = new symbol_entry_t(addr + offset, sym_name);