boot1.c

linux下用PCMCIA无线网卡虚拟无线AP的程序源码

							_dl_dprintf(2, "%s: can't load library '%s'\n", 
								_dl_progname, lpnt);
							_dl_exit(16);
#ifdef DL_TRACE
						}
#endif
					} else {
#ifdef DL_TRACE
						if (_dl_trace_loaded_objects && !tpnt1->usage_count)
							_dl_dprintf(1, "\t%s => %s (0x%x)\n", lpnt, tpnt1->libname, 
								(unsigned) tpnt1->loadaddr);
#endif
						rpnt->next = (struct dyn_elf *)
							_dl_malloc(sizeof(struct dyn_elf));
						_dl_memset(rpnt->next, 0, sizeof(*(rpnt->next)));
						rpnt = rpnt->next;
						tpnt1->usage_count++;
						tpnt1->symbol_scope = _dl_symbol_tables;
						tpnt1->libtype = elf_lib;
						rpnt->dyn = tpnt1;
					}
				}
			}
		}
	}

#ifdef USE_CACHE
	_dl_unmap_cache();
#endif
	/* ldd uses uses this.  I am not sure how you pick up the other flags */
#ifdef DL_TRACE
	if (_dl_trace_loaded_objects) {
		char *_dl_warn = 0;
		_dl_warn = _dl_getenv("LD_WARN", envp);
		if (!_dl_warn)
			_dl_exit(0);
	}
#endif

	/*
	 * If the program interpreter is not in the module chain, add it.  This will
	 * be required for dlopen to be able to access the internal functions in the 
	 * dynamic linker.
	 */
	if (tpnt) {
		struct elf_resolve *tcurr;

		tcurr = _dl_loaded_modules;
		if (tcurr)
			while (tcurr->next)
				tcurr = tcurr->next;
		tpnt->next = NULL;
		tpnt->usage_count++;

		if (tcurr) {
			tcurr->next = tpnt;
			tpnt->prev = tcurr;
		} else {
			_dl_loaded_modules = tpnt;
			tpnt->prev = NULL;
		}
		if (rpnt) {
			rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
			_dl_memset(rpnt->next, 0, sizeof(*(rpnt->next)));
			rpnt = rpnt->next;
		} else {
			rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
			_dl_memset(rpnt, 0, sizeof(*(rpnt->next)));
		}
		rpnt->dyn = tpnt;
		tpnt = NULL;
	}

	/*
	 * OK, now all of the kids are tucked into bed in their proper addresses.
	 * Now we go through and look for REL and RELA records that indicate fixups
	 * to the GOT tables.  We need to do this in reverse order so that COPY
	 * directives work correctly */
	goof = _dl_loaded_modules ? _dl_fixup(_dl_loaded_modules) : 0;


	/* Some flavors of SVr4 do not generate the R_*_COPY directive,
	   and we have to manually search for entries that require fixups. 
	   Solaris gets this one right, from what I understand.  */

	if (_dl_symbol_tables)
		goof += _dl_copy_fixups(_dl_symbol_tables);
#ifdef DL_TRACE
	if (goof || _dl_trace_loaded_objects)
		_dl_exit(0);
#endif

	/* OK, at this point things are pretty much ready to run.  Now we
	   need to touch up a few items that are required, and then
	   we can let the user application have at it.  Note that
	   the dynamic linker itself is not guaranteed to be fully
	   dynamicly linked if we are using ld.so.1, so we have to look
	   up each symbol individually. */


	_dl_brkp = (unsigned long *) _dl_find_hash("___brk_addr", NULL, 1, NULL, 0);
	if (_dl_brkp)
		*_dl_brkp = brk_addr;
	_dl_envp =
		(unsigned long *) _dl_find_hash("__environ", NULL, 1, NULL, 0);

	if (_dl_envp)
		*_dl_envp = (unsigned long) envp;
	{
		int i;
		elf_phdr *ppnt;

		/* We had to set the protections of all pages to R/W for dynamic linking.
		   Set text pages back to R/O */
		for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next)
			for (ppnt = tpnt->ppnt, i = 0; i < tpnt->n_phent; i++, ppnt++)
				if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W) &&
					tpnt->dynamic_info[DT_TEXTREL])
					_dl_mprotect((void *) (tpnt->loadaddr + (ppnt->p_vaddr & 0xfffff000)), 
						(ppnt->p_vaddr & 0xfff) + (unsigned long) ppnt->p_filesz, 
						LXFLAGS(ppnt->p_flags));

	}

	_dl_atexit = (int (*)(void *)) _dl_find_hash("atexit", NULL, 1, NULL, 0);

	/*
	 * OK, fix one more thing - set up the debug_addr structure to point
	 * to our chain.  Later we may need to fill in more fields, but this
	 * should be enough for now.
	 */
	debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
	debug_addr->r_version = 1;
	debug_addr->r_ldbase = load_addr;
	debug_addr->r_brk = (unsigned long) &_dl_debug_state;
	_dl_debug_addr = debug_addr;
	debug_addr->r_state = RT_CONSISTENT;
	/* This is written in this funny way to keep gcc from inlining the
	   function call. */
	((void (*)(void)) debug_addr->r_brk) ();

	for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
		/* Apparently crt1 for the application is responsible for handling this.
		 * We only need to run the init/fini for shared libraries
		 */
		if (tpnt->libtype == program_interpreter ||
			tpnt->libtype == elf_executable)
			continue;
		if (tpnt->init_flag & INIT_FUNCS_CALLED)
			continue;
		tpnt->init_flag |= INIT_FUNCS_CALLED;

		if (tpnt->dynamic_info[DT_INIT]) {
			_dl_elf_init = (int (*)(void)) (tpnt->loadaddr + 
				tpnt->dynamic_info[DT_INIT]);
			(*_dl_elf_init) ();
		}
		if (_dl_atexit && tpnt->dynamic_info[DT_FINI]) {
			(*_dl_atexit) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
		}
#undef DL_DEBUG
#ifdef DL_DEBUG
		else {
			_dl_dprintf(2, tpnt->libname);
			_dl_dprintf(2, ": ");
			if (!_dl_atexit)
				_dl_dprintf(2, "The address is atexit () is 0x0.");
			if (!tpnt->dynamic_info[DT_FINI])
				_dl_dprintf(2, "Invalid .fini section.");
			_dl_dprintf(2, "\n");
		}
#endif
#undef DL_DEBUG
	}

	/* OK we are done here.  Turn out the lights, and lock up. */
	_dl_elf_main = (int (*)(int, char **, char **)) auxv_t[AT_ENTRY].a_un.a_fcn;


	/*
	 * Transfer control to the application.
	 */
	status = 0; /* Used on x86, but not on other arches */
	START();
}

/*
 * This stub function is used by some debuggers.  The idea is that they
 * can set an internal breakpoint on it, so that we are notified when the
 * address mapping is changed in some way.
 */
void _dl_debug_state()
{
	return;
}

int _dl_fixup(struct elf_resolve *tpnt)
{
	int goof = 0;
	
	if (tpnt->next)
		goof += _dl_fixup(tpnt->next);
	if (tpnt->dynamic_info[DT_REL]) {
#ifdef ELF_USES_RELOCA
		_dl_dprintf(2, "%s: can't handle REL relocation records\n", 
			_dl_progname);
		_dl_exit(17);
#else
		if (tpnt->init_flag & RELOCS_DONE)
			return goof;
		tpnt->init_flag |= RELOCS_DONE;
		goof += _dl_parse_relocation_information(tpnt, 
			tpnt->dynamic_info[DT_REL], tpnt->dynamic_info[DT_RELSZ], 0);
#endif
	}
	if (tpnt->dynamic_info[DT_RELA]) {
#ifdef ELF_USES_RELOCA
		if (tpnt->init_flag & RELOCS_DONE)
			return goof;
		tpnt->init_flag |= RELOCS_DONE;
		goof += _dl_parse_relocation_information(tpnt, 
			tpnt->dynamic_info[DT_RELA], tpnt->dynamic_info[DT_RELASZ], 0);
#else
		_dl_dprintf(2, "%s: can't handle RELA relocation records\n", 
			_dl_progname);
		_dl_exit(18);
#endif
	}
	if (tpnt->dynamic_info[DT_JMPREL]) {
		if (tpnt->init_flag & JMP_RELOCS_DONE)
			return goof;
		tpnt->init_flag |= JMP_RELOCS_DONE;
		if (!_dl_not_lazy || *_dl_not_lazy == 0)
			_dl_parse_lazy_relocation_information(tpnt, 
				tpnt->dynamic_info[DT_JMPREL], tpnt->dynamic_info[DT_PLTRELSZ], 0);
		else
			goof += _dl_parse_relocation_information(tpnt, 
				tpnt->dynamic_info[DT_JMPREL], tpnt->dynamic_info[DT_PLTRELSZ], 0);
	}
	return goof;
}

void *_dl_malloc(int size)
{
	void *retval;

#ifdef DL_DEBUG
	SEND_STDERR("malloc: request for ");
	SEND_NUMBER_STDERR(size, 0);
	SEND_STDERR(" bytes\n");
#endif	

	if (_dl_malloc_function)
		return (*_dl_malloc_function) (size);

	if (_dl_malloc_addr - _dl_mmap_zero + size > 4096) {
#ifdef DL_DEBUG
		SEND_STDERR("malloc: mmapping more memory\n");
#endif	
		_dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size, 
			PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
		if (_dl_mmap_check_error(_dl_mmap_zero)) {
			_dl_dprintf(2, "%s: mmap of a spare page failed!\n", _dl_progname);
			_dl_exit(20);
		}
	}
	retval = _dl_malloc_addr;
	_dl_malloc_addr += size;

	/*
	 * Align memory to 4 byte boundary.  Some platforms require this, others
	 * simply get better performance.
	 */
	_dl_malloc_addr = (char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3));
	return retval;
}

char *_dl_getenv(char *symbol, char **envp)
{
	char *pnt;
	char *pnt1;

	while ((pnt = *envp++)) {
		pnt1 = symbol;
		while (*pnt && *pnt == *pnt1)
			pnt1++, pnt++;
		if (!*pnt || *pnt != '=' || *pnt1)
			continue;
		return pnt + 1;
	}
	return 0;
}

void _dl_unsetenv(char *symbol, char **envp)
{
	char *pnt;
	char *pnt1;
	char **newenvp = envp;

	for (pnt = *envp; pnt; pnt = *++envp) {
		pnt1 = symbol;
		while (*pnt && *pnt == *pnt1)
			pnt1++, pnt++;
		if (!*pnt || *pnt != '=' || *pnt1)
			*newenvp++ = *envp;
	}
	*newenvp++ = *envp;
	return;
}

char *_dl_strdup(const char *string)
{
	char *retval;
	int len;

	len = _dl_strlen(string);
	retval = _dl_malloc(len + 1);
	_dl_strcpy(retval, string);
	return retval;
}

/* Minimum printf which handles only characters, %d's and %s's */
void _dl_dprintf(int fd, const char *fmt, ...)
{
    int num;
    va_list args;
    char *start, *ptr, *string;
    char buf[2048];

    start = ptr = buf;
    
    if (!fmt)
	return;

    if (_dl_strlen(fmt) >= (sizeof(buf)-1))
	_dl_write(fd, "(overflow)\n", 10);

    _dl_strcpy(buf, fmt);
    va_start(args, fmt);

    while(start)
    {
	while(*ptr != '%' && *ptr) { 
	    ptr++;
	}

	if(*ptr == '%')
	{
	    *ptr++ = '\0';
	    _dl_write(fd, start, _dl_strlen(start));

	    switch(*ptr++)
	    {
		case 's':
		    string = va_arg(args, char *);
		    if (!string)
			_dl_write(fd, "(null)", 6);
		    else
			_dl_write(fd, string, _dl_strlen(string));
		    break;

		case 'i':
		case 'd':
		    {
			char tmp[13];
			num = va_arg(args, int);
			string = _dl_simple_ltoa(tmp, num);
			_dl_write(fd, string, _dl_strlen(string));
			break;
		    }
		case 'x':
		case 'X':
		    {
			char tmp[13];
			num = va_arg(args, int);
			string = _dl_simple_ltoahex(tmp, num);
			_dl_write(fd, string, _dl_strlen(string));
			break;
		    }
		default:
			_dl_write(fd, "(null)", 6);
			break;
	    }

	    start = ptr;
	}
	else
	{
	    _dl_write(fd, start, _dl_strlen(start));
	    start = NULL;
	}
    }
    return;
}