4a9dd1feb8
Libraries are loaded into the process address space using the mmap system call. Conveniently, this happens to be a good time to update the process symbol table with the library's incoming symbols so we handle the table update from within the system call. This works just like an application's normal symbols. The only difference between a dynamic library and a main executable is when the symbol table update occurs. The symbol table update for an executable happens at program load time and is finished before the process ever begins executing. Since dynamic linking happens at runtime, the symbol loading happens after the library is first loaded into the process address space. The library binary is examined at this time for a symbol section and that section is parsed for symbol types with specific bindings (global, local, weak). Subsequently, these symbols are added to the table and are available for use by gem5 for things like trace generation. Checkpointing should work just as it did previously. The address space (and therefore the library) will be recorded and the symbol table will be entirely recorded. (It's not possible to do anything clever like checkpoint a program and then load the program back with different libraries with LD_LIBRARY_PATH, because the library becomes part of the address space after being loaded.)
88 lines
3.6 KiB
C++
88 lines
3.6 KiB
C++
/*
|
|
* Copyright (c) 2013 The Regents of The University of Michigan
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are
|
|
* met: redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer;
|
|
* 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;
|
|
* neither the name of the copyright holders nor the names of its
|
|
* contributors may be used to endorse or promote products derived from
|
|
* this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "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 COPYRIGHT
|
|
* OWNER 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.
|
|
*
|
|
* Authors: Anthony Gutierrez
|
|
*/
|
|
|
|
#ifndef __DTB_OBJECT_HH__
|
|
#define __DTB_OBJECT_HH__
|
|
|
|
#include "base/loader/object_file.hh"
|
|
|
|
/** @file
|
|
* This implements an object file format to support loading
|
|
* and modifying flattened device tree blobs for use with
|
|
* current and future ARM Linux kernels.
|
|
*/
|
|
class DtbObject : public ObjectFile
|
|
{
|
|
protected:
|
|
DtbObject(const std::string &_filename, size_t _len, uint8_t *_data,
|
|
Arch _arch, OpSys _opSys);
|
|
|
|
/** Bool marking if this dtb file has replaced the original
|
|
* read in DTB file with a new modified buffer
|
|
*/
|
|
bool fileDataMmapped;
|
|
|
|
public:
|
|
virtual ~DtbObject();
|
|
|
|
/** Adds the passed in Command Line options for the kernel
|
|
* to the proper location in the device tree.
|
|
* @param _args command line to append
|
|
* @param len length of the command line string
|
|
* @return returns true on success, false otherwise
|
|
*/
|
|
bool addBootCmdLine(const char* _args, size_t len);
|
|
|
|
/** Parse the DTB file enough to find the provided release
|
|
* address and return it.
|
|
* @return release address for SMP boot
|
|
*/
|
|
Addr findReleaseAddr();
|
|
|
|
bool loadAllSymbols(SymbolTable *symtab, Addr base = 0,
|
|
Addr offset = 0, Addr addrMask = maxAddr);
|
|
bool loadGlobalSymbols(SymbolTable *symtab, Addr base = 0,
|
|
Addr offset = 0, Addr addrMask = maxAddr);
|
|
bool loadLocalSymbols(SymbolTable *symtab, Addr base = 0,
|
|
Addr offset = 0, Addr addrMask = maxAddr);
|
|
|
|
/** Static function that tries to load file as a
|
|
* flattened device tree blob.
|
|
* @param fname path to file
|
|
* @param len length of file
|
|
* @param data mmap'ed data buffer containing file contents
|
|
* @return ObjectFile representing closest match of file type
|
|
*/
|
|
static ObjectFile *tryFile(const std::string &fname,
|
|
size_t len, uint8_t *data);
|
|
};
|
|
|
|
#endif //__DTB_OBJECT_HH__
|