dtb_object.cc revision 9538
1/* 2 * Copyright (c) 2013 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Anthony Gutierrez 29 */ 30 31#include <sys/mman.h> 32#include <err.h> 33#include <unistd.h> 34 35#include <cassert> 36 37#include "base/loader/dtb_object.hh" 38#include "fdt.h" 39#include "libfdt.h" 40 41ObjectFile * 42DtbObject::tryFile(const std::string &fname, int fd, size_t len, uint8_t *data) 43{ 44 // Check if this is a FDT file by looking for magic number 45 if (fdt_magic((void*)data) == FDT_MAGIC) { 46 return new DtbObject(fname, fd, len, data, 47 ObjectFile::UnknownArch, ObjectFile::UnknownOpSys); 48 } else { 49 return NULL; 50 } 51} 52 53DtbObject::DtbObject(const std::string &_filename, int _fd, 54 size_t _len, uint8_t *_data, 55 Arch _arch, OpSys _opSys) 56 : ObjectFile(_filename, _fd, _len, _data, _arch, _opSys) 57{ 58 text.baseAddr = 0; 59 text.size = len; 60 text.fileImage = fileData; 61 62 data.baseAddr = 0; 63 data.size = 0; 64 data.fileImage = NULL; 65 66 bss.baseAddr = 0; 67 bss.size = 0; 68 bss.fileImage = NULL; 69 70 fileDataMmapped = true; 71} 72 73DtbObject::~DtbObject() 74{ 75 if (descriptor >= 0) { 76 ::close(descriptor); 77 descriptor = -1; 78 } 79 80 // Make sure to clean up memory properly depending 81 // on how buffer was allocated. 82 if (fileData && !fileDataMmapped) { 83 delete [] fileData; 84 fileData = NULL; 85 } else if (fileData) { 86 munmap(fileData, len); 87 fileData = NULL; 88 } 89} 90 91bool 92DtbObject::addBootCmdLine(const char* _args, size_t len) 93{ 94 const char* root_path = "/"; 95 const char* node_name = "chosen"; 96 const char* full_path_node_name = "/chosen"; 97 const char* property_name = "bootargs"; 98 99 // Make a new buffer that has extra space to add nodes/properties 100 int newLen = 2*this->len; 101 uint8_t* fdt_buf_w_space = new uint8_t[newLen]; 102 // Copy and unpack flattened device tree into new buffer 103 int ret = fdt_open_into((void*)fileData, (void*)fdt_buf_w_space, (newLen)); 104 if (ret < 0) { 105 warn("Error resizing buffer of flattened device tree, " 106 "errno: %d\n", ret); 107 delete [] fdt_buf_w_space; 108 return false; 109 } 110 111 // First try finding the /chosen node in the dtb 112 int offset = fdt_path_offset((void*)fdt_buf_w_space, full_path_node_name); 113 if (offset < 0) { 114 // try adding the node by walking dtb tree to proper insertion point 115 offset = fdt_path_offset((void*)fdt_buf_w_space, root_path); 116 offset = fdt_add_subnode((void*)fdt_buf_w_space, offset, node_name); 117 offset = fdt_path_offset((void*)fdt_buf_w_space, full_path_node_name); 118 if (offset < 0) { 119 warn("Error finding or adding \"chosen\" subnode to flattened " 120 "device tree, errno: %d\n", offset); 121 delete [] fdt_buf_w_space; 122 return false; 123 } 124 } 125 126 // Set the bootargs property in the /chosen node 127 ret = fdt_setprop((void*)fdt_buf_w_space, offset, property_name, 128 (const void*)_args, len+1); 129 if (ret < 0) { 130 warn("Error setting \"bootargs\" property to flattened device tree, " 131 "errno: %d\n", ret); 132 delete [] fdt_buf_w_space; 133 return false; 134 } 135 136 // Repack the dtb for kernel use 137 ret = fdt_pack((void*)fdt_buf_w_space); 138 if (ret < 0) { 139 warn("Error re-packing flattened device tree structure, " 140 "errno: %d\n", ret); 141 delete [] fdt_buf_w_space; 142 return false; 143 } 144 145 text.size = newLen; 146 text.fileImage = fdt_buf_w_space; 147 148 // clean up old buffer and set to new fdt blob 149 munmap(fileData, this->len); 150 fileData = fdt_buf_w_space; 151 fileDataMmapped = false; 152 this->len = newLen; 153 154 return true; 155} 156 157bool 158DtbObject::loadGlobalSymbols(SymbolTable *symtab, Addr addrMask) 159{ 160 // nothing to do here 161 return false; 162} 163 164bool 165DtbObject::loadLocalSymbols(SymbolTable *symtab, Addr addrMask) 166{ 167 // nothing to do here 168 return false; 169} 170