src/base/loader/dtb_object.cc

   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 "base/loader/dtb_object.hh"
  32
  33 #include <sys/mman.h>
  34 #include <unistd.h>
  35
  36 #include <cassert>
  37
  38 #include "sim/byteswap.hh"
  39 #include "fdt.h"
  40 #include "libfdt.h"
  41
  42 ObjectFile *
  43 DtbObject::tryFile(const std::string &fname, size_t len, uint8_t *data)
  44 {
  45     // Check if this is a FDT file by looking for magic number
  46     if (fdt_magic((void*)data) == FDT_MAGIC) {
  47         return new DtbObject(fname, len, data,
  48                              ObjectFile::UnknownArch, ObjectFile::UnknownOpSys);
  49     } else {
  50         return NULL;
  51     }
  52 }
  53
  54 DtbObject::DtbObject(const std::string &_filename, size_t _len, uint8_t *_data,
  55                      Arch _arch, OpSys _opSys)
  56     : ObjectFile(_filename, _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
  73 DtbObject::~DtbObject()
  74 {
  75     // Make sure to clean up memory properly depending
  76     // on how buffer was allocated.
  77     if (fileData && !fileDataMmapped) {
  78         delete [] fileData;
  79         fileData = NULL;
  80     } else if (fileData) {
  81         munmap(fileData, len);
  82         fileData = NULL;
  83     }
  84 }
  85
  86 bool
  87 DtbObject::addBootCmdLine(const char* _args, size_t len)
  88 {
  89     const char* root_path = "/";
  90     const char* node_name = "chosen";
  91     const char* full_path_node_name = "/chosen";
  92     const char* property_name = "bootargs";
  93
  94     // Make a new buffer that has extra space to add nodes/properties
  95     int newLen = 2*this->len;
  96     uint8_t* fdt_buf_w_space = new uint8_t[newLen];
  97     // Copy and unpack flattened device tree into new buffer
  98     int ret = fdt_open_into((void*)fileData, (void*)fdt_buf_w_space, (newLen));
  99     if (ret < 0) {
 100         warn("Error resizing buffer of flattened device tree, "
 101              "errno: %d\n", ret);
 102         delete [] fdt_buf_w_space;
 103         return false;
 104     }
 105
 106     // First try finding the /chosen node in the dtb
 107     int offset = fdt_path_offset((void*)fdt_buf_w_space, full_path_node_name);
 108     if (offset < 0) {
 109         // try adding the node by walking dtb tree to proper insertion point
 110         offset = fdt_path_offset((void*)fdt_buf_w_space, root_path);
 111         offset = fdt_add_subnode((void*)fdt_buf_w_space, offset, node_name);
 112         // if we successfully add the subnode, get the offset
 113         if (offset >= 0)
 114           offset = fdt_path_offset((void*)fdt_buf_w_space, full_path_node_name);
 115
 116         if (offset < 0) {
 117             warn("Error finding or adding \"chosen\" subnode to flattened "
 118                  "device tree, errno: %d\n", offset);
 119             delete [] fdt_buf_w_space;
 120             return false;
 121         }
 122     }
 123
 124     // Set the bootargs property in the /chosen node
 125     ret = fdt_setprop((void*)fdt_buf_w_space, offset, property_name,
 126                       (const void*)_args, len+1);
 127     if (ret < 0) {
 128         warn("Error setting \"bootargs\" property to flattened device tree, "
 129              "errno: %d\n", ret);
 130         delete [] fdt_buf_w_space;
 131         return false;
 132     }
 133
 134     // Repack the dtb for kernel use
 135     ret = fdt_pack((void*)fdt_buf_w_space);
 136     if (ret < 0) {
 137         warn("Error re-packing flattened device tree structure, "
 138              "errno: %d\n", ret);
 139         delete [] fdt_buf_w_space;
 140         return false;
 141     }
 142
 143     text.size = newLen;
 144     text.fileImage = fdt_buf_w_space;
 145
 146     // clean up old buffer and set to new fdt blob
 147     munmap(fileData, this->len);
 148     fileData = fdt_buf_w_space;
 149     fileDataMmapped = false;
 150     this->len = newLen;
 151
 152     return true;
 153 }
 154
 155 Addr
 156 DtbObject::findReleaseAddr()
 157 {
 158     void *fd = (void*)fileData;
 159
 160     int offset = fdt_path_offset(fd, "/cpus/cpu@0");
 161     int len;
 162
 163     const void* temp = fdt_getprop(fd, offset, "cpu-release-addr", &len);
 164     Addr rel_addr = 0;
 165
 166     if (len > 3)
 167         rel_addr = betoh(*static_cast<const uint32_t*>(temp));
 168     if (len == 8)
 169         rel_addr = (rel_addr << 32) | betoh(*(static_cast<const uint32_t*>(temp)+1));
 170
 171     return rel_addr;
 172 }
 173
 174 bool
 175 DtbObject::loadAllSymbols(SymbolTable *symtab, Addr base, Addr offset,
 176                           Addr addr_mask)
 177 {
 178     return false;
 179 }
 180
 181 bool
 182 DtbObject::loadGlobalSymbols(SymbolTable *symtab, Addr base, Addr offset,
 183                              Addr addr_mask)
 184 {
 185     // nothing to do here
 186     return false;
 187 }
 188
 189 bool
 190 DtbObject::loadLocalSymbols(SymbolTable *symtab, Addr base, Addr offset,
 191                             Addr addr_mask)
 192 {
 193     // nothing to do here
 194     return false;
 195 }