dtb_object.cc revision 11793 
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 "fdt.h"
39#include "libfdt.h"
40#include "sim/byteswap.hh"
41
42ObjectFile *
43DtbObject::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
54DtbObject::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
73DtbObject::~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
86bool
87DtbObject::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
155Addr
156DtbObject::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
174bool
175DtbObject::loadAllSymbols(SymbolTable *symtab, Addr base, Addr offset,
176                          Addr addr_mask)
177{
178    return false;
179}
180
181bool
182DtbObject::loadGlobalSymbols(SymbolTable *symtab, Addr base, Addr offset,
183                             Addr addr_mask)
184{
185    // nothing to do here
186    return false;
187}
188
189bool
190DtbObject::loadLocalSymbols(SymbolTable *symtab, Addr base, Addr offset,
191                            Addr addr_mask)
192{
193    // nothing to do here
194    return false;
195}
196