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loader: add a flattened device tree blob (dtb) object

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this adds a dtb_object so the loader can load in the dtb
file for linux/android ARM kernels.
This commit is contained in:
Anthony Gutierrez 2013-02-15 18:48:59 -05:00
parent ba983f9387
commit f7107fb795
5 changed files with 270 additions and 0 deletions
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15
src/arch/arm/linux/system.cc
View file

@ -45,6 +45,7 @@
#include "arch/arm/isa_traits.hh"
#include "arch/arm/utility.hh"
#include "arch/generic/linux/threadinfo.hh"
#include "base/loader/dtb_object.hh"
#include "base/loader/object_file.hh"
#include "base/loader/symtab.hh"
#include "cpu/base.hh"
@ -143,6 +144,20 @@ LinuxArmSystem::initState()
if (!dtb_file) {
fatal("couldn't load DTB file: %s\n", params()->dtb_filename);
}
DtbObject *_dtb_file = dynamic_cast<DtbObject*>(dtb_file);
if (_dtb_file) {
if (!_dtb_file->addBootCmdLine(params()->boot_osflags.c_str(),
params()->boot_osflags.size())) {
warn("couldn't append bootargs to DTB file: %s\n",
params()->dtb_filename);
}
} else {
warn("dtb_file cast failed; couldn't append bootargs "
"to DTB file: %s\n", params()->dtb_filename);
}
dtb_file->setTextBase(params()->atags_addr);
dtb_file->loadSections(physProxy);
delete dtb_file;

1
src/base/SConscript
View file

@ -63,6 +63,7 @@ Source('types.cc')
Source('userinfo.cc')
Source('loader/aout_object.cc')
Source('loader/dtb_object.cc')
Source('loader/ecoff_object.cc')
Source('loader/elf_object.cc')
Source('loader/hex_file.cc')

169
src/base/loader/dtb_object.cc Normal file
View file

@ -0,0 +1,169 @@
/*
* 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
*/
#include <sys/mman.h>
#include <err.h>
#include <unistd.h>
#include <cassert>
#include "base/loader/dtb_object.hh"
#include "fdt.h"
#include "libfdt.h"
ObjectFile *
DtbObject::tryFile(const std::string &fname, int fd, size_t len, uint8_t *data)
{
// Check if this is a FDT file by looking for magic number
if (fdt_magic((void*)data) == FDT_MAGIC) {
return new DtbObject(fname, fd, len, data,
ObjectFile::UnknownArch, ObjectFile::UnknownOpSys);
} else {
return NULL;
}
}
DtbObject::DtbObject(const std::string &_filename, int _fd,
size_t _len, uint8_t *_data,
Arch _arch, OpSys _opSys)
: ObjectFile(_filename, _fd, _len, _data, _arch, _opSys)
{
text.baseAddr = 0;
text.size = len;
text.fileImage = fileData;
data.baseAddr = 0;
data.size = 0;
data.fileImage = NULL;
bss.baseAddr = 0;
bss.size = 0;
bss.fileImage = NULL;
fileDataMmapped = true;
}
DtbObject::~DtbObject()
{
if (descriptor >= 0) {
::close(descriptor);
descriptor = -1;
}
// Make sure to clean up memory properly depending
// on how buffer was allocated.
if (fileData && !fileDataMmapped) {
delete [] fileData;
fileData = NULL;
} else if (fileData) {
munmap(fileData, len);
fileData = NULL;
}
}
bool
DtbObject::addBootCmdLine(const char* _args, size_t len)
{
const char* root_path = "/";
const char* node_name = "chosen";
const char* full_path_node_name = "/chosen";
const char* property_name = "bootargs";
// Make a new buffer that has extra space to add nodes/properties
int newLen = 2*this->len;
uint8_t* fdt_buf_w_space = new uint8_t[newLen];
// Copy and unpack flattened device tree into new buffer
int ret = fdt_open_into((void*)fileData, (void*)fdt_buf_w_space, (newLen));
if (ret < 0) {
warn("Error resizing buffer of flattened device tree, "
"errno: %d\n", ret);
delete [] fdt_buf_w_space;
return false;
}
// First try finding the /chosen node in the dtb
int offset = fdt_path_offset((void*)fdt_buf_w_space, full_path_node_name);
if (offset < 0) {
// try adding the node by walking dtb tree to proper insertion point
offset = fdt_path_offset((void*)fdt_buf_w_space, root_path);
offset = fdt_add_subnode((void*)fdt_buf_w_space, offset, node_name);
offset = fdt_path_offset((void*)fdt_buf_w_space, full_path_node_name);
if (offset < 0) {
warn("Error finding or adding \"chosen\" subnode to flattened "
"device tree, errno: %d\n", offset);
delete [] fdt_buf_w_space;
return false;
}
}
// Set the bootargs property in the /chosen node
ret = fdt_setprop((void*)fdt_buf_w_space, offset, property_name,
(const void*)_args, len+1);
if (ret < 0) {
warn("Error setting \"bootargs\" property to flattened device tree, "
"errno: %d\n", ret);
delete [] fdt_buf_w_space;
return false;
}
// Repack the dtb for kernel use
ret = fdt_pack((void*)fdt_buf_w_space);
if (ret < 0) {
warn("Error re-packing flattened device tree structure, "
"errno: %d\n", ret);
delete [] fdt_buf_w_space;
return false;
}
text.size = newLen;
text.fileImage = fdt_buf_w_space;
// clean up old buffer and set to new fdt blob
munmap(fileData, this->len);
fileData = fdt_buf_w_space;
fileDataMmapped = false;
this->len = newLen;
return true;
}
bool
DtbObject::loadGlobalSymbols(SymbolTable *symtab, Addr addrMask)
{
// nothing to do here
return false;
}
bool
DtbObject::loadLocalSymbols(SymbolTable *symtab, Addr addrMask)
{
// nothing to do here
return false;
}

80
src/base/loader/dtb_object.hh Normal file
View file

@ -0,0 +1,80 @@
/*
* 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, int _fd,
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);
bool loadGlobalSymbols(SymbolTable *symtab,
Addr addrMask = std::numeric_limits<Addr>::max());
bool loadLocalSymbols(SymbolTable *symtab,
Addr addrMask = std::numeric_limits<Addr>::max());
/** Static function that tries to load file as a
* flattened device tree blob.
* @param fname path to file
* @param fd file descriptor of object 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, int fd,
size_t len, uint8_t *data);
};
#endif //__DTB_OBJECT_HH__

5
src/base/loader/object_file.cc
View file

@ -39,6 +39,7 @@
#include <string>
#include "base/loader/aout_object.hh"
#include "base/loader/dtb_object.hh"
#include "base/loader/ecoff_object.hh"
#include "base/loader/elf_object.hh"
#include "base/loader/object_file.hh"
@ -140,6 +141,10 @@ createObjectFile(const string &fname, bool raw)
return fileObj;
}
if ((fileObj = DtbObject::tryFile(fname, fd, len, fileData)) != NULL) {
return fileObj;
}
if (raw)
return RawObject::tryFile(fname, fd, len, fileData);