process.cc revision 11854 
1/*
2 * Copyright (c) 2004-2005 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: Gabe Black
29 *          Ali Saidi
30 *          Korey Sewell
31 */
32
33#include "arch/mips/process.hh"
34
35#include "arch/mips/isa_traits.hh"
36#include "base/loader/elf_object.hh"
37#include "base/loader/object_file.hh"
38#include "base/misc.hh"
39#include "cpu/thread_context.hh"
40#include "debug/Loader.hh"
41#include "mem/page_table.hh"
42#include "sim/aux_vector.hh"
43#include "sim/process.hh"
44#include "sim/process_impl.hh"
45#include "sim/syscall_return.hh"
46#include "sim/system.hh"
47
48using namespace std;
49using namespace MipsISA;
50
51MipsProcess::MipsProcess(ProcessParams * params, ObjectFile *objFile)
52    : Process(params, objFile)
53{
54    // Set up stack. On MIPS, stack starts at the top of kuseg
55    // user address space. MIPS stack grows down from here
56    stack_base = 0x7FFFFFFF;
57
58    // Set pointer for next thread stack.  Reserve 8M for main stack.
59    next_thread_stack_base = stack_base - (8 * 1024 * 1024);
60
61    // Set up break point (Top of Heap)
62    brk_point = objFile->dataBase() + objFile->dataSize() + objFile->bssSize();
63    brk_point = roundUp(brk_point, PageBytes);
64
65    // Set up region for mmaps.  Start it 1GB above the top of the heap.
66    mmap_end = brk_point + 0x40000000L;
67}
68
69void
70MipsProcess::initState()
71{
72    Process::initState();
73
74    argsInit<uint32_t>(PageBytes);
75}
76
77template<class IntType>
78void
79MipsProcess::argsInit(int pageSize)
80{
81    int intSize = sizeof(IntType);
82
83    // Patch the ld_bias for dynamic executables.
84    updateBias();
85
86    // load object file into target memory
87    objFile->loadSections(initVirtMem);
88
89    typedef AuxVector<IntType> auxv_t;
90    std::vector<auxv_t> auxv;
91
92    ElfObject * elfObject = dynamic_cast<ElfObject *>(objFile);
93    if (elfObject)
94    {
95        // Set the system page size
96        auxv.push_back(auxv_t(M5_AT_PAGESZ, MipsISA::PageBytes));
97        // Set the frequency at which time() increments
98        auxv.push_back(auxv_t(M5_AT_CLKTCK, 100));
99        // For statically linked executables, this is the virtual
100        // address of the program header tables if they appear in the
101        // executable image.
102        auxv.push_back(auxv_t(M5_AT_PHDR, elfObject->programHeaderTable()));
103        DPRINTF(Loader, "auxv at PHDR %08p\n", elfObject->programHeaderTable());
104        // This is the size of a program header entry from the elf file.
105        auxv.push_back(auxv_t(M5_AT_PHENT, elfObject->programHeaderSize()));
106        // This is the number of program headers from the original elf file.
107        auxv.push_back(auxv_t(M5_AT_PHNUM, elfObject->programHeaderCount()));
108        // This is the base address of the ELF interpreter; it should be
109        // zero for static executables or contain the base address for
110        // dynamic executables.
111        auxv.push_back(auxv_t(M5_AT_BASE, getBias()));
112        //The entry point to the program
113        auxv.push_back(auxv_t(M5_AT_ENTRY, objFile->entryPoint()));
114        //Different user and group IDs
115        auxv.push_back(auxv_t(M5_AT_UID, uid()));
116        auxv.push_back(auxv_t(M5_AT_EUID, euid()));
117        auxv.push_back(auxv_t(M5_AT_GID, gid()));
118        auxv.push_back(auxv_t(M5_AT_EGID, egid()));
119    }
120
121    // Calculate how much space we need for arg & env & auxv arrays.
122    int argv_array_size = intSize * (argv.size() + 1);
123    int envp_array_size = intSize * (envp.size() + 1);
124    int auxv_array_size = intSize * 2 * (auxv.size() + 1);
125
126    int arg_data_size = 0;
127    for (vector<string>::size_type i = 0; i < argv.size(); ++i) {
128        arg_data_size += argv[i].size() + 1;
129    }
130    int env_data_size = 0;
131    for (vector<string>::size_type i = 0; i < envp.size(); ++i) {
132        env_data_size += envp[i].size() + 1;
133    }
134
135    int space_needed =
136        argv_array_size +
137        envp_array_size +
138        auxv_array_size +
139        arg_data_size +
140        env_data_size;
141
142    // set bottom of stack
143    stack_min = stack_base - space_needed;
144    // align it
145    stack_min = roundDown(stack_min, pageSize);
146    stack_size = stack_base - stack_min;
147    // map memory
148    allocateMem(stack_min, roundUp(stack_size, pageSize));
149
150    // map out initial stack contents
151    IntType argv_array_base = stack_min + intSize; // room for argc
152    IntType envp_array_base = argv_array_base + argv_array_size;
153    IntType auxv_array_base = envp_array_base + envp_array_size;
154    IntType arg_data_base = auxv_array_base + auxv_array_size;
155    IntType env_data_base = arg_data_base + arg_data_size;
156
157    // write contents to stack
158    IntType argc = argv.size();
159
160    argc = htog((IntType)argc);
161
162    initVirtMem.writeBlob(stack_min, (uint8_t*)&argc, intSize);
163
164    copyStringArray(argv, argv_array_base, arg_data_base, initVirtMem);
165
166    copyStringArray(envp, envp_array_base, env_data_base, initVirtMem);
167
168    // Copy the aux vector
169    for (typename vector<auxv_t>::size_type x = 0; x < auxv.size(); x++) {
170        initVirtMem.writeBlob(auxv_array_base + x * 2 * intSize,
171                (uint8_t*)&(auxv[x].a_type), intSize);
172        initVirtMem.writeBlob(auxv_array_base + (x * 2 + 1) * intSize,
173                (uint8_t*)&(auxv[x].a_val), intSize);
174    }
175
176    // Write out the terminating zeroed auxilliary vector
177    for (unsigned i = 0; i < 2; i++) {
178        const IntType zero = 0;
179        const Addr addr = auxv_array_base + 2 * intSize * (auxv.size() + i);
180        initVirtMem.writeBlob(addr, (uint8_t*)&zero, intSize);
181    }
182
183    ThreadContext *tc = system->getThreadContext(contextIds[0]);
184
185    setSyscallArg(tc, 0, argc);
186    setSyscallArg(tc, 1, argv_array_base);
187    tc->setIntReg(StackPointerReg, stack_min);
188
189    tc->pcState(getStartPC());
190}
191
192
193MipsISA::IntReg
194MipsProcess::getSyscallArg(ThreadContext *tc, int &i)
195{
196    assert(i < 6);
197    return tc->readIntReg(FirstArgumentReg + i++);
198}
199
200void
201MipsProcess::setSyscallArg(ThreadContext *tc, int i, MipsISA::IntReg val)
202{
203    assert(i < 6);
204    tc->setIntReg(FirstArgumentReg + i, val);
205}
206
207void
208MipsProcess::setSyscallReturn(ThreadContext *tc, SyscallReturn sysret)
209{
210    if (sysret.successful()) {
211        // no error
212        tc->setIntReg(SyscallSuccessReg, 0);
213        tc->setIntReg(ReturnValueReg, sysret.returnValue());
214    } else {
215        // got an error, return details
216        tc->setIntReg(SyscallSuccessReg, (IntReg) -1);
217        tc->setIntReg(ReturnValueReg, sysret.errnoValue());
218    }
219}
220