src/arch/riscv/process.cc

   1 /*
   2  * Copyright (c) 2004-2005 The Regents of The University of Michigan
   3  * Copyright (c) 2016 The University of Virginia
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are
   8  * met: redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer;
  10  * redistributions in binary form must reproduce the above copyright
  11  * notice, this list of conditions and the following disclaimer in the
  12  * documentation and/or other materials provided with the distribution;
  13  * neither the name of the copyright holders nor the names of its
  14  * contributors may be used to endorse or promote products derived from
  15  * this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  18  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  20  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  21  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  22  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  23  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *
  29  * Authors: Gabe Black
  30  *          Ali Saidi
  31  *          Korey Sewell
  32  *          Alec Roelke
  33  */
  34 #include "arch/riscv/process.hh"
  35
  36 #include <vector>
  37
  38 #include "arch/riscv/isa_traits.hh"
  39 #include "base/loader/elf_object.hh"
  40 #include "base/loader/object_file.hh"
  41 #include "base/misc.hh"
  42 #include "cpu/thread_context.hh"
  43 #include "debug/Loader.hh"
  44 #include "mem/page_table.hh"
  45 #include "sim/process.hh"
  46 #include "sim/process_impl.hh"
  47 #include "sim/syscall_return.hh"
  48 #include "sim/system.hh"
  49
  50 using namespace std;
  51 using namespace RiscvISA;
  52
  53 RiscvProcess::RiscvProcess(ProcessParams * params,
  54     ObjectFile *objFile) : Process(params, objFile)
  55 {
  56     // Set up stack. On RISC-V, stack starts at the top of kuseg
  57     // user address space. RISC-V stack grows down from here
  58     stack_base = 0x7FFFFFFF;
  59
  60     // Set pointer for next thread stack.  Reserve 8M for main stack.
  61     next_thread_stack_base = stack_base - (8 * 1024 * 1024);
  62
  63     // Set up break point (Top of Heap)
  64     brk_point = objFile->bssBase() + objFile->bssSize();
  65
  66     // Set up region for mmaps.  Start it 1GB above the top of the heap.
  67     mmap_end = brk_point + 0x40000000L;
  68 }
  69
  70 void
  71 RiscvProcess::initState()
  72 {
  73     Process::initState();
  74
  75     argsInit<uint64_t>(PageBytes);
  76 }
  77
  78 template<class IntType> void
  79 RiscvProcess::argsInit(int pageSize)
  80 {
  81     updateBias();
  82
  83     // load object file into target memory
  84     objFile->loadSections(initVirtMem);
  85
  86     typedef AuxVector<IntType> auxv_t;
  87     vector<auxv_t> auxv;
  88     ElfObject * elfObject = dynamic_cast<ElfObject *>(objFile);
  89     if (elfObject) {
  90         // Set the system page size
  91         auxv.push_back(auxv_t(M5_AT_PAGESZ, RiscvISA::PageBytes));
  92         // Set the frequency at which time() increments
  93         auxv.push_back(auxv_t(M5_AT_CLKTCK, 100));
  94         // For statically linked executables, this is the virtual
  95         // address of the program header tables if they appear in the
  96         // executable image.
  97         auxv.push_back(auxv_t(M5_AT_PHDR, elfObject->programHeaderTable()));
  98         DPRINTF(Loader, "auxv at PHDR %08p\n",
  99             elfObject->programHeaderTable());
 100         // This is the size of a program header entry from the elf file.
 101         auxv.push_back(auxv_t(M5_AT_PHENT, elfObject->programHeaderSize()));
 102         // This is the number of program headers from the original elf file.
 103         auxv.push_back(auxv_t(M5_AT_PHNUM, elfObject->programHeaderCount()));
 104         auxv.push_back(auxv_t(M5_AT_BASE, getBias()));
 105         //The entry point to the program
 106         auxv.push_back(auxv_t(M5_AT_ENTRY, objFile->entryPoint()));
 107         //Different user and group IDs
 108         auxv.push_back(auxv_t(M5_AT_UID, uid()));
 109         auxv.push_back(auxv_t(M5_AT_EUID, euid()));
 110         auxv.push_back(auxv_t(M5_AT_GID, gid()));
 111         auxv.push_back(auxv_t(M5_AT_EGID, egid()));
 112     }
 113
 114     const IntType zero = 0;
 115     IntType argc = htog((IntType)argv.size());
 116     int argv_array_size = sizeof(Addr) * argv.size();
 117     int arg_data_size = 0;
 118     for (string arg: argv)
 119         arg_data_size += arg.size() + 1;
 120     int envp_array_size = sizeof(Addr) * envp.size();
 121     int env_data_size = 0;
 122     for (string env: envp)
 123         env_data_size += env.size() + 1;
 124     int auxv_array_size = 2 * sizeof(IntType)*auxv.size();
 125
 126     stack_size = sizeof(IntType) + argv_array_size + 2 * sizeof(Addr) +
 127         arg_data_size + 2 * sizeof(Addr);
 128     if (!envp.empty()) {
 129         stack_size += 2 * sizeof(Addr) + envp_array_size + 2 * sizeof(Addr) +
 130             env_data_size;
 131     }
 132     if (!auxv.empty())
 133         stack_size += 2 * sizeof(Addr) + auxv_array_size;
 134     stack_min = roundDown(stack_base - stack_size, pageSize);
 135     allocateMem(stack_min, roundUp(stack_size, pageSize));
 136
 137     Addr argv_array_base = stack_min + sizeof(IntType);
 138     Addr arg_data_base = argv_array_base + argv_array_size + 2 * sizeof(Addr);
 139     Addr envp_array_base = arg_data_base + arg_data_size;
 140     if (!envp.empty())
 141         envp_array_base += 2 * sizeof(Addr);
 142     Addr env_data_base = envp_array_base + envp_array_size;
 143     if (!envp.empty())
 144         env_data_base += 2 * sizeof(Addr);
 145
 146     vector<Addr> arg_pointers;
 147     if (!argv.empty()) {
 148         arg_pointers.push_back(arg_data_base);
 149         for (int i = 0; i < argv.size() - 1; i++) {
 150             arg_pointers.push_back(arg_pointers[i] + argv[i].size() + 1);
 151         }
 152     }
 153
 154     vector<Addr> env_pointers;
 155     if (!envp.empty()) {
 156         env_pointers.push_back(env_data_base);
 157         for (int i = 0; i < envp.size() - 1; i++) {
 158             env_pointers.push_back(env_pointers[i] + envp[i].size() + 1);
 159         }
 160     }
 161
 162     Addr sp = stack_min;
 163     initVirtMem.writeBlob(sp, (uint8_t *)&argc, sizeof(IntType));
 164     sp += sizeof(IntType);
 165     for (Addr arg_pointer: arg_pointers) {
 166         initVirtMem.writeBlob(sp, (uint8_t *)&arg_pointer, sizeof(Addr));
 167         sp += sizeof(Addr);
 168     }
 169     for (int i = 0; i < 2; i++) {
 170         initVirtMem.writeBlob(sp, (uint8_t *)&zero, sizeof(Addr));
 171         sp += sizeof(Addr);
 172     }
 173     for (int i = 0; i < argv.size(); i++) {
 174         initVirtMem.writeString(sp, argv[i].c_str());
 175         sp += argv[i].size() + 1;
 176     }
 177     if (!envp.empty()) {
 178         for (int i = 0; i < 2; i++) {
 179             initVirtMem.writeBlob(sp, (uint8_t *)&zero, sizeof(Addr));
 180             sp += sizeof(Addr);
 181         }
 182     }
 183     for (Addr env_pointer: env_pointers)
 184         initVirtMem.writeBlob(sp, (uint8_t *)&env_pointer, sizeof(Addr));
 185     if (!envp.empty()) {
 186         for (int i = 0; i < 2; i++) {
 187             initVirtMem.writeBlob(sp, (uint8_t *)&zero, sizeof(Addr));
 188             sp += sizeof(Addr);
 189         }
 190     }
 191     for (int i = 0; i < envp.size(); i++) {
 192         initVirtMem.writeString(sp, envp[i].c_str());
 193         sp += envp[i].size() + 1;
 194     }
 195     if (!auxv.empty()) {
 196         for (int i = 0; i < 2; i++) {
 197             initVirtMem.writeBlob(sp, (uint8_t *)&zero, sizeof(Addr));
 198             sp += sizeof(Addr);
 199         }
 200     }
 201     for (auxv_t aux: auxv) {
 202         initVirtMem.writeBlob(sp, (uint8_t *)&aux.a_type, sizeof(IntType));
 203         initVirtMem.writeBlob(sp + sizeof(IntType), (uint8_t *)&aux.a_val,
 204             sizeof(IntType));
 205         sp += 2 * sizeof(IntType);
 206     }
 207     for (int i = 0; i < 2; i++) {
 208         initVirtMem.writeBlob(sp, (uint8_t *)&zero, sizeof(Addr));
 209         sp += sizeof(Addr);
 210     }
 211
 212     ThreadContext *tc = system->getThreadContext(contextIds[0]);
 213     tc->setIntReg(StackPointerReg, stack_min);
 214     tc->pcState(getStartPC());
 215 }
 216
 217 RiscvISA::IntReg
 218 RiscvProcess::getSyscallArg(ThreadContext *tc, int &i)
 219 {
 220     // RISC-V only has four system call argument registers by convention, so
 221     // if a larger index is requested return 0
 222     RiscvISA::IntReg retval = 0;
 223     if (i < 4)
 224         retval = tc->readIntReg(SyscallArgumentRegs[i]);
 225     i++;
 226     return retval;
 227 }
 228
 229 void
 230 RiscvProcess::setSyscallArg(ThreadContext *tc, int i, RiscvISA::IntReg val)
 231 {
 232     tc->setIntReg(SyscallArgumentRegs[i], val);
 233 }
 234
 235 void
 236 RiscvProcess::setSyscallReturn(ThreadContext *tc, SyscallReturn sysret)
 237 {
 238     if (sysret.successful()) {
 239         // no error
 240         tc->setIntReg(SyscallPseudoReturnReg, sysret.returnValue());
 241     } else {
 242         // got an error, return details
 243         tc->setIntReg(SyscallPseudoReturnReg, sysret.errnoValue());
 244     }
 245 }