LXR qemu/disas/arm-a64.cc

   1/*
   2 * ARM A64 disassembly output wrapper to libvixl
   3 * Copyright (c) 2013 Linaro Limited
   4 * Written by Claudio Fontana
   5 *
   6 * This program is free software: you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation, either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20#include "qemu/osdep.h"
  21#include "disas/dis-asm.h"
  22
  23#include "vixl/a64/disasm-a64.h"
  24
  25using namespace vixl;
  26
  27static Decoder *vixl_decoder = NULL;
  28static Disassembler *vixl_disasm = NULL;
  29
  30/* We don't use libvixl's PrintDisassembler because its output
  31 * is a little unhelpful (trailing newlines, for example).
  32 * Instead we use our own very similar variant so we have
  33 * control over the format.
  34 */
  35class QEMUDisassembler : public Disassembler {
  36public:
  37    QEMUDisassembler() : printf_(NULL), stream_(NULL) { }
  38    ~QEMUDisassembler() { }
  39
  40    void SetStream(FILE *stream) {
  41        stream_ = stream;
  42    }
  43
  44    void SetPrintf(fprintf_function printf_fn) {
  45        printf_ = printf_fn;
  46    }
  47
  48protected:
  49    virtual void ProcessOutput(const Instruction *instr) {
  50        printf_(stream_, "%08" PRIx32 "      %s",
  51                instr->InstructionBits(), GetOutput());
  52    }
  53
  54private:
  55    fprintf_function printf_;
  56    FILE *stream_;
  57};
  58
  59static int vixl_is_initialized(void)
  60{
  61    return vixl_decoder != NULL;
  62}
  63
  64static void vixl_init() {
  65    vixl_decoder = new Decoder();
  66    vixl_disasm = new QEMUDisassembler();
  67    vixl_decoder->AppendVisitor(vixl_disasm);
  68}
  69
  70#define INSN_SIZE 4
  71
  72/* Disassemble ARM A64 instruction. This is our only entry
  73 * point from QEMU's C code.
  74 */
  75int print_insn_arm_a64(uint64_t addr, disassemble_info *info)
  76{
  77    uint8_t bytes[INSN_SIZE];
  78    uint32_t instrval;
  79    const Instruction *instr;
  80    int status;
  81
  82    status = info->read_memory_func(addr, bytes, INSN_SIZE, info);
  83    if (status != 0) {
  84        info->memory_error_func(status, addr, info);
  85        return -1;
  86    }
  87
  88    if (!vixl_is_initialized()) {
  89        vixl_init();
  90    }
  91
  92    ((QEMUDisassembler *)vixl_disasm)->SetPrintf(info->fprintf_func);
  93    ((QEMUDisassembler *)vixl_disasm)->SetStream(info->stream);
  94
  95    instrval = bytes[0] | bytes[1] << 8 | bytes[2] << 16 | bytes[3] << 24;
  96    instr = reinterpret_cast<const Instruction *>(&instrval);
  97    vixl_disasm->MapCodeAddress(addr, instr);
  98    vixl_decoder->Decode(instr);
  99
 100    return INSN_SIZE;
 101}
 102