COREMU 著墨在 system mode，不支援 process mode。COREMU 需要 root 權限設定執行緒的優先權。如果要以一般使用者執行 COREMU，請自己把會噴 assert 的地方關掉。 請閱讀 coremu/README。

1. 安裝 libtopology。請見 Portable Hardware Locality。

   $ wget http://sourceforge.net/projects/coremu/files/coremu-img/libtopology-0.9.tar.gz/download
   $ tar xvf libtopology-0.9.tar.gz
   $ mkdir build; cd build
   $ ../libtopology-0.9/configure --prefix=$INSTALL
   $ make; make install

2. 安裝 COREMU。

   $ wget http://sourceforge.net/projects/coremu/files/coremu-0.1.2.tar.gz/download
   # coremu-0.1.2 目錄底下分別有兩個目錄:
   # coremu: COREMU 核心函式庫
   # qemu: QEMU 0.13 補丁版
   $ tar xvf coremu-0.1.2.tar.gz
   $ cd coremu
   # 修改 configure。
   # --extra-cflags="-I${coremuroot}/incl -g -I/tmp/chenwj/install" \
   # --extra-ldflags="-L/tmp/chenwj/install/lib" \
   # 將 PKG_CONFIG_PATH 指向編譯 libtopology 所在的目錄 
   $ export PKG_CONFIG_PATH=$BUILD/topology.pc
   $ ./configure --target=arm --prefix=$INSTALL ../qemu
   $ make; make install

3. 下載映像檔。

   $ wget http://sourceforge.net/projects/coremu/files/coremu-img/debian-x86_64.img.gz/download
   $ cd coremu/scripts
   $ export LD_LIBRARY_PATH=/PATH/TO/libtopology.so
   $ ./x86_64-linux.sh <path2qemu> <path2img> <core number>
   $ ./arm-linux.sh ~/install/atomic/bin/qemu-system-arm arm-zImage-2.6.28 arm-initrd.gz 1

1. 進入主要執行迴圈之前，COREMU 會做額外初始化。

   static void main_loop(void)
   {
       int r;
   #ifdef CONFIG_COREMU
       /* 1. Not finish: need some initialization */
    
       /* 2. register hook functions */
       /* register the interrupt handler */
       coremu_register_event_handler((void (*)(void*))cm_common_intr_handler);
       /* register the event notifier */
       coremu_register_event_notifier(cm_notify_event);
    
       /* 3. register core alarm handler. */
       struct sigaction act;
       sigfillset(&act.sa_mask);
       act.sa_flags = 0;
       act.sa_handler = cm_local_host_alarm_handler;
       sigaction(COREMU_CORE_ALARM, &act, NULL);
    
       /* 4. Create cpu thread body*/
       coremu_run_all_cores(cm_cpu_loop);  // coremu_run_all_cores coremu/main/core.c cm_cpu_loop (qemu/cm-loop.c)
   #else
       qemu_main_loop_start();

針對客戶的 atomic 指令，COREMU 會另行處理。以 x86 為例，

1. xchg 為 atomic 指令。

       case 0x87: /* xchg Ev, Gv */
           if ((b & 1) == 0)
               ot = OT_BYTE;
           else
               ot = dflag + OT_WORD;
           modrm = ldub_code(s->pc++);
           reg = ((modrm >> 3) & 7) | rex_r;
           mod = (modrm >> 6) & 3;
           if (mod == 3) {
               rm = (modrm & 7) | REX_B(s);
           do_xchg_reg:
               gen_op_mov_TN_reg(ot, 0, reg);
               gen_op_mov_TN_reg(ot, 1, rm);
               gen_op_mov_reg_T0(ot, rm);
               gen_op_mov_reg_T1(ot, reg);
           } else {
               gen_lea_modrm(s, modrm, &reg_addr, &offset_addr);
    
   #ifdef CONFIG_COREMU
               /* for xchg, lock is implicit.
                  XXX: none flag is affected! */
               switch (ot & 3) {
               case 0:
                   gen_helper_xchgb(cpu_A0, tcg_const_i32(reg),
                           tcg_const_i32(X86_64_HREGS));
                   break;
               case 1:
                   gen_helper_xchgw(cpu_A0, tcg_const_i32(reg),
                           tcg_const_i32(X86_64_HREGS));
                   break;
               case 2:
                   gen_helper_xchgl(cpu_A0, tcg_const_i32(reg),
                           tcg_const_i32(X86_64_HREGS));
                   break;
   #ifdef TARGET_X86_64
                   case 3:
                   gen_helper_xchgq(cpu_A0, tcg_const_i32(reg),
                           tcg_const_i32(x86_64_hregs));
   #endif
               }
   #else

2. 呼叫 COREMU 自行定義的 helper function (target-i386/cm-atomic.c)。

   #define GEN_ATOMIC_XCHG(type) \
   void helper_xchg##type(target_ulong a0, int reg, int hreg)    \
   {                                                             \
       DATA_##type val, out;                                     \
       unsigned long q_addr;                                     \
                                                                 \
       CM_GET_QEMU_ADDR(q_addr, a0);                             \
       val = (DATA_##type)cm_get_reg_val(OT_##type, hreg, reg);  \
       out = atomic_exchange##type((DATA_##type *)q_addr, val);  \
       mb();                                                     \
                                                                 \
       cm_set_reg_val(OT_##type, hreg, reg, out);                \
   }

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