Commit 999b53ec authored by Claudio Fontana's avatar Claudio Fontana Committed by Peter Maydell
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disas: Implement disassembly output for A64 



Use libvixl to implement disassembly output in debug
logs for A64, for use with both AArch64 hosts and targets.

Signed-off-by: default avatarClaudio Fontana <claudio.fontana@linaro.org>
[PMM:
 * added support for target disassembly
 * switched to custom QEMUDisassembler so the output format
   matches what QEMU expects
 * make sure we correctly fall back to "just print hex"
   if we didn't build the AArch64 disassembler because of
   lack of a C++ compiler
 * rename from 'aarch64' to 'arm-a64' because this is a
   disassembler for the A64 instruction set
 * merge aarch64.c and aarch64-cxx.cc into one C++ file
 * simplify the aarch64.c<->aarch64-cxx.cc interface]
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent 37fd5b53

configure

+4 −0
Original line number Diff line number Diff line
@@ -4641,6 +4641,10 @@ for i in $ARCH $TARGET_BASE_ARCH ; do 
  arm)

    echo "CONFIG_ARM_DIS=y"  >> $config_target_mak

    echo "CONFIG_ARM_DIS=y"  >> config-all-disas.mak

    if test -n "${cxx}"; then

      echo "CONFIG_ARM_A64_DIS=y"  >> $config_target_mak

      echo "CONFIG_ARM_A64_DIS=y"  >> config-all-disas.mak

    fi

  ;;

  cris)

    echo "CONFIG_CRIS_DIS=y"  >> $config_target_mak

disas.c

+12 −2
Original line number Diff line number Diff line
@@ -190,7 +190,7 @@ static int print_insn_od_target(bfd_vma pc, disassemble_info *info) 
/* Disassemble this for me please... (debugging). 'flags' has the following

   values:

    i386 - 1 means 16 bit code, 2 means 64 bit code

    arm  - bit 0 = thumb, bit 1 = reverse endian

    arm  - bit 0 = thumb, bit 1 = reverse endian, bit 2 = A64

    ppc  - nonzero means little endian

    other targets - unused

 */
@@ -225,7 +225,15 @@ void target_disas(FILE *out, CPUArchState *env, target_ulong code, 
    }

    print_insn = print_insn_i386;

#elif defined(TARGET_ARM)

    if (flags & 1) {

    if (flags & 4) {

        /* We might not be compiled with the A64 disassembler

         * because it needs a C++ compiler; in that case we will

         * fall through to the default print_insn_od case.

         */

#if defined(CONFIG_ARM_A64_DIS)

        print_insn = print_insn_arm_a64;

#endif

    } else if (flags & 1) {

        print_insn = print_insn_thumb1;

    } else {

        print_insn = print_insn_arm;
@@ -356,6 +364,8 @@ void disas(FILE *out, void *code, unsigned long size) 
#elif defined(_ARCH_PPC)

    s.info.disassembler_options = (char *)"any";

    print_insn = print_insn_ppc;

#elif defined(__aarch64__) && defined(CONFIG_ARM_A64_DIS)

    print_insn = print_insn_arm_a64;

#elif defined(__alpha__)

    print_insn = print_insn_alpha;

#elif defined(__sparc__)

disas/Makefile.objs

+5 −0
Original line number Diff line number Diff line 


common-obj-$(CONFIG_ALPHA_DIS) += alpha.o

common-obj-$(CONFIG_ARM_DIS) += arm.o

common-obj-$(CONFIG_ARM_A64_DIS) += arm-a64.o

common-obj-$(CONFIG_ARM_A64_DIS) += libvixl/

libvixldir = $(SRC_PATH)/disas/libvixl

$(obj)/arm-a64.o: QEMU_CFLAGS += -I$(libvixldir)

common-obj-$(CONFIG_CRIS_DIS) += cris.o

common-obj-$(CONFIG_HPPA_DIS) += hppa.o

common-obj-$(CONFIG_I386_DIS) += i386.o

disas/arm-a64.cc

0 → 100644
+87 −0
Original line number Diff line number Diff line 
/*

 * ARM A64 disassembly output wrapper to libvixl

 * Copyright (c) 2013 Linaro Limited

 * Written by Claudio Fontana

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */



#include "a64/disasm-a64.h"



extern "C" {

#include "disas/bfd.h"

}



using namespace vixl;



static Decoder *vixl_decoder = NULL;

static Disassembler *vixl_disasm = NULL;



/* We don't use libvixl's PrintDisassembler because its output

 * is a little unhelpful (trailing newlines, for example).

 * Instead we use our own very similar variant so we have

 * control over the format.

 */

class QEMUDisassembler : public Disassembler {

public:

    explicit QEMUDisassembler(FILE *stream) : stream_(stream) { }

    ~QEMUDisassembler() { }



protected:

    void ProcessOutput(Instruction *instr) {

        fprintf(stream_, "%08" PRIx32 "      %s",

                instr->InstructionBits(), GetOutput());

    }



private:

    FILE *stream_;

};



static int vixl_is_initialized(void)

{

    return vixl_decoder != NULL;

}



static void vixl_init(FILE *f) {

    vixl_decoder = new Decoder();

    vixl_disasm = new QEMUDisassembler(f);

    vixl_decoder->AppendVisitor(vixl_disasm);

}



#define INSN_SIZE 4



/* Disassemble ARM A64 instruction. This is our only entry

 * point from QEMU's C code.

 */

int print_insn_arm_a64(uint64_t addr, disassemble_info *info)

{

    uint8_t bytes[INSN_SIZE];

    uint32_t instr;

    int status;



    status = info->read_memory_func(addr, bytes, INSN_SIZE, info);

    if (status != 0) {

        info->memory_error_func(status, addr, info);

        return -1;

    }



    if (!vixl_is_initialized()) {

        vixl_init(info->stream);

    }



    instr = bytes[0] | bytes[1] << 8 | bytes[2] << 16 | bytes[3] << 24;

    vixl_decoder->Decode(reinterpret_cast<Instruction*>(&instr));



    return INSN_SIZE;

}

disas/libvixl/Makefile.objs

0 → 100644
+8 −0
Original line number Diff line number Diff line 
libvixl_OBJS = utils.o \

               a64/instructions-a64.o \

               a64/decoder-a64.o \

               a64/disasm-a64.o



$(addprefix $(obj)/,$(libvixl_OBJS)): QEMU_CFLAGS += -I$(SRC_PATH)/disas/libvixl



common-obj-$(CONFIG_ARM_A64_DIS) += $(libvixl_OBJS)