On Sunday, December 8, 2019, Michael Rolnik <mrolnik@gmail.com> wrote:

> Provide function disassembles executed instruction when `-d in_asm` is
> provided
>
> Example:
> `./avr-softmmu/qemu-system-avr -bios free-rtos/Demo/AVR_ATMega2560_GCC/demo.elf
> -d in_asm` will produce something like the following
>
> ```
>     ...
>     IN:
>     0x0000014a:  CALL      0x3808
>
>     IN: main
>     0x00003808:  CALL      0x4b4
>
>     IN: vParTestInitialise
>     0x000004b4:  LDI       r24, 255
>     0x000004b6:  STS       r24, 0
>     0x000004b8:  MULS      r16, r20
>     0x000004ba:  OUT       $1, r24
>     0x000004bc:  LDS       r24, 0
>     0x000004be:  MULS      r16, r20
>     0x000004c0:  OUT       $2, r24
>     0x000004c2:  RET
>     ...
> ```
>
> Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Suggested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  target/avr/cpu.h       |   1 +
>  target/avr/cpu.c       |   2 +-
>  target/avr/disas.c     | 226 +++++++++++++++++++++++++++++++++++++++++
>  target/avr/translate.c |  11 ++
>  4 files changed, 239 insertions(+), 1 deletion(-)
>  create mode 100644 target/avr/disas.c
>
> diff --git a/target/avr/cpu.h b/target/avr/cpu.h
> index c217eefeb4..a8a3e7ade6 100644
> --- a/target/avr/cpu.h
> +++ b/target/avr/cpu.h
> @@ -178,6 +178,7 @@ bool avr_cpu_exec_interrupt(CPUState *cpu, int
> int_req);
>  hwaddr avr_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
>  int avr_cpu_gdb_read_register(CPUState *cpu, uint8_t *buf, int reg);
>  int avr_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
> +int avr_print_insn(bfd_vma addr, disassemble_info *info);
>
>  static inline int avr_feature(CPUAVRState *env, int feature)
>  {
> diff --git a/target/avr/cpu.c b/target/avr/cpu.c
> index c5cafcae3c..be4b921e4d 100644
> --- a/target/avr/cpu.c
> +++ b/target/avr/cpu.c
> @@ -83,7 +83,7 @@ static void avr_cpu_reset(CPUState *cs)
>  static void avr_cpu_disas_set_info(CPUState *cpu, disassemble_info *info)
>  {
>      info->mach = bfd_arch_avr;
> -    info->print_insn = NULL;
> +    info->print_insn = avr_print_insn;
>  }
>
>  static void avr_cpu_realizefn(DeviceState *dev, Error **errp)
> diff --git a/target/avr/disas.c b/target/avr/disas.c
> new file mode 100644
> index 0000000000..22863d2eb1
> --- /dev/null
> +++ b/target/avr/disas.c
> @@ -0,0 +1,226 @@
> +/*
> + * AVR disassembler
> + *
> + * Copyright (c) 2019 Richard Henderson <rth@twiddle.net>
> + * Copyright (c) 2019 Michael Rolnik <mrolnik@gmail.com>
> + *
> + * 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 "qemu/osdep.h"
> +#include "cpu.h"
> +
> +typedef struct {
> +    disassemble_info *info;
> +    uint16_t next_word;
> +    bool next_word_used;
> +} DisasContext;
> +
> +static int to_regs_16_31_by_one(DisasContext *ctx, int indx)
> +{
> +    return 16 + (indx % 16);
> +}
> +
> +static int to_regs_16_23_by_one(DisasContext *ctx, int indx)
> +{
> +    return 16 + (indx % 8);
> +}
> +static int to_regs_24_30_by_two(DisasContext *ctx, int indx)
> +{
> +    return 24 + (indx % 4) * 2;
> +}
> +static int to_regs_00_30_by_two(DisasContext *ctx, int indx)
> +{
> +    return (indx % 16) * 2;
> +}
> +
> +static uint16_t next_word(DisasContext *ctx)
> +{
> +    ctx->next_word_used = true;
> +    return ctx->next_word;
> +}
> +
> +static int append_16(DisasContext *ctx, int x)
> +{
> +    return x << 16 | next_word(ctx);
> +}
> +
> +
> +/* Include the auto-generated decoder.  */
> +static bool decode_insn(DisasContext *ctx, uint16_t insn);
> +#include "decode_insn.inc.c"
> +
> +#define output(mnemonic, format, ...) \
> +    (pctx->info->fprintf_func(pctx->info->stream, "%-9s " format, \
> +                        mnemonic, ##__VA_ARGS__))
> +
> +int avr_print_insn(bfd_vma addr, disassemble_info *info)
> +{
> +    DisasContext ctx;
> +    DisasContext *pctx = &ctx;
> +    bfd_byte buffer[4];
> +    uint16_t insn;
> +    int status;
> +
> +    ctx.info = info;
> +
> +    status = info->read_memory_func(addr, buffer, 4, info);
> +    if (status != 0) {
> +        info->memory_error_func(status, addr, info);
> +        return -1;
> +    }
> +    insn = bfd_getl16(buffer);
> +    ctx.next_word = bfd_getl16(buffer + 2);
> +    ctx.next_word_used = false;
> +
> +    if (!decode_insn(&ctx, insn)) {
> +        output(".db", "0x%02x, 0x%02x", buffer[0], buffer[1]);
> +    }
> +
> +    return ctx.next_word_used ? 4 : 2;
> +}


Hi, Michael,

What is the role of ctx.next_word_used, if it looks it is always "false"?

Related to this, how do you disassemble 32-bit-coded instructions? From
this patch, it looks you treat all AVR instructions as 16-bit-coded?

Thanks,
Aleksandar


> +
> +
> +#define INSN(opcode, format, ...)                                       \
> +static bool trans_##opcode(DisasContext *pctx, arg_##opcode * a)        \
> +{                                                                       \
> +    output(#opcode, format, ##__VA_ARGS__);                             \
> +    return true;                                                        \
> +}
> +
> +#define INSN_MNEMONIC(opcode, mnemonic, format, ...)                    \
> +static bool trans_##opcode(DisasContext *pctx, arg_##opcode * a)        \
> +{                                                                       \
> +    output(mnemonic, format, ##__VA_ARGS__);                            \
> +    return true;                                                        \
> +}
> +
> +/*
> + *   C       Z       N       V       S       H       T       I
> + *   0       1       2       3       4       5       6       7
> + */
> +static const char *brbc[] = {
> +    "BRCC", "BRNE", "BRPL", "BRVC", "BRGE", "BRHC", "BRTC", "BRID"
> +};
> +
> +static const char *brbs[] = {
> +    "BRCS", "BREQ", "BRMI", "BRVS", "BRLT", "BRHS", "BRTS", "BRIE"
> +};
> +
> +static const char *bset[] = {
> +    "SEC",  "SEZ",  "SEN",  "SEZ",  "SES",  "SEH",  "SET",  "SEI"
> +};
> +
> +static const char *bclr[] = {
> +    "CLC",  "CLZ",  "CLN",  "CLZ",  "CLS",  "CLH",  "CLT",  "CLI"
> +};
> +
> +INSN(ADC,    "r%d, r%d", a->rd, a->rr)
> +INSN(ADD,    "r%d, r%d", a->rd, a->rr)
> +INSN(ADIW,   "r%d:r%d, %d", a->rd + 1, a->rd, a->imm)
> +INSN(AND,    "r%d, r%d", a->rd, a->rr)
> +INSN(ANDI,   "r%d, %d", a->rd, a->imm)
> +INSN(ASR,    "r%d", a->rd)
> +INSN_MNEMONIC(BCLR,  bclr[a->bit], "")
> +INSN(BLD,    "r%d, %d", a->rd, a->bit)
> +INSN_MNEMONIC(BRBC,  brbc[a->bit], ".%+d", a->imm * 2)
> +INSN_MNEMONIC(BRBS,  brbs[a->bit], ".%+d", a->imm * 2)
> +INSN(BREAK,  "")
> +INSN_MNEMONIC(BSET,  bset[a->bit], "")
> +INSN(BST,    "r%d, %d", a->rd, a->bit)
> +INSN(CALL,   "0x%x", a->imm * 2)
> +INSN(CBI,    "%d, %d", a->reg, a->bit)
> +INSN(COM,    "r%d", a->rd)
> +INSN(CP,     "r%d, r%d", a->rd, a->rr)
> +INSN(CPC,    "r%d, r%d", a->rd, a->rr)
> +INSN(CPI,    "r%d, %d", a->rd, a->imm)
> +INSN(CPSE,   "r%d, r%d", a->rd, a->rr)
> +INSN(DEC,    "r%d", a->rd)
> +INSN(DES,    "%d", a->imm)
> +INSN(EICALL, "")
> +INSN(EIJMP,  "")
> +INSN(ELPM1,  "")
> +INSN(ELPM2,  "r%d, Z", a->rd)
> +INSN(ELPMX,  "r%d, Z+", a->rd)
> +INSN(EOR,    "r%d, r%d", a->rd, a->rr)
> +INSN(FMUL,   "r%d, r%d", a->rd, a->rr)
> +INSN(FMULS,  "r%d, r%d", a->rd, a->rr)
> +INSN(FMULSU, "r%d, r%d", a->rd, a->rr)
> +INSN(ICALL,  "")
> +INSN(IJMP,   "")
> +INSN(IN,     "r%d, $%d", a->rd, a->imm)
> +INSN(INC,    "r%d", a->rd)
> +INSN(JMP,    "0x%x", a->imm * 2)
> +INSN(LAC,    "Z, r%d", a->rd)
> +INSN(LAS,    "Z, r%d", a->rd)
> +INSN(LAT,    "Z, r%d", a->rd)
> +INSN(LDDY,   "r%d, Y+%d", a->rd, a->imm)
> +INSN(LDDZ,   "r%d, Z+%d", a->rd, a->imm)
> +INSN(LDI,    "r%d, %d", a->rd, a->imm)
> +INSN(LDS,    "r%d, %d", a->rd, a->imm)
> +INSN(LDX1,   "r%d, X", a->rd)
> +INSN(LDX2,   "r%d, X+", a->rd)
> +INSN(LDX3,   "r%d, -X", a->rd)
> +INSN(LDY2,   "r%d, Y+", a->rd)
> +INSN(LDY3,   "r%d, -Y", a->rd)
> +INSN(LDZ2,   "r%d, Z+", a->rd)
> +INSN(LDZ3,   "r%d, -Z", a->rd)
> +INSN(LPM1,   "")
> +INSN(LPM2,   "r%d, Z", a->rd)
> +INSN(LPMX,   "r%d, Z+", a->rd)
> +INSN(LSR,    "r%d", a->rd)
> +INSN(MOV,    "r%d, r%d", a->rd, a->rr)
> +INSN(MOVW,   "r%d:r%d, r%d,r:r%d", a->rd + 1, a->rd, a->rr + 1, a->rr)
> +INSN(MUL,    "r%d, r%d", a->rd, a->rr)
> +INSN(MULS,   "r%d, r%d", a->rd, a->rr)
> +INSN(MULSU,  "r%d, r%d", a->rd, a->rr)
> +INSN(NEG,    "r%d", a->rd)
> +INSN(NOP,    "")
> +INSN(OR,     "r%d, r%d", a->rd, a->rr)
> +INSN(ORI,    "r%d, %d", a->rd, a->imm)
> +INSN(OUT,    "$%d, r%d", a->imm, a->rd)
> +INSN(POP,    "r%d", a->rd)
> +INSN(PUSH,   "r%d", a->rd)
> +INSN(RCALL,  ".%+d", a->imm * 2)
> +INSN(RET,    "")
> +INSN(RETI,   "")
> +INSN(RJMP,   ".%+d", a->imm * 2)
> +INSN(ROR,    "r%d", a->rd)
> +INSN(SBC,    "r%d, r%d", a->rd, a->rr)
> +INSN(SBCI,   "r%d, %d", a->rd, a->imm)
> +INSN(SBI,    "$%d, %d", a->reg, a->bit)
> +INSN(SBIC,   "$%d, %d", a->reg, a->bit)
> +INSN(SBIS,   "$%d, %d", a->reg, a->bit)
> +INSN(SBIW,   "r%d:r%d, %d", a->rd + 1, a->rd, a->imm)
> +INSN(SBRC,   "r%d, %d", a->rr, a->bit)
> +INSN(SBRS,   "r%d, %d", a->rr, a->bit)
> +INSN(SLEEP,  "")
> +INSN(SPM,    "")
> +INSN(SPMX,   "Z+")
> +INSN(STDY,   "r%d, Y+%d", a->rd, a->imm)
> +INSN(STDZ,   "r%d, Z+%d", a->rd, a->imm)
> +INSN(STS,    "r%d, %d", a->rd, a->imm)
> +INSN(STX1,   "r%d, X", a->rr)
> +INSN(STX2,   "r%d, X+", a->rr)
> +INSN(STX3,   "r%d, -X", a->rr)
> +INSN(STY2,   "r%d, Y+", a->rd)
> +INSN(STY3,   "r%d, -Y", a->rd)
> +INSN(STZ2,   "r%d, Z+", a->rd)
> +INSN(STZ3,   "r%d, -Z", a->rd)
> +INSN(SUB,    "r%d, r%d", a->rd, a->rr)
> +INSN(SUBI,   "r%d, %d", a->rd, a->imm)
> +INSN(SWAP,   "r%d", a->rd)
> +INSN(WDR,    "")
> +INSN(XCH,    "Z, r%d", a->rd)
> +
> diff --git a/target/avr/translate.c b/target/avr/translate.c
> index c8c6f798bf..a621195817 100644
> --- a/target/avr/translate.c
> +++ b/target/avr/translate.c
> @@ -2917,6 +2917,17 @@ done_generating:
>
>      tb->size = (ctx.npc - pc_start) * 2;
>      tb->icount = num_insns;
> +
> +#ifdef DEBUG_DISAS
> +    if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)
> +        && qemu_log_in_addr_range(tb->pc)) {
> +        qemu_log_lock();
> +        qemu_log("IN: %s\n", lookup_symbol(tb->pc));
> +        log_target_disas(cs, tb->pc, tb->size);
> +        qemu_log("\n");
> +        qemu_log_unlock();
> +    }
> +#endif
>  }
>
>  void restore_state_to_opc(CPUAVRState *env, TranslationBlock *tb,
> --
> 2.17.2 (Apple Git-113)
>
>