Re: [PATCH V2 2/4] target/microblaze: gdb: Extend the number of registers presented to GDB

["Edgar E. Iglesias" <edgar.iglesias@xilinx.com>]

On Wed, May 13, 2020 at 11:08:46AM -0700, Joe Komlodi wrote:
> Increase the number of Microblaze registers QEMU will report when
> talking to GDB.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>


> 
> Signed-off-by: Joe Komlodi <komlodi@xilinx.com>
> ---
>  target/microblaze/cpu.c     |  2 +-
>  target/microblaze/gdbstub.c | 52 ++++++++++++++++++++++++++++++++++++++++++---
>  2 files changed, 50 insertions(+), 4 deletions(-)
> 
> diff --git a/target/microblaze/cpu.c b/target/microblaze/cpu.c
> index 41cac1b..5b6ad5b 100644
> --- a/target/microblaze/cpu.c
> +++ b/target/microblaze/cpu.c
> @@ -331,7 +331,7 @@ static void mb_cpu_class_init(ObjectClass *oc, void *data)
>  #endif
>      dc->vmsd = &vmstate_mb_cpu;
>      device_class_set_props(dc, mb_properties);
> -    cc->gdb_num_core_regs = 32 + 5;
> +    cc->gdb_num_core_regs = 32 + 27;
>      cc->gdb_get_dynamic_xml = mb_gdb_get_dynamic_xml;
>      cc->gdb_core_xml_file = "microblaze-core.xml";
>  
> diff --git a/target/microblaze/gdbstub.c b/target/microblaze/gdbstub.c
> index cdca434..af29f00 100644
> --- a/target/microblaze/gdbstub.c
> +++ b/target/microblaze/gdbstub.c
> @@ -26,12 +26,37 @@ int mb_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
>      MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
>      CPUMBState *env = &cpu->env;
>  
> +    /*
> +     * GDB expects registers to be reported in this order:
> +     * R0-R31
> +     * PC-BTR
> +     * PVR0-PVR11
> +     * EDR-TLBHI
> +     * SLR-SHR
> +     */
>      if (n < 32) {
>          return gdb_get_reg32(mem_buf, env->regs[n]);
>      } else {
> -        return gdb_get_reg32(mem_buf, env->sregs[n - 32]);
> +        n -= 32;
> +        switch (n) {
> +        case 0 ... 5:
> +            return gdb_get_reg32(mem_buf, env->sregs[n]);
> +        /* PVR12 is intentionally skipped */
> +        case 6 ... 17:
> +            n -= 6;
> +            return gdb_get_reg32(mem_buf, env->pvr.regs[n]);
> +        case 18 ... 24:
> +            /* Add an offset of 6 to resume where we left off with SRegs */
> +            n = n - 18 + 6;
> +            return gdb_get_reg32(mem_buf, env->sregs[n]);
> +        case 25:
> +            return gdb_get_reg32(mem_buf, env->slr);
> +        case 26:
> +            return gdb_get_reg32(mem_buf, env->shr);
> +        default:
> +            return 0;
> +        }
>      }
> -    return 0;
>  }
>  
>  int mb_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
> @@ -50,7 +75,28 @@ int mb_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
>      if (n < 32) {
>          env->regs[n] = tmp;
>      } else {
> -        env->sregs[n - 32] = tmp;
> +        n -= 32;
> +        switch (n) {
> +        case 0 ... 5:
> +            env->sregs[n] = tmp;
> +            break;
> +        /* PVR12 is intentionally skipped */
> +        case 6 ... 17:
> +            n -= 6;
> +            env->pvr.regs[n] = tmp;
> +            break;
> +        case 18 ... 24:
> +            /* Add an offset of 6 to resume where we left off with SRegs */
> +            n = n - 18 + 6;
> +            env->sregs[n] = tmp;
> +            break;
> +        case 25:
> +            env->slr = tmp;
> +            break;
> +        case 26:
> +            env->shr = tmp;
> +            break;
> +        }
>      }
>      return 4;
>  }
> -- 
> 2.7.4
>