Re: [Qemu-devel] [PATCH 1/3] target-arm: Implement dummy MDCCINT_EL1

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

On Thu, Oct 06, 2016 at 02:21:05PM +0100, Peter Maydell wrote:
> MDCCINT_EL1 is part of the DCC debugger communication
> channel between the CPU and an attached external debugger.
> QEMU doesn't implement this, but since Linux may try
> to access this register we need to provide at least
> a dummy implementation.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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


> ---
>  target-arm/helper.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/target-arm/helper.c b/target-arm/helper.c
> index 25f612d..23792ab 100644
> --- a/target-arm/helper.c
> +++ b/target-arm/helper.c
> @@ -4060,6 +4060,14 @@ static const ARMCPRegInfo debug_cp_reginfo[] = {
>        .cp = 14, .opc1 = 0, .crn = 0, .crm = 7, .opc2 = 0,
>        .access = PL1_RW, .accessfn = access_tda,
>        .type = ARM_CP_NOP },
> +    /* Dummy MDCCINT_EL1, since we don't implement the Debug Communications
> +     * Channel but Linux may try to access this register. The 32-bit
> +     * alias is DBGDCCINT.
> +     */
> +    { .name = "MDCCINT_EL1", .state = ARM_CP_STATE_BOTH,
> +      .cp = 14, .opc0 = 2, .opc1 = 0, .crn = 0, .crm = 2, .opc2 = 0,
> +      .access = PL1_RW, .accessfn = access_tda,
> +      .type = ARM_CP_NOP },
>      REGINFO_SENTINEL
>  };
>  
> -- 
> 2.7.4
>