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Date: Fri, 04 Apr 2014 08:33:21 -0500
From: Tom Musta <tommusta@gmail.com>
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Subject: Re: [Qemu-devel] [PATCH v7] target-ppc: gdbstub allow byte swapping
 for reading/writing registers
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To: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>, qemu-devel@nongnu.org
Cc: qemu-ppc@nongnu.org, agraf@suse.de

On 4/1/2014 3:03 PM, Thomas Falcon wrote:
> This patch allows registers to be properly read from and written to
> when using the gdbstub to debug a ppc guest running in little
> endian mode.  It accomplishes this goal by byte swapping the values of
> any registers if the MSR:LE value is set.
> 
> Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>

<snip>

> index 1c91090..92649ed 100644
> --- a/target-ppc/gdbstub.c
> +++ b/target-ppc/gdbstub.c
> @@ -21,6 +21,82 @@
>  #include "qemu-common.h"
>  #include "exec/gdbstub.h"
>  
> +static int ppc_cpu_gdb_register_len(int n)
> +{
> +    switch (n) {
> +    case 0 ... 31:
> +        /* gprs */
> +        return sizeof(target_ulong);
> +    case 32 ... 63:
> +        /* fprs */
> +        if (gdb_has_xml) {
> +            return 0;
> +        }
> +        return 8;

The magic numbers in the case statement are not ideal but there is
precedent in the code already for this.

Reviewed-by: Tom Musta <tommusta@gmail.com>
Tested-by: Tom Musta <tommusta@gmail.com>