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Date: Thu, 08 May 2014 15:44:44 +0100
From: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
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Subject: Re: [Qemu-devel] [PATCHv3 1/2] sun4m: Add Sun CG3 framebuffer and
 corresponding OpenBIOS FCode ROM
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>, qemu-devel@nongnu.org, Blue Swirl <blauwirbel@gmail.com>, Bob Breuer <breuerr@mc.net>, Anthony Liguori <aliguori@amazon.com>, Artyom Tarasenko <atar4qemu@gmail.com>

On 07/05/14 20:56, Paolo Bonzini wrote:

> Il 05/03/2014 11:05, Paolo Bonzini ha scritto:
>> Il 19/02/2014 10:05, Mark Cave-Ayland ha scritto:
>>> +#define CG3_REG_SIZE            0x20
>>> +
>>> +#define CG3_REG_FBC_CTRL        0x10
>>> +#define CG3_REG_FBC_STATUS      0x11
>>> +#define CG3_REG_FBC_CURSTART    0x12
>>> +#define CG3_REG_FBC_CUREND      0x13
>>> +#define CG3_REG_FBC_VCTRL       0x14
>>> +
>>> +typedef struct CG3State {
>> ...
>>
>>> +    uint8_t regs[16];
>>
>> ...
>>
>>> +    case CG3_REG_FBC_CURSTART ... CG3_REG_SIZE:
>>> +        val = s->regs[addr - 0x10];
>>> +        break;
>>> +    default:
>>
>> Something weird here, you can access regs[16] if addr == CG3_REG_SIZE.
>>
>> The same happens in the write path.
>
> Ping.  I cannot fix it without access to the datasheet, though I suspect
> you want CG3_REG_SIZE - 1.

Hi Paolo,

Sorry I didn't think you could access regs[16] since the MemoryRegion 
size is set to CG3_REG_SIZE too (and so I hope should only handle 
accesses from 0 to CG3_REG_SIZE - 1).

Anyway, I've quickly tried a Solaris 8 boot test replacing CG3_REG_SIZE 
with CG3_REG_SIZE - 1 for the case statements in both the read and write 
paths and everything still works, so happy for you to go ahead and fix it.


ATB,

Mark.