[U-Boot-Users] FPGA loading question

[Ben Warren <bwarren@qstreams.com>]

E Robertson wrote:
> On 9/27/07, Stefan Roese <sr@denx.de> wrote:
>   
>> Hi Matthias,
>>
>> On Thursday 27 September 2007, Matthias Fuchs wrote:
>>     
>>> What kind of CPU are you using? Please note that 4xx U-Boot ports have
>>> the cache disabled. Without cache booting a Spartan 3E in SS-mode
>>> may take very very :-(
>>>       
>> Only 44x have cache disabled. 40x has icache enabled.
>>
>> BTW: I'm still waiting for the patch to enable the cache on 44x systems... ;)
>>
>> Viele Gr??e,
>> Stefan
>>     
>
> I'm using an NXP ARM9 'A404 and can disable cache on my platform.  Due
> to my hardware fool-up, I'll have to use a bit banging method.
> I'm also concern about loading error and recovery and I'm considering
> instead to do the programming in the kernel. If there is a problem for
> some reason and the FPGA needs to be reloaded, I'll have to do it in
> the kernel anyway.
> I'm  not sure about embedding a bin file in the kernel driver either
> but It's worth pursuing.
>   
If your design can wait until Linux is booted before programming the 
FPGA, you have a world of possibilities available.  In my designs, I 
have a simple char driver with a 'write' method that bit-bangs the image 
in.  This way you can keep your image as a file in the file system and 
can add whatever encryption, wrapper or whatever your heart desires.  It 
makes trying different FPGA images a breeze.

regards,
Ben