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Re: [Qemu-devel] Endian control register
From: |
Benjamin Herrenschmidt |
Subject: |
Re: [Qemu-devel] Endian control register |
Date: |
Mon, 23 Jun 2014 13:32:27 +1000 |
On Mon, 2014-06-23 at 10:45 +1000, Benjamin Herrenschmidt wrote:
>
> Another option would be to use an unused bit if the ENABLE register
> and simply force it to 1 on reads when the endian control register
> is present... though in this case it might be a better idea to use
> that bit to indicate the presence of "extended flags", use a new
> register 0xb as "EXTENDED_FLAGS", and use a flag in there as indicative
> of the presence of endian control which becomes register 0xc.
>
> That way you also have room for more extensions if you wish to do
> so in the future.
I just remembered... we use 16-bit wide ports, we could just use the
top 8 bits of the enable register as "capabilities" ...
Cheers,
Ben.