Trouble with SCC UART ports when moving from ppc to powerpc
Scott Wood
scottwood at freescale.com
Fri Mar 21 03:24:40 EST 2008
On Thu, Mar 20, 2008 at 04:18:26PM +0100, Laurent Pinchart wrote:
> I don't want to kill it either. What I meant is that my first patch will not
> care about udbg so that I can get feedback about the CPM serial driver part.
> I'll then see how to make udbg fit into that.
OK.
> > Perhaps we should stick more initialization into the cpm udbg code, so it
> > isn't so dependent on the bootloader setup... though we'd have push the
> > CPM reset and SMC allocation earlier in such a case.
>
> When SMC1 is used as a serial console, SMC1 is the first CPM dpram
> allocation user.
Typically yes, but I wouldn't want to depend on that...
> This means the CPM dpram allocator will allocate a buffer at the beginning
> of the dpram. As he SMC controller will already be using the 64 first
> bytes of the dpram, it will not see any difference when being
> reinitialized.
Not always. Planetcore, for example, puts SMC parameter RAM at 0x1100
rather than zero.
> This of course depends on the boot loader allocating parameter ram at the
> beginning of the dpram for SMC1, but we already depend on that if I'm not
> mistaken.
We don't depend on it -- it's specified in the smc node's reg property, and
in the absence of said regions in the muram node.
-Scott
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