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Re: [Qemu-devel] [PATCH v4] nios2: Add Altera JTAG UART emulation
From: |
Bystricky, Juro |
Subject: |
Re: [Qemu-devel] [PATCH v4] nios2: Add Altera JTAG UART emulation |
Date: |
Thu, 9 Feb 2017 20:53:04 +0000 |
> On 02/09/2017 07:52 PM, Juro Bystricky wrote:
> > JTAG UART core eliminates the need for a separate RS-232 serial
> > connection to a host PC for character I/O.
>
> And how does this describe the content of this patch ? This patch adds a
> model of JTAG UART , it doesn't eliminate anything ...
>
The commit message explicitly says:
"Add Altera JTAG UART emulation."
But I will amend the message with more details.
> > Hardware emulation based on:
> > https://www.altera.com/en_US/pdfs/literature/ug/ug_embedded_ip.pdf
> > (Please see "Register Map" on page 65)
> >
> > Signed-off-by: Juro Bystricky <address@hidden>
> > ---
>
> Changelog is missing ...
I modelled this patch based on other nios2 patches, none of them contained
Changelog. So please elaborate.
> > + /*
> > + * FIFO size can be set from 8 to 32,768 bytes.
> > + * Only powers of two are allowed.
> > + */
> > + fifo_size_ok = false;
> > + for (size = 8; size <= 32768; size *= 2) {
> > + if (size == fifo_size) {
> > + fifo_size_ok = true;
> > + break;
> > + }
> > + }
>
> Isn't that like
>
> if (size < 8 || size > 32768 || (size & ~(1 << ffs(size))))
> error()
>
possibly, however ffs is rejected by checkpatch as non-portable
libc call.
> > +#define DEFAULT_FIFO_SIZE 64
>
> This is still not QOM property , why ?
>
Not sure what you mean, the code has:
DEFINE_PROP_UINT32("fifo-size", AlteraJUARTState, rx_fifo_size,
DEFAULT_FIFO_SIZE),
Thanks
Juro