[U-Boot] [PATCH v8 2/8] ARM: socfpga: Add default FPGA bitstream fitImage for Arria10 SoCDK

Chee, Tien Fong tien.fong.chee at intel.com
Thu Feb 14 15:47:35 UTC 2019


On Thu, 2019-02-14 at 16:13 +0100, Marek Vasut wrote:
> On 2/14/19 4:11 PM, Chee, Tien Fong wrote:
> > 
> > On Thu, 2019-02-14 at 13:24 +0100, Marek Vasut wrote:
> > > 
> > > On 2/14/19 12:23 PM, Chee, Tien Fong wrote:
> > > > 
> > > > 
> > > > On Thu, 2019-02-14 at 11:35 +0100, Marek Vasut wrote:
> > > > > 
> > > > > 
> > > > > On 2/14/19 7:04 AM, Chee, Tien Fong wrote:
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > On Thu, 2019-02-14 at 00:04 +0100, Marek Vasut wrote:
> > > > > > > 
> > > > > > > 
> > > > > > > 
> > > > > > > On 2/13/19 11:45 PM, Dalon L Westergreen wrote:
> > > > > > > > 
> > > > > > > > 
> > > > > > > > 
> > > > > > > > 
> > > > > > > > On Wed, 2019-02-13 at 17:10 +0100, Marek Vasut wrote:
> > > > > > > > > 
> > > > > > > > > 
> > > > > > > > > 
> > > > > > > > > 
> > > > > > > > > On 2/13/19 3:18 PM, tien.fong.chee at intel.com wrote:
> > > > > > > > > > 
> > > > > > > > > > 
> > > > > > > > > > 
> > > > > > > > > > 
> > > > > > > > > > From: Tien Fong Chee <tien.fong.chee at intel.com>
> > > > > > > > > > 
> > > > > > > > > > Add default fitImage file bundling FPGA bitstreams
> > > > > > > > > > for
> > > > > > > > > > Arria10.
> > > > > > > > > > 
> > > > > > > > > > Signed-off-by: Tien Fong Chee <tien.fong.chee at intel
> > > > > > > > > > .com
> > > > > > > > > > > 
> > > > > > > > > > > 
> > > > > > > > > > ---
> > > > > > > > > > 
> > > > > > > > > > changes for v8
> > > > > > > > > > - Changed the FPGA node name to fpga-core and fpga-
> > > > > > > > > > periph
> > > > > > > > > > for
> > > > > > > > > > both core and
> > > > > > > > > >   periph bitstreams respectively.
> > > > > > > > > > ---
> > > > > > > > > >  board/altera/arria10-socdk/fit_spl_fpga.its | 39
> > > > > > > > > > +++++++++++++++++++++++++++++
> > > > > > > > > >  1 file changed, 39 insertions(+)
> > > > > > > > > >  create mode 100644 board/altera/arria10-
> > > > > > > > > > socdk/fit_spl_fpga.its
> > > > > > > > > > 
> > > > > > > > > > diff --git a/board/altera/arria10-
> > > > > > > > > > socdk/fit_spl_fpga.its
> > > > > > > > > > b/board/altera/arria10-socdk/fit_spl_fpga.its
> > > > > > > > > > new file mode 100644
> > > > > > > > > > index 0000000..8ce175b
> > > > > > > > > > --- /dev/null
> > > > > > > > > > +++ b/board/altera/arria10-socdk/fit_spl_fpga.its
> > > > > > > > > > @@ -0,0 +1,39 @@
> > > > > > > > > > +// SPDX-License-Identifier: GPL-2.0
> > > > > > > > > > + /*
> > > > > > > > > > + * Copyright (C) 2019 Intel Corporation <www.intel
> > > > > > > > > > .com
> > > > > > > > > > > 
> > > > > > > > > > > 
> > > > > > > > > > + *
> > > > > > > > > > + */
> > > > > > > > > > +
> > > > > > > > > > +/dts-v1/;
> > > > > > > > > > +
> > > > > > > > > > +/ {
> > > > > > > > > > +	description = "FIT image with FPGA
> > > > > > > > > > bistream";
> > > > > > > > > > +	#address-cells = <1>;
> > > > > > > > > > +
> > > > > > > > > > +	images {
> > > > > > > > > > +		fpga-core at 1 {
> > > > > > > > > > +			description = "FPGA core
> > > > > > > > > > bitstream";
> > > > > > > > > > +			data =
> > > > > > > > > > /incbin/("../../../ghrd_10as066n2.core.rbf");
> > > > > > > > > > +			type = "fpga";
> > > > > > > > > > +			arch = "arm";
> > > > > > > > > > +			compression = "none";
> > > > > > > > > > +			load = <0x400>;
> > > > > > > > > Is the load address required ?
> > > > > > It is optional for telling destination address of DDR where
> > > > > > this
> > > > > > core.rbf going to be loaded. If load property, the default
> > > > > > OCRAM
> > > > > > buffer
> > > > > > would be used, bad for performance when loading chunk by
> > > > > > chunk.
> > > > > So if I have something at 0x400 in DRAM and use this example
> > > > > in
> > > > > U-
> > > > > Boot,
> > > > > it will be overwritten ?
> > > > This is used for SPL only, at least for now, so that is before
> > > > loading
> > > > the U-Boot, DDR is blank.
> > > > But, you can define the blank location.
> > > > If load property is not defined, the driver would use small
> > > > buffer
> > > > from
> > > > OCRAM.
> > > > > 
> > > > > 
> > > > > 
> > > > > How is OCRAM bad for performance ?
> > > > With DDR, the performance can up to 85-90%.
> > > > It is because very limited space in OCRAM, so very small buffer
> > > > is
> > > > used
> > > > for loading bitstream, so the bitstream has to be loaded chunk
> > > > by
> > > > chunk.
> > > > For DDR, where whole bitstream can be loaded.
> > > Shouldn't the logic to determine where the buffer is be in the
> > > code ?
> > > I mean, once you have DRAM available, you have all the malloc
> > > space,
> > > so
> > > you can use larger buffer.Why encode that knowledge into the
> > > fitImage
> > > ?
> > In previosly, we hard code the dest location for loading the core
> > bitstream in SPL, because by that time DDR up running, but malloc
> > is
> > still pointed to OCRAM.
> > Now, we let user to define the dest location through the load
> > property.
> But the user shouldn't care where the buffer is, the buffer should be
> in
> the best possible location and the SPL can determine that (if DRAM is
> running, in DRAM, otherwise in OCRAM), no ?
Yes, most of the time user don't need to change the dest value at load
property, unless they have very good reason to do so.
SPL would smart enough to read the load property after the DDR is up
running, and loading the bitstream to dest location, and programming
FPGA from there.
> 


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