[U-Boot] [PATCH v7 1/7] ARM: socfpga: Description on FPGA bitstream type and file name for Arria 10

Dalon L Westergreen
2019-02-01T20:02:35Z

On Sat, 2019-02-02 at 00:02 +0800, Chee, Tien Fong wrote:
> On Fri, 2019-02-01 at 09:25 +0100, Marek Vasut wrote:
> > On 2/1/19 4:48 AM, Chee, Tien Fong wrote:
> > > On Thu, 2019-01-31 at 15:54 +0100, Marek Vasut wrote:
> > > > On 1/31/19 3:51 PM, tien.fong.chee at intel.com wrote:
> > > > >
> > > > > From: Tien Fong Chee <tien.fong.chee@intel.com>
> > > > >
> > > > > This patch adds description on properties about file name used
> > > > > for
> > > > > both
> > > > > peripheral bitstream and core bitstream.
> > > > >
> > > > > Signed-off-by: Tien Fong Chee <tien.fong.chee@intel.com>
> > > > >
> > > > > ---
> > > > >
> > > > > changes for v7
> > > > > - Provided example of setting FPGA FIT image for both early IO
> > > > > release
> > > > > and full release FPGA configuration.
> > > > > ---
> > > > > .../fpga/altera-socfpga-a10-fpga-mgr.txt | 34
> > > > > +++++++++++++++++++++-
> > > > > 1 file changed, 33 insertions(+), 1 deletion(-)
> > > > >
> > > > > diff --git a/doc/device-tree-bindings/fpga/altera-socfpga-a10-
> > > > > fpga-
> > > > > mgr.txt b/doc/device-tree-bindings/fpga/altera-socfpga-a10-
> > > > > fpga-
> > > > > mgr.txt
> > > > > index 2fd8e7a..5f81a32 100644
> > > > > --- a/doc/device-tree-bindings/fpga/altera-socfpga-a10-fpga-
> > > > > mgr.txt
> > > > > +++ b/doc/device-tree-bindings/fpga/altera-socfpga-a10-fpga-
> > > > > mgr.txt
> > > > > @@ -7,8 +7,39 @@ Required properties:
> > > > > - The second index is for writing FPGA
> > > > > configuration data.
> > > > > - resets : Phandle and reset specifier for the device's
> > > > > reset.
> > > > > - clocks : Clocks used by the device.
> > > > > +- altr,bitstream : File name for FPGA peripheral bitstream
> > > > > which
> > > > > is used
> > > > > + to initialize FPGA IOs, PLL, IO48 and DDR.
> > > > > This
> > > > > bitstream is
> > > > > + required to get DDR up running.
> > > > > + or
> > > > > + File name for full bitstream, consist of
> > > > > peripheral bitstream
> > > > > + and core bitstream.
> > > > > +- altr,bitstream-core(optional) : File name for core bitstream
> > > > > which contains
> > > > Is the name of the property 'altr,bitstream-core(optional)' ? I
> > > > think
> > > > the "optional" part should be in the description.
> > > Yes, you are right.
> > > >
> > > > >
> > > > > + FPGA design which is used to
> > > > > program FPGA CRAM
> > > > > + and ERAM.
> > > > >
> > > > > -Example:
> > > > > +Example: Bundles both peripheral bitstream and core bitstream
> > > > > into
> > > > > FIT image
> > > > > + called fit_spl_fpga.itb. This FIT image can be
> > > > > created
> > > > > through running
> > > > > + this command: tools/mkimage
> > > > > + -E -p 400
> > > > > + -f board/altera/arria10-
> > > > > socdk/fit_spl_fpga.its
> > > > > + fit_spl_fpga.itb
> > > > > +
> > > > > + For details of describing structure and contents of
> > > > > the
> > > > > FIT image,
> > > > > + please refer board/altera/arria10-
> > > > > socdk/fit_spl_fpga.its
> > > > > +
> > > > > +- Examples for booting with early IO release, and enter early
> > > > > user
> > > > > mode:
> > > > > +
> > > > > + fpga_mgr: fpga-mgr at ffd03000 {
> > > > > + compatible = "altr,socfpga-a10-fpga-mgr";
> > > > > + reg = <0xffd03000 0x100
> > > > > + 0xffcfe400 0x20>;
> > > > > + clocks = <&l4_mp_clk>;
> > > > > + resets = <&rst FPGAMGR_RESET>;
> > > > > + altr,bitstream = "fit_spl_fpga.itb";
> > > > > + altr,bitstream-core = "fit_spl_fpga.itb";
> > > > It's the same file, why does it use two properties ?
> > > 1. Allows user to run optional for program core. When "" is set to
> > > altr,bitstream-core, then SPL would skip programming FPGA with
> > > core, so
> > > user can program it later on U-Boot or Linux.
> > You can just pass in a fitImage with only the periph image in it in
> > such
> > a case.
> What if user want to program the core on U-Boot? User need to create
> two FIT images, one FIT with periph image, and another FIT with core
> image only.
>
> Current implementation supports one FIT image for above configuration.
> > > 2. Allows core in different FIT file.
> > Is this really useful ?
> Yes, for the use case which support different core image for different
> revision of board but using same periph image.

I would have to disagree here. This is not a supported flow, the periph image
and core image must come from the same compilation of quartus for arria10 to
guarantee functionality. That is unless something has changed that I am not
aware of? I believe this holds true in S10, the difference being that in s10
you can reconfigure the periph rbf without affecting the processor IO.

Why are there separate fit images for uboot and the fpga? would it not
make sense to combine them into a single fit image? Wouldn't you want to
couple a devicetree and a periph image together and then allow for
selection of configurations?

I also wonder why there is a need to support core image programming
in SPL? If the desire is to have the full image programmed, would
you not just create a single rbf (combined periph and core?)

--dalon

> > > > And where is this
> > > > file loaded from ?
> > > You need to set the default source in DTS, for example "firmware-
> > > loader
> > > = &fs_loader0", that's for power boot up purpose. After that,
> > > generic
> > > firmware loader would go to the dsignated storage as described
> > > below to
> > > find the FPGA FIT image according description from above.
> > >
> > > fs_loader0: fs-loader at 0 {
> > > u-boot,dm-pre-reloc;
> > > compatible = "u-boot,fs-loader";
> > > phandlepart = <&mmc 1>;
> > > };
> > How does the driver bound to fpga-mgr know which firmware loader
> > instance to use ? There's no phandle.
> Current firmware loader supports only one instance, that is default
> instance described in chosen node. It is good enough to solve our
> problem where to define a default storage for FPGA images and how to
> tell the SPL to load it from the default storage when the board is
> powered up. I don't see there is a need to support more than one
> instance for fpga-mgr during SPL runtime, at least for now. User can
> program the FPGA with core image from any storage with series of
> commands such as fatload and socfpga load on U-Boot console.
>
> It is good to improve the firmware loader to support
> the DM_FLAG_PRE_RELOC, which allow user to choose different firmware
> loader node through setting the right sequence number when creating the
> firmare loader instance in the parent driver such as fpga mgr, but i
> don't see there is urgency need to be done now.
> > > > > + };
> > > > > +
> > > > > +- Examples for booting with full release, enter user mode with
> > > > > full bitstream:
> > > > >
> > > > > fpga_mgr: fpga-mgr at ffd03000 {
> > > > > compatible = "altr,socfpga-a10-fpga-mgr";
> > > > > @@ -16,4 +47,5 @@ Example:
> > > > > 0xffcfe400 0x20>;
> > > > > clocks = <&l4_mp_clk>;
> > > > > resets = <&rst FPGAMGR_RESET>;
> > > > > + altr,bitstream = "fit_spl_fpga.itb";
> > > > > };
> > > > >