[U-Boot] [PATCH 3/6] ARM: socfpga: Add the configuration for FPGA SoCFPGA A10 SoCDK

[Chee, Tien Fong <tien.fong.chee@intel.com>]

On Thu, 2019-01-03 at 21:15 +0100, Marek Vasut wrote:
> On 1/3/19 6:36 AM, Chee, Tien Fong wrote:
> > 
> > On Tue, 2019-01-01 at 21:29 +0100, Marek Vasut wrote:
> > > 
> > > On 1/1/19 4:32 AM, Chee, Tien Fong wrote:
> > > > 
> > > > 
> > > > On Sun, 2018-12-30 at 16:47 +0100, Marek Vasut wrote:
> > > > > 
> > > > > 
> > > > > On 12/30/18 9:13 AM, tien.fong.chee at intel.com wrote:
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > From: Tien Fong Chee <tien.fong.chee@intel.com>
> > > > > > 
> > > > > > Update the default configuration file to enable the
> > > > > > necessary
> > > > > > functionality
> > > > > > to get the SoCFPGA loadfs driver support. This would enable
> > > > > > the
> > > > > > implementation of programming bitstream into FPGA from MMC.
> > > > > > 
> > > > > > Signed-off-by: Tien Fong Chee <tien.fong.chee@intel.com>
> > > > > > ---
> > > > > >  configs/socfpga_arria10_defconfig |    8 ++++++++
> > > > > >  1 files changed, 8 insertions(+), 0 deletions(-)
> > > > > > 
> > > > > > diff --git a/configs/socfpga_arria10_defconfig
> > > > > > b/configs/socfpga_arria10_defconfig
> > > > > > index 6ebda81..8158dbb 100644
> > > > > > --- a/configs/socfpga_arria10_defconfig
> > > > > > +++ b/configs/socfpga_arria10_defconfig
> > > > > > @@ -27,8 +27,16 @@
> > > > > > CONFIG_MTDIDS_DEFAULT="nor0=ff705000.spi.0"
> > > > > >  # CONFIG_EFI_PARTITION is not set
> > > > > >  CONFIG_DEFAULT_DEVICE_TREE="socfpga_arria10_socdk_sdmmc"
> > > > > >  CONFIG_ENV_IS_IN_MMC=y
> > > > > > +CONFIG_SPL_ENV_SUPPORT=y
> > > > > >  CONFIG_SPL_DM=y
> > > > > >  CONFIG_SPL_DM_SEQ_ALIAS=y
> > > > > > +CONFIG_SPL_DM_MMC=y
> > > > > > +CONFIG_SPL_MMC_SUPPORT=y
> > > > > > +CONFIG_SPL_EXT_SUPPORT=y
> > > > > > +CONFIG_SPL_FAT_SUPPORT=y
> > > > > > +CONFIG_SPL_DRIVERS_MISC_SUPPORT=y
> > > > > > +CONFIG_FS_FAT_MAX_CLUSTSIZE=16384
> > > > > This breaks systems with large FAT clusters. Why is this
> > > > > needed
> > > > > for
> > > > > programming the FPGA from MMC ?
> > > > This is final tuning in term of getting balance between
> > > > performance
> > > > and
> > > > SPL image size for the socdk devkit. User can change that if
> > > > they
> > > > need
> > > > large FAT cluster in their design, right?
> > > I think it'd rather make sense to fix the FAT driver to avoid
> > > statically
> > > allocating those massive buffers for big clusters. I think that
> > > can
> > > be
> > > done by allocating those on stack instead ... or mallocating
> > > them.
> > I need to explore 1st as i'm not familiar with FAT driver. Or can
> > we
> > temporary keeping this patch 1st until FAT issue is separately
> > fixed?
> Please explore this, it'll be beneficial in the long run.
There is a progress on working to move statically allocating into
dynamically allocation https://www.mail-archive.com/u-boot at lists.denx.d
e/msg308353.html . 

I quickly apply the patch and having minor fixing on it. This indeed
reduce the SPL image size, but creating overflow/corruption during
runtime. So, the problem is still not enough memory for the SPL.

I think we can add a new SPL_FAT_WRITE config to exclude the
fat_write.c from SPL, because most of the time, SPL needs very simple
FAT reading. This would help us save 64KB memory space if that's
default value for FAT cluster.

What do you think?
>