[U-Boot] [PATCH 1/2 V2] arm926: Flush the data cache before disabling it.

[Sughosh Ganu]

hi Christian,

On Thu Jan 12, 2012 at 03:04:37PM +0100, Christian Riesch wrote:
> On Thu, Jan 12, 2012 at 2:53 PM, Sughosh Ganu <urwithsughosh at gmail.com> wrote:
> > On Thu Jan 12, 2012 at 01:03:05PM +0100, Christian Riesch wrote:

<snip>

> >>
> >> Since all my tests were successful I wonder what issues did you have
> >> with the cache? Can you describe the problems you had? I think the
> >> difference is that you are booting from NAND and have an OMAP-L138,
> >> whereas I boot from SPI (on the da850evm) or from NOR (on calimain)
> >> and have an AM1808 on both boards, right?
> >
> >  Thanks a lot for all the testing. One difference i think we have on
> >  these boards and hawkboard, is that on hawkboard, the rbl configures
> >  the memory and loads the target image(spl in this case) directly to
> >  the ram. Looking at da850evm's lds file, it looks like the spl
> >  gets loaded to the sram, configures dram and then copies u-boot to
> >  the target load address.
> 
> This is only true if the SPL is actually used. Have a closer look at
> my test report, I tested three different methods:
> 
> 1) The first test was done with the SPL and yes, here the RBL loads
> the SPL into SRAM, initializes DDR memory and then copies u-boot.bin
> to DDR memory.
> 2) The second test was done with TI's UBL. Here, the RBL loads the UBL
> into SRAM, the UBL initializes DDR memory and then copies u-boot.bin
> to DDR memory.
> 3) The third test was done without SPL and without UBL: Here the DDR
> memory init is in the AIS, so in fact the RBL does memory
> initialization and then RBL loads u-boot.bin to DDR memory. This is
> the same case that you have on the hawkboard (only that you have the
> OMAP-L138 and NAND flash instead) and it works for me regardless of
> your patch.

  Yes, the third case is similar to the one used in hawkboard. I'm not
  sure as to why it causes a problem on my board, though i'm not sure
  if we can compare the two cases, as we have different rbl's. It
  could be that the rbl used on hawkboard initialises the caches, as
  the caches are off by default on reset.

  Here are the values i use in my ini file for ddr init.

[EMIF3DDR]
PLL1CFG0 = 0x15010001
PLL1CFG1 = 0x00000002

DDRPHYC1R = 0x00000043
SDCR = 0x00134632
SDTIMR = 0x26492a09
SDTIMR2 = 0x7d13c722
SDRCR = 0x00000249
CLK2XSRC = 0x00000000

-sughosh