[U-Boot] [PATCH v2 16/18] da850_am18xxevm: Add README.da850_am18xxevm

[Tom Rini]

On Wed, Aug 22, 2012 at 03:35:30PM +0530, Prabhakar Lad wrote:
> Hi Christian,
> 
> On Wednesday 22 August 2012 02:47 PM, Christian Riesch wrote:
> > Hi Prabhakar,
> > 
> > On Wed, Aug 22, 2012 at 11:07 AM, Prabhakar Lad <prabhakar.lad at ti.com> wrote:
> >> Hi,
> >>
> >> On Wednesday 22 August 2012 01:43 PM, Christian Riesch wrote:
> >>> [cc'd Manjunath Hadli]
> >>>
> >>> Hi Tom,
> >>>
> >>> On Mon, Aug 20, 2012 at 6:45 PM, Tom Rini <trini at ti.com> wrote:
> >>>> Add a board-specific README that documents how to write u-boot.ais to
> >>>> the SPI found on this board.
> >>>>
> >>>> Changes-series: 2
> >>>> - Add
> >>>>
> >>>> Signed-off-by: Tom Rini <trini at ti.com>
> >>>> ---
> >>>>
> >>>>  board/davinci/da8xxevm/README.da850_am18xxevm |   53 +++++++++++++++++++++++++
> >>>>  1 file changed, 53 insertions(+)
> >>>>  create mode 100644 board/davinci/da8xxevm/README.da850_am18xxevm
> >>>>
> >>>> diff --git a/board/davinci/da8xxevm/README.da850_am18xxevm b/board/davinci/da8xxevm/README.da850_am18xxevm
> >>>> new file mode 100644
> >>>> index 0000000..382b718
> >>>> --- /dev/null
> >>>> +++ b/board/davinci/da8xxevm/README.da850_am18xxevm
> >>>> @@ -0,0 +1,53 @@
> >>>> +Summary
> >>>> +=======
> >>>> +The README is for the boot procedure used for the LogicPD AM1808 EVM.
> >>>> +
> >>>> +The board is booted in three stages. The initial bootloader which executes
> >>>> +upon reset is the Rom Boot Loader(RBL) which sits in the internal ROM. The
> >>>> +RBL initialises the memory and the SPI controller and reads the AIS image
> >>>> +starting at block 0.  This image can contain both the SPL and U-Boot
> >>>> +binaries.
> >>>> +
> >>>> +AIS is an image format defined by TI for the images that are to be
> >>>> +loaded to memory by the RBL. The image is divided into a series of
> >>>> +sections and the image's entry point is specified. Each section comes
> >>>> +with meta data like the target address the section is to be copied to
> >>>> +and the size of the section, which is used by the RBL to load the
> >>>> +image. At the end of the image the RBL jumps to the image entry
> >>>> +point.
> >>>> +
> >>>> +The secondary stage bootloader(spl) which is loaded by the RBL then loads
> >>>> +the u-boot from a predefined location in SPI to DDR and jumps to the u-boot
> >>>> +entry point.
> >>>> +
> >>>> +
> >>>> +Compilation
> >>>> +===========
> >>>> +To build a SPI-bootable image, run 'make da850_am18xxevm'.  This will build
> >>>
> >>> da850_am18xxevm is for the Spectrum Digital EVM for the AM1808. For
> >>> the Logic PD board you will need 'make da850evm'. See [1]
> >>>
> >>   May be having a common README for am18x and omap-l138 would be good ?
> >>
> > 
> > This is a good idea.
> > 
> > But just to make it clear: Afaik the da850evm configuration works for
> > both the AM1808 and the OMAP-L138 board from LogicPD (at least I am
> > using it with the AM1808 experimenter's kit from LogicPD). The
> > da850_am18xxevm is for the Spectrum Digital board. At least this is
> > what I understood from the discussion with Manjunath Hadli in the in
> > the u-boot mailing list thread I cited earlier. I hope this is
> > correct, I haven't got other boards than the AM1808 board from LogicPD
> > to test.
> > 
> AFAIK the difference between AM1808 and OMAP-L138 is that,
> 1: The AM1808 has EEPROM and stores the MAC address in it where as
> OMAP-L138 stores the MAC address in SPI flash.

I don't think this is right.  I believe on the Logic PD board it's
stored in SPI (I know mine isn't stored in EEPROM).  I think the answer
is that the OMAP-L138 has DSP and the AM part does not.  This would mean
that Logic PD gets the most re-use out of the base-board possible :)

-- 
Tom