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

[Christian Riesch]

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.

Regards, Christian