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

[Prabhakar Lad <prabhakar.lad@ti.com>]

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@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@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@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.
2: The revision number differs for both.

Thx,
--Prabhakar

> Regards, Christian
>