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

[Tom Rini]

On 08/20/2012 10:09 PM, Prabhakar Lad wrote:
> Hi Tom,
> 
> Thanks for the patch.
> 
> On Monday 20 August 2012 10:15 PM, Tom Rini 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
>> +the u-boot.ais file that needs to be written to SPI flash.
>> +
>> +
>> +Flashing the images to Nand
>> +===========================
>> +The AIS image can be written to SPI flash using the following commands.
>> +Assuming that the network is configured and enabled and the u-boot.ais file
>> +is tftp'able.
>> +
>> +U-Boot > sf probe 0
>> +U-Boot > sf erase 0 +320000
>> +U-Boot > tftp u-boot.ais
>> +U-Boot > sf write c0700000 0 $filesize
>> +
>   Is this procedure to be done in Nand boot mode ?

This board, as far as I know (which isn't much) doesn't use NAND, just
SPI.  The USE_NAND section of da850evm.h doesn't seem reachable today at
least.

-- 
Tom