-----Original Message----- From: EXT Jagan Teki [mailto:jteki@openedev.com] Sent: Thursday, October 22, 2015 2:55 PM To: Krzeminski, Marcin (Nokia - PL/Wroclaw) marcin.krzeminski@nokia.com Cc: u-boot@lists.denx.de Subject: Re: [U-Boot] Reading data from SPI flash before relocation - what is the best way to do this?
On 22 October 2015 at 17:05, Krzeminski, Marcin (Nokia - PL/Wroclaw) marcin.krzeminski@nokia.com wrote:
Hello,
I want to chose the best aproach to achive something like this: There is a u-boot without SPL and it is copied by bootrom to SDRAM. In first phase (while running *_f functions) I need to read some
configuration data from SPI NOR, and it must be done before DDR config.
Why can't you use SPL? any specific reason?
Since we are already in small SDRAM, so assumption was tha SPL is not needed - which was apparently wrong. Strong argument is that dividing u-boot to u-boot and SPL will consume more flash space, complicate flash layout and already complicated boot process.
Just to be clear are going write the data from spi-nor to SRAM because *_f doesn't have DDR access.
Yes.
I have SPI NOR with enabled MTD support on SPI. Problem is that MTD
uses bss wich is not avalaible yet.
My solutions:
Change linker script to divide bss and rel.dyn sections and clean bss bymyself. Disadventage is that it will enlarge my binary, but it migh be acceptable.
Write code that do not use SPI/MTD frameworks to read configurationdata (data will be on raw so MTD is not needed).
For sure - at least at the moment - I wan't to avoid using SPL and config
compiled into binary.
Maybe there is another way that I can achive that?
-- Jagan | openedev.
Regards, Marcin