On Wed, Nov 14, 2012 at 10:19 AM, Stefano Babic <sba...@denx.de> wrote:
> On 14/11/2012 11:29, Otavio Salvador wrote: > > > > Hi Otavio, > > > > > In the text you have the offset to save the image onto a NAND offset so > > I fail to see how it'd be used for SD-Card. > > > > Can you elaborate it a bit? > > No, I can't without introducing errors. Current code supports Falcon > only booting from NAND - I do not think that it is a big thing to use > another media, but it is not yet done. This document must So I'd say to drop the SD-Card from the document. > > +and can be generalized seen as a way to start an image performing > > the minimum > > +required initialization. SPL initializes mainly the RAM controller, > > and after > > +that copies U-Boot image into the memory. The "Falcon" mode extends > > this way > > +allowing to start the Linux kernel directly from SPL. A new command > > is added > > +to U-Boot to prepare the parameters that SPL must pass to the > > kernel, using > > +ATAGS or Device Tree. > > + > > +Falcon adds a command under U-Boot to reuse all code responsible to > > prepare > > +the interface with the kernel. In usual U-boot systems, these > > parameters are > > +generated each time before loading the kernel, passing to Linux the > > address > > +in memory where the parameters can be read. > > +With falcon, this snapshot can be saved into persistent storage and > > SPL is > > +informed to load it before running the kernel. > > > > > > You mix Falcon and falcon. > > You're right, there are already comments about this. This will be fixed > globally in V3 (I will use Falcon Mode consistently). > > > I'd say you always use Falcon as it is the > > name of the feature so it ought to be in upper case. Another thing, > > 'With falcon, ' ought to be move to the previous line or have an empty > > line before it. > > Ok > > > > > > > +To boot the kernel, these steps under a Falcon-aware U-Boot are > > required: > > + > > +1. Boot the board into U-Boot. > > +Use the "spl export" command to generate the kernel parameters area > > or the DT. > > +U-boot runs as when it boots the kernel, but stops before passing > > the control > > +to the kernel. > > + > > +2. Saves the prepared snapshot into persistent media. > > +The address where to save it must be configured into board > > configuration > > +file (CONFIG_CMD_SPL_NAND_OFS for NAND). > > > > > > And for others? > > Not yet implemented, patches welcome ! But you are right, there is > already a patch to use a NOR flash that should flow soon into mainline. > I will check and add documentation for it. For the orher media, the > document must be updated together when they will be full supported. > > > > > > > > +3. Boot the board into "Falcon" mode. SPL will load the kernel and > copy > > +the parameters area to the required address. > > + > > +It is required to implement a custom mechanism to select if SPL > > loads U-Boot > > +or another image. > > +The value of a GPIO is a simple way to operate the selection, as > > well as > > +reading a character from the SPL console if CONFIG_SPL_CONSOLE is > set. > > > > > > An empty line before "The value"? > > Ok > > Best regards, > Stefano Babic > > -- > ===================================================================== > DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany > Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sba...@denx.de > ===================================================================== > -- Otavio Salvador O.S. Systems E-mail: ota...@ossystems.com.br http://www.ossystems.com.br Mobile: +55 53 9981-7854 http://projetos.ossystems.com.br
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