[U-Boot] [PATCH 1/7] spl: pbl: Add new SPL image for pblimage tool

[York Sun <yorksun@freescale.com>]

On 09/21/2014 11:17 PM, Wang Huan-B18965 wrote:
> 
> [Alison Wang] Let me explain the sequence.
> 
> 1. u-boot-spl.bin is produced. The size of it is not a fixed value.
> 
> 2. u-boot-spl-pbl-pad.bin is produced. The size of it is defined by
> CONFIG_SPL_MAX_SIZE. For detail, u-boot-spl-pbl-pad.bin is generated
> by padding u-boot-spl.bin to the size of CONFIG_SPL_MAX_SIZE.
> 
> The following is the reason for using u-boot-spl-pbl-pad.bin.
> 
> First of all, the SPL part need to be reorganized for the recognition
> of PBL through the pblimage tool.
> 
> For the pblimage tool, the SPL image is splitted into 64 byte chunks,
> and PBL needs a command for each piece. In current pblimage tool,
> the size of the SPL image(u-boot-spl.bin) should be a fixed value
> like PowerPC. Well, for LS102xA and some other ARM platforms, the size
> of the SPL image (u-boot-spl.bin) is changeable. So a new image
> spl/u-boot-spl-pbl-pad.bin is produced, and the size of it is a fixed
> value "CONFIG_SPL_MAX_SIZE". Then use u-boot-spl-pbl-pad.bin instead
> of spl/u-boot-spl.bin to generate spl/u-boot-spl.pbl.
> 
> 3. spl/u-boot-spl.pbl is produced through pblimage tool. As
> CONFIG_SPL_PBL_PAD is enabled, spl/u-boot-spl-pbl-pad.bin is used as
> the source file instead of spl/u-boot-spl.bin.
> 
> 4. u-boot-with-spl-pbl.bin is produced. For detail, u-boot-with-spl-pbl.bin
> is generated by padding spl/u-boot-spl.pbl to the offset of CONFIG_SPL_PAD_TO
> and adding u-boot.img.
> 
> As the size of spl/u-boot-spl.pbl is not a fixed value, we pad it to
> the offset of CONFIG_SPL_PAD_TO. So it is convenient for us to determine
> the location of u-boot.img in SD card.
> 

Sorry for the late respond. I was away for an urgent project.

If I understand you correctly, you define a CONFIG_SPL_MAX_SIZE and pad the
final binary file to this size. How do you determine the size? I understand PBL
loading mechanism. Would it be possible to pad to 64 byte boundary (or any
practical size since it is adjustable) and avoid the definition of
CONFIG_SPL_MAX_SIZE?

York