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

[Huan Wang]

Hi, York,

> 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?

[Alison Wang] I checked the size of spl/u-boot-spl.bin, then determined
CONFIG_SPL_MAX_SIZE which is larger than the size of spl/u-boot-spl.bin.
For Pblimage tool, the size of SPL image need to be a fixed value.
For example, for PowerPC, no matter how the SPL code is changed, the
size of spl/u-boot-spl.bin is always 0x28000 (so the "pbl_cmd_initaddr"
is always 0x82000000). But for LS1, the size of spl/u-boot-spl.bin is not
a fixed size. When the SPL code is changed, the size of spl/u-boot-spl.bin
is changed, so "pbl_cmd_initaddr" is changed too. It's unacceptable for pblimage
tool("pbl_cmd_initaddr" need to be a fixed value). To fix this issue, I use
CONFIG_SPL_MAX_SIZE.

Do you mean there is some approach to pad spl/u-boot-spl.bin to any
practical size and avoid the definition of CONFIG_SPL_MAX_SIZE?


Best Regards,
Alison Wang