[U-Boot] [PATCH 2/9] spl: fit: add support for post-processing of images

[Andreas Dannenberg <dannenberg@ti.com>]

On Thu, Jun 23, 2016 at 07:57:13AM -0600, Simon Glass wrote:
> Hi Andreas,
> 
> On 20 June 2016 at 21:34, Andreas Dannenberg <dannenberg@ti.com> wrote:
> > From: Daniel Allred <d-allred@ti.com>
> >
> > The next stage boot loader image and the selected FDT can be
> > post-processed by board/platform/device-specific code, which can include
> > modifying the size and altering the starting source address before
> > copying these binary blobs to their final desitination. This might be
> > desired to do things like strip headers or footers attached to the
> > images before they were packeaged into the FIT, or to perform operations
> > such as decryption or authentication.
> >
> > Signed-off-by: Daniel Allred <d-allred@ti.com>
> > Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
> > ---
> >  common/spl/spl_fit.c | 21 ++++++++++++++++-----
> >  include/image.h      | 15 +++++++++++++++
> >  2 files changed, 31 insertions(+), 5 deletions(-)
> >
> > diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c
> > index 9874708..ecbcb97 100644
> > --- a/common/spl/spl_fit.c
> > +++ b/common/spl/spl_fit.c
> > @@ -121,6 +121,10 @@ static int get_aligned_image_size(struct spl_load_info *info, int data_size,
> >         return (data_size + info->bl_len - 1) / info->bl_len;
> >  }
> >
> > +void __weak board_fit_image_post_process(void **p_src, size_t *p_size)
> > +{
> > +}
> 
> Can you make this a Kconfig option instead of a weak function? It's
> hard enough to trace what a particular board is doing...

Hi Simon,
I understand your point and we did look into doing it but could not come
up with a good way (certainly I don't want to clutter this global file
with any TI stuff) but maybe we were over-thinking it :)

So (roughly) how would you like to see this Kconfig option to be
implemented? I'll be happy to change the implementation if given a
little direction.

Thanks,
Andreas


> 
> > +
> >  int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
> >  {
> >         int sectors;
> > @@ -132,7 +136,7 @@ int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
> >         int data_offset, data_size;
> >         int base_offset, align_len = ARCH_DMA_MINALIGN - 1;
> >         int src_sector;
> > -       void *dst;
> > +       void *dst, *src;
> >
> >         /*
> >          * Figure out where the external images start. This is the base for the
> > @@ -206,8 +210,11 @@ int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
> >                 return -EIO;
> >         debug("image: dst=%p, data_offset=%x, size=%x\n", dst, data_offset,
> >               data_size);
> > -       memcpy(dst, dst + get_aligned_image_overhead(info, data_offset),
> > -              data_size);
> > +       src = dst + get_aligned_image_overhead(info, data_offset);
> > +
> > +       board_fit_image_post_process((void **)&src, (size_t *)&data_size);
> > +
> > +       memcpy(dst, src, data_size);
> >
> >         /* Figure out which device tree the board wants to use */
> >         fdt_len = spl_fit_select_fdt(fit, images, &fdt_offset);
> > @@ -236,8 +243,12 @@ int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
> >          */
> >         debug("fdt: dst=%p, data_offset=%x, size=%x\n", dst, fdt_offset,
> >               fdt_len);
> > -       memcpy(load_ptr + data_size,
> > -              dst + get_aligned_image_overhead(info, fdt_offset), fdt_len);
> > +       src = dst + get_aligned_image_overhead(info, fdt_offset);
> > +       dst = load_ptr + data_size;
> > +
> > +       board_fit_image_post_process((void **)&src, (size_t *)&fdt_len);
> > +
> > +       memcpy(dst, src, fdt_len);
> >
> >         return 0;
> >  }
> > diff --git a/include/image.h b/include/image.h
> > index a8f6bd1..9536874 100644
> > --- a/include/image.h
> > +++ b/include/image.h
> > @@ -1172,4 +1172,19 @@ ulong android_image_get_kload(const struct andr_img_hdr *hdr);
> >   */
> >  int board_fit_config_name_match(const char *name);
> >
> > +/**
> > + * board_fit_image_post_process() - Do any post-process on FIT binary data
> > + *
> > + * This is used to do any sort of image manipulation, verification, decryption
> > + * etc. in a platform or board specific way. Obviously, anything done here would
> > + * need to be comprehended in how the images were prepared before being injected
> > + * into the FIT creation (i.e. the binary blobs would have been pre-processed
> > + * before being added to the FIT image).
> > + *
> > + * @image: pointer to the image start pointer
> > + * @size: pointer to the image size
> > + * @return no return value (failure should be handled internally)
> > + */
> > +void board_fit_image_post_process(void **p_image, size_t *p_size);
> > +
> >  #endif /* __IMAGE_H__ */
> > --
> > 2.6.4
> >
> 
> Regards,
> Simon