Re: [PATCH 2/2] tools: amlimage: Add support for GXBB eMMC header

Hi Jonas,

On Sat, 4 Jan 2025 at 10:59, Jonas Karlman <[email protected]> wrote:
>
> GXBB BL1 only tries to read boot image from sector 0 on eMMC and sector
> 1 on SD-card. GXL and newer read boot image from sector 1 on both eMMC
> and SD-card.
>
> Vendor BL2 have solved the issue with different offsets by considering
> where BL2 was loaded from to adjust the offset where BL3 is read from.
>
> This provide a different solution to create a boot image that can be
> booted from both eMMC and SD-card and where the offset for reading next
> stage loader can be shared for both boot options.
>
> Inject code, that relocate the payload located at 0x1200 offset in TZRAM
> to the expected offset of 0x1000, into the padding area at offset 0x200
> when a normal GXBB boot image is created. A special GXBB eMMC header can
> then be created that have the payload offset point to this relocate
> code, BL1 will jump to this relocate code when booted from eMMC instead
> of the normal payload start. One effect of this is that the payload size
> limit must be reduced by 512 bytes on GXBB.
>
> Example of how to use it:
>   # Create a normal boot image
>   tools/mkimage -T amlimage -n gxbb -d u-boot-spl.bin bl2.bin
>
>   # Create a boot image with a special eMMC header
>   tools/mkimage -T amlimage -n emmc -d bl2.bin bl2-emmc.bin
>
>   # Write normal boot image to sector 1 of eMMC/SD-card
>   dd if=bl2.bin of=/path/to/dev bs=512 seek=1
>
>   # Write eMMC header, 112 bytes, to start of eMMC
>   dd if=bl2-emmc.bin of=/path/to/dev bs=1 count=112
>
> Or with binman using something like:
>   binman {
>         multiple-images;
>
>         u-boot-gxbb-sd {
>                 filename = "u-boot-gxbb-sd.bin";
>                 pad-byte = <0xff>;
>
>                 mkimage {
>                         filename = "bl2.bin";
>                         args = "-n", "gxbb", "-T", "amlimage";
>
>                         u-boot-spl {
>                         };
>                 };
>         };
>
>         u-boot-gxbb-emmc {
>                 filename = "u-boot-gxbb-emmc.bin";
>                 pad-byte = <0xff>;
>
>                 mkimage {
>                         filename = "bl2-emmc.bin";
>                         args = "-n", "emmc", "-T", "amlimage";
>
>                         blob-ext {
>                                 filename = "bl2.bin";
>                         }
>                 };
>         };
>   };
>
> Signed-off-by: Jonas Karlman <[email protected]>
> ---
>  tools/amlimage-gxbb-relocate.c | 79 ++++++++++++++++++++++++++++++++++
>  tools/amlimage.c               | 37 ++++++++++++++++
>  2 files changed, 116 insertions(+)
>  create mode 100644 tools/amlimage-gxbb-relocate.c
>

I sent [1] some years ago and would quite like to enable the odroid-c2
in my lab. Is that an older version of what you are supporting here?

I heard that there are people working on open source tools, but it has
been a few years and I'd be quite OK to just use vendor tools.

For your docs, could you put them in doc/ instead?

[..]

Regards,
Simon

[1] https://patchwork.ozlabs.org/project/uboot/patch/[email protected]/