[PATCH v4 08/10] rockchip: binman: Use the skip-at-start prop in simple-bin image

[Quentin Schulz]

Hi Simon,

On 4/9/25 3:33 PM, Simon Glass wrote:
> Hi Quentin,
> 
> On Wed, 9 Apr 2025 at 07:32, Quentin Schulz <quentin.schulz at cherry.de> wrote:
>>
>> Hi Simon,
>>
>> On 4/9/25 3:22 PM, Simon Glass wrote:
>>> Hi Quentin,
>>>
>>> On Wed, 9 Apr 2025 at 04:57, Quentin Schulz <quentin.schulz at cherry.de> wrote:
>>>>
>>>> Hi Jonas, Simon,
>>>>
>>>> On 3/29/25 4:06 PM, Jonas Karlman wrote:
>>>>> From: Simon Glass <sjg at chromium.org>
>>>>>
>>>>> The simple-bin image is normally written to MMC media at block 64, which
>>>>> is a 32K offset from start of storage media.
>>>>>
>>>>> Set the skip-at-start property to 0x8000 (32 KiB) so that fdtmap and
>>>>> other embedded binman symbols in the output binary is referencing image
>>>>> offsets correctly.
>>>>>
>>>>
>>>> Shouldn't we have this commit BEFORE we add the `fdtmap` node since we
>>>> know it's wrong before this commit?
>>>>
>>>>> Signed-off-by: Simon Glass <sjg at chromium.org>
>>>>> Signed-off-by: Jonas Karlman <jonas at kwiboo.se>
>>>>> ---
>>>>> Changes in v4:
>>>>> - Drop defconfig changes
>>>>> - Split from "VBE serial part H: Implement VBE on Rockchip RK3399"
>>>>>
>>>>> Changes in v2:
>>>>> - Move this patch to the end of the series
>>>>> - Drop 0x8000 offset for SPI
>>>>> ---
>>>>>     arch/arm/dts/rockchip-u-boot.dtsi | 3 ++-
>>>>>     1 file changed, 2 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/arch/arm/dts/rockchip-u-boot.dtsi b/arch/arm/dts/rockchip-u-boot.dtsi
>>>>> index fb38b7b80c43..65b81bf58626 100644
>>>>> --- a/arch/arm/dts/rockchip-u-boot.dtsi
>>>>> +++ b/arch/arm/dts/rockchip-u-boot.dtsi
>>>>> @@ -154,6 +154,7 @@
>>>>>         simple-bin {
>>>>>                 filename = "u-boot-rockchip.bin";
>>>>>                 pad-byte = <0xff>;
>>>>> +             skip-at-start = <0x8000>;
>>>>>
>>>>>                 mkimage {
>>>>>                         filename = "idbloader.img";
>>>>> @@ -178,7 +179,7 @@
>>>>>     #else
>>>>>                 u-boot-img {
>>>>>     #endif
>>>>> -                     offset = <CONFIG_SPL_PAD_TO>;
>>>>> +                     offset = <(CONFIG_SPL_PAD_TO + 0x8000)>;
>>>>
>>>> This is confusing. The documentation states:
>>>>
>>>> """
>>>> offset:
>>>>        This sets the offset of an entry within the image or section containing
>>>>        it.
>>>> """
>>>>
>>>> My understanding is that it should be relative to the beginning of the
>>>> image but this now needs the knowledge of where it will be stored on the
>>>> MMC device (via the value in skip-at-start).
>>>>
>>>> Why is skip-at-start automatically deducted from offset?
>>>
>>> This is how binman works[1]. We are trying to use the feature designs
>>
>> Why is it deducted?
> 
> Are you asking why skip-at-start is deducted from the offset?
> 

Yes

> Regards,
> Simon