[PATCH v2] spl: fit: List DTOs applied by SPL in U-Boot control DT

[Marek Vasut]

On 6/28/24 9:32 AM, Simon Glass wrote:
> Hi Marek,

Hi,

>> ---
>>   common/spl/spl_fit.c                | 29 +++++++++++++++++++++++++++--
>>   doc/device-tree-bindings/config.txt | 11 +++++++++++
>>   2 files changed, 38 insertions(+), 2 deletions(-)
> 
> Once this is figured out, can you extend test/image/spl_load_os.c to
> test this code?

It seems there is nothing which would do even basic tests for SPL 
fitImage DT handling in that test? Or am I reading the current test wrong ?

>> diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c
>> index 988125be008..0a6b5ea8212 100644
>> --- a/common/spl/spl_fit.c
>> +++ b/common/spl/spl_fit.c
>> @@ -363,6 +363,7 @@ static int spl_fit_append_fdt(struct spl_image_info *spl_image,
>>   {
>>          struct spl_image_info image_info;
>>          int node, ret = 0, index = 0;
>> +       char dtoname[256];
>>
>>          /*
>>           * Use the address following the image as target address for the
>> @@ -448,9 +449,13 @@ static int spl_fit_append_fdt(struct spl_image_info *spl_image,
>>                          if (ret < 0)
>>                                  break;
>>
>> -                       /* Make room in FDT for changes from the overlay */
>> +                       /*
>> +                        * Make room in FDT for changes from the overlay,
>> +                        * the overlay name and the trailing NUL byte in
>> +                        * that name.
>> +                        */
>>                          ret = fdt_increase_size(spl_image->fdt_addr,
>> -                                               image_info.size);
>> +                                               image_info.size + strlen(str) + 1);
> 
> Oh and I missed the room for the property, sorry. It needs something like this:
> 
> ALIGN(strlen(str) + 1, 4) + 12 + 4
> 
> the first bit is the string-table size increase
> 
> 12 is sizeof(struct fdt_property)
> 4 is the u32 size
> 
> Alos, is there any way to check that there is actually enough space to
> increase the size?

fdt_increase_size() would fail if there isn't enough space, so that 
should cover the check.

>> diff --git a/doc/device-tree-bindings/config.txt b/doc/device-tree-bindings/config.txt
>> index f50c68bbdc3..7aa6d9a72c6 100644
>> --- a/doc/device-tree-bindings/config.txt
>> +++ b/doc/device-tree-bindings/config.txt
>> @@ -95,6 +95,17 @@ rootdisk-offset (int)
>>   silent-console (int)
>>          If present and non-zero, the console is silenced by default on boot.
>>
>> +u-boot,spl-applied-dto-* (int)
>> +       Emitted by SPL into U-Boot control DT root node in case a DTO from
>> +       fitImage was applied on top of U-Boot control DT by the SPL fitImage
>> +       loader. The single integer cell indicates in which order was the DTO
>> +       applied by the SPL and matches the index of the DTO in the fitImage.
>> +       DTOs in fitImage may be skipped using board_spl_fit_append_fdt_skip(),
>> +       therefore the integers might not be monotonically incrementing, there
>> +       may be gaps. This property can be used to determine which DTOs were
>> +       applied by the SPL from running U-Boot by inspecting the U-Boot
>> +       control DT.
> 
> Should we send a binding with this? I wonder if it would be better to
> make the filename a property value rather than including it in the
> property name/string table? That way you would not need the
> integers...the ordering would be enough.
> 
> E.g.
> 
> u-boot,spl-applied-dtos = "fdt-dto-imx8mp-dhcom-som-overlay-eth2xfast",
>        "fdt-dto-imx8mp-dhcom-pdk-overlay-eth2xfast";
> 
> But that might be more annoying to construct as you would probably
> need fdt_setprop_placeholder()

It is easier to test for a presence of property from U-Boot shell, also 
the property is integer where the integer indicates the index of the DTO 
when it was applied.