On 01/05/2022 16:51, Mikhail Zhilkin wrote:
> On 5/1/2022 11:17 AM, Krzysztof Kozlowski wrote:
>
>> On 30/04/2022 20:54, Mikhail Zhilkin wrote:
>>> patternProperties:
>>> "@[0-9a-f]+$":
>>> - $ref: "partition.yaml#"
>>> + allOf:
>>> + - $ref: "partition.yaml#"
>>> + - if:
>>> + properties:
>>> + compatible:
>>> + contains:
>>> + const: sercomm,sc-partitions
>>> + then:
>>> + properties:
>>> + sercomm,scpart-id:
>>> + description: Partition id in Sercomm partition map. Parser
>>> + uses this id to get partition offset and size values from
>>> + dynamic partition map.
>> Partition offset and size values are not derived from scpart-id. I am
>> sorry but after all these questions - it's the third time now - you
>> never answer why do you need this property and what is it used for. From
>> all the examples it could be simply removed and the partition map will
>> be exactly the same.
> scpart-id is necessary to get (using mtd parser) partition offset and
> size from dynamic partition map (NOT from the reg property):
>
> ❯ xxd -e -c 12 -s $((0x800)) -l $((0x78)) mtd1
> 00000800: 00000000 00000000 00100000 ............
> 0000080c: 00000001 00100000 00100000 ............
> 00000818: 00000002 00200000 00100000 ...... .....
> 00000824: 00000003 00300000 00100000 ......0.....
> 00000830: 00000004 00400000 00600000 ......@...`.
> 0000083c: 00000005 00a00000 00600000 ..........`.
> 00000848: 00000006 01000000 02000000 ............
> 00000854: 00000007 03000000 02000000 ............
> 00000860: 00000008 05000000 01400000 ..........@.
> 0000086c: 00000009 06400000 01b80000 ......@.....
> scpart-id offset size
>
> With sercomm,sc-partitions the reg property will be ignored (offset =
> 0x200000, size = 0x100000) and the values will be taken from partition map.
>
> For example we have this is dts:
>
> partition@200000 {
> label = "Factory";
> reg = <0x200000 0x100000>;
> sercomm,scpart-id = <2>;
> read-only;
> };
>
> Dynamic partition map:
>
> scpart-id = 2; offset = 0x00200000; size = 0x00100000
>
> 00000002 00200000 00100000 ...... .....
>
> In this example the offset and size are the same in reg and dynamic
> partition map. If device have bad blocks on NAND the values will be a
> little different. And we have to take partition offsets from partition
> map to avoid boot loops, wrong eeprom location and other bad things.
>
> Is there anything that needs to be explained in more detail?
Thanks a lot, this clarifies the topic. Looks good. Maybe you could put
parts of this into the scpart-id field description?
Best regards,
Krzysztof
