[PATCH v2 2/9] doc: board/qualcomm: Update RDP build instructions

[Michael Srba]

Hi,

On 4/30/26 11:51, Varadarajan Narayanan wrote:
> On Mon, Apr 20, 2026 at 06:55:25PM +0530, Sumit Garg wrote:
>> Adding Michael
>>
>> On Fri, Apr 10, 2026 at 02:41:47PM +0530, Varadarajan Narayanan wrote:
>>> Add details about the SPL & U-Boot proper build steps, converting to
>>> flashable images, source URLs for the needed binaries and scripts.
>>>
>>> Signed-off-by: Varadarajan Narayanan <varadarajan.narayanan at oss.qualcomm.com>
>>> ---
>>>   doc/board/qualcomm/rdp.rst | 69 ++++++++++++++++++++++++++++++++++++++
>>>   1 file changed, 69 insertions(+)
>>>
>>> diff --git a/doc/board/qualcomm/rdp.rst b/doc/board/qualcomm/rdp.rst
>>> index 99cf8eba57c..d09dba52044 100644
>>> --- a/doc/board/qualcomm/rdp.rst
>>> +++ b/doc/board/qualcomm/rdp.rst
>>> @@ -42,6 +42,67 @@ on your device with::
>>>
>>>   U-Boot should be running after a reboot (``reset``).
>>>
>>> +Build steps for IPQ5210 based Qualcomm Dragonwing F8 & N8 Platforms:
>>> +====================================================================
>> Rather than just the build steps, please describe the overall boot flow.
>> And since you have created a common SPL file for all the Qcom platforms,
>> can you ellaborate on how the boot flow is going to be reused across
>> Qcom platforms. Maybe we just need a dedicated spl.rst document here.
> Ok.
>
>> Also, how does this series align with one for SPL support on SDM845 here
>> [1]? Are there things that both SPL ports can reuse from each other?
>>
>> [1] https://lore.kernel.org/all/20260411-qcom_spl-v2-0-9609557cf562@seznam.cz/
> As I understand, board_spl.c and spl.c (in arch/arm/mach-snapdragon) of
> Michael's patch and mine can reuse spl_boot_device() to include
> BOOT_DEVICE_DFU and reset_cpu().
>
> However, I still have to figure under which conditions spl_boot_device()
> can return BOOT_DEVICE_DFU.
I'm 99% sure there is a register somewhere that can be read to determine
if the device booted via EDL. I think that's exactly when we would
want to load u-boot proper over usb, other than that it could possibly
also be used as a fallback if booting from ufs/emmc fails.
>
> Thanks
> -Varada
>
> [ . . . ]