[PATCH] configs: Add pixel3_defconfig for Pixel 3 / 3 XL

[David Heidelberg]

Hello Casey.

On 29/07/2025 13:52, Casey Connolly wrote:
> Hi David,
> 
> Thanks for the patch! Great to see more devices up and running :D
> 
> On 7/29/25 12:39, David Heidelberg wrote:
>> Introduce a defconfig for the Pixel 3 and Pixel 3 XL.
>>
>> On these devices, U-Boot must be chainloaded via Fastboot. However, 
>> due to
>> a Fastboot bug, U-Boot won’t start unless a specific condition is met.
>>
>> To work around this, U-Boot must provide a TEXT_OFFSET of 0x00080000,
>> which allows Fastboot to successfully launch U-Boot.
> 
> tbh I think we could just make this the default TEXT_BASE, since we 
> don't set one in qcom_defconfig. I don't think(?) that would mess up 
> anything else since U-Boot is relocatable anyways.
> 
> Neil: any thoughts there?
> 
>>
>> Clearing the framebuffer improves the Pixel 3 experience,
>> as it prevents collisions with the Fastboot logo left on the display.
> 
> Does framebuffer actually work on the 3 (non-XL)? This reminds me that 
> we should turn off dcache flush for simplefb heh

I can't confirm for Pixel 3 (at least until I meet with Petr Hodina and 
test), but generally after defining the FB node in dts, it *should*.

> 
>>
>> Instead of:
>> $ make CROSS_COMPILE=aarch64-linux-gnu- O=.output qcom_defconfig qcom- 
>> phone.config
>> do
>> $ make CROSS_COMPILE=aarch64-linux-gnu- O=.output pixel3_defconfig 
>> qcom-phone.config
>>
>> Cc: Neil Armstrong <neil.armstrong at linaro.org>
>> Cc: Casey Connolly <casey.connolly at linaro.org>
>> Signed-off-by: David Heidelberg <david at ixit.cz>
>> ---
>>   configs/pixel3_defconfig | 13 +++++++++++++
>>   1 file changed, 13 insertions(+)
>>   create mode 100644 configs/pixel3_defconfig
> 
> I think this makes more sense as a config fragment than a standalone 
> defconfig, since it's just changing a few core options that don't have 
> any other effects
> 
> $ make qcom_defconfig google-blueline.config qcom-phone.config
> 
> What do you think? Otherwise it should be renamed to 
> qcom_google_blueline_defconfig or something like that.

I have nothing against config fragment, but the blueline and crosshatch 
are HW wise almost identical differentiating in peripherals, so this 
configuration should be common for both of them.

> 
>>
>> diff --git a/configs/pixel3_defconfig b/configs/pixel3_defconfig
>> new file mode 100644
>> index 00000000000..9c0c8ca63c4
>> --- /dev/null
>> +++ b/configs/pixel3_defconfig
>> @@ -0,0 +1,13 @@
>> +# Pixel 3 has special requirement to have TEXT_BASE set for the 
>> fastboot.
>> +
>> +#include "qcom_defconfig"
>> +
>> +# Otherwise buildman thinks this isn't an ARM platform
>> +CONFIG_ARM=y
>> +
>> +# some Pixel 3 bootloaders aren't able to start without TEXT_BASE
>> +CONFIG_TEXT_BASE=0x80080000
>> +CONFIG_HAVE_SYS_UBOOT_START=y
> 
> Can you explain the purpose of HAVE_SYS_UBOOT_START here? It just allows 
> for SYS_UBOOT_START which afaict isn't used?

I re-did the testing and this option is not needed, so I'm happy to drop 
it in next revision.

> 
>> +
>> +# fastboot logo distorts u-boot output
>> +# CONFIG_NO_FB_CLEAR is not set
> 
> I'd like to add this to qcom_defconfig, I was holding off until I could 
> add an option to prevent simplefb from doing dcache flash on qcom which 
> makes display refreshes actually fast... Would you be interested in 
> adding a config option for that?

If you can insert this option into the qcom_defconfig, that would likely 
make sense.


Thank you for the review,
David

> 
> Kind regards,// Casey (she/her)

-- 
David Heidelberg