How to disable Peripherals in stm32mp1 u boot source?

Sindhu Vadde · ‎2022-01-24

Hi,

We are using stm32mp157a processor in my custom board.In my custom board we have limited peripherals so i need to disable remaining peripherals like ltdc and hdmi ,etc. I disabled in dts files but it didn't effected. How can i disable peripherals in u boot?

Kevin HUBER · ‎2022-02-01

Hi @[Sindhu Vadde] ,

If you only disable the peripherals, the size will remain the same. When you disable a peripheral, it will not be probed during the boot, but the code of the driver is still built and present in the final image.

If you want to completely remove the code of a specific driver from your U-Boot, you have to disable the CONFIG that enable the build of the driver. You must run:

make menuconfig

Please have a look at the wiki: https://wiki.st.com/stm32mpu/wiki/Menuconfig_or_how_to_configure_kernel

And you disable the drivers that you do not need.

But regarding your first request about "ltdc and hdmi", I don't understand because normally the driver related to HDMI is already disabled on U-Boot.

The configuration that enables the hdmi video driver is VIDEO_SUNXI, which is disabled by default:

And the configuration which allows to choose to use the HDMI is CONFIG_LCD_MODE :

But it is also disabled by default

Maybe you are talking about the support of the DSI peripheral, in this case you can disable it by disabling DM_VIDEO :

If this configuration is disable, the compelte driver model to support video will be disabled, even the splash screen of u-boot will be turned off.

Regards,

Kevin

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Olivier GALLIEN · ‎2022-01-25

Hi @Sindhu Vadde ,

What do you mean by "it didn't effected" ?

How do you notice they are not disabled after dts update ?

Olivier

Olivier GALLIEN
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Sindhu Vadde · ‎2022-01-26

Hi,

The uboot image size is not reduced before disabling pheperials i observed image size and afer disabling it shoud reduced right? but after disbaling also i got same image size.

Kevin HUBER · ‎2022-02-01

Hi @[Sindhu Vadde] ,

If you only disable the peripherals, the size will remain the same. When you disable a peripheral, it will not be probed during the boot, but the code of the driver is still built and present in the final image.

If you want to completely remove the code of a specific driver from your U-Boot, you have to disable the CONFIG that enable the build of the driver. You must run:

make menuconfig

Please have a look at the wiki: https://wiki.st.com/stm32mpu/wiki/Menuconfig_or_how_to_configure_kernel

And you disable the drivers that you do not need.

But regarding your first request about "ltdc and hdmi", I don't understand because normally the driver related to HDMI is already disabled on U-Boot.

The configuration that enables the hdmi video driver is VIDEO_SUNXI, which is disabled by default:

And the configuration which allows to choose to use the HDMI is CONFIG_LCD_MODE :

But it is also disabled by default

Maybe you are talking about the support of the DSI peripheral, in this case you can disable it by disabling DM_VIDEO :

If this configuration is disable, the compelte driver model to support video will be disabled, even the splash screen of u-boot will be turned off.

Regards,

Kevin

In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.

Kevin HUBER · ‎2022-02-09

Hi @Sindhu Vadde ,

In order to give better visibility on the answered topics, please click on 'Select as Best' on the reply which solved your issue or answered your question. See also 'Best Answers'

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