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Visitor
Visitor
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Registered: ‎10-26-2017

How to disable UART for Serial

Hello Guys,

 

Currently i am using Zynq-7000 Soc having two UART named UART0 and UART1 , UART0 is used for Serial log on my SOC board, due to some requirment i wanted to disable UART0 for serial, i mean to say there is no serial for UART log.

 

so my queation is where i need to disable UART0 for serial, i have already try to disable uart0 info in 

 

aliases {

           /* serial0 = &uart0;*/ /* commented to disable serial*/

           spi0 = &qspi;

     };

     chosen {

           /*bootargs = "console=ttyPS0,115200 earlyprintk root=mtd:jffs2 rw rootfstype=jffs2"; */ /* modified this line and written below , to avoid serial init */

           bootargs = "earlyprintk root=mtd:jffs2 rw rootfstype=jffs2";

 

     }; 

system-conf.dtsi file bu not succeds.

 

can anyone suggest me where i needs to change in the kernel  apart from dtsi file ?

 

 

Regards,

prakash kumar  

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Moderator
Moderator
879 Views
Registered: ‎07-31-2012

Re: How to disable UART for Serial

Hi @prakash_k

 

Can you try this at your end to remove uart0 entry in aliases of system-conf.dtsi file?

 

aliases { 
serial0 = &ps7_uart_0; /* Remove this if you do not want console to opt or choose uart1/
ethernet0 = &gem0;
spi0 = &qspi;
};

 

&ps7_uart_0 {

 status = "disbaled";

}

 

Regards

Praveen


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Visitor
Visitor
853 Views
Registered: ‎10-26-2017

Re: How to disable UART for Serial

Hi Praveen,

 

i have tried your suggestion but my system is not booting, since UART log is not coming after making UART0 disable i am not able to find where its goes wrong.

I have attached the device tree file for your refrence, please see my device tree file and give suggest me what are tghings required to be removed .

please keep in my i am going to use UART0 for some other purposes, so if we disable the Status of UART0 then i may not able to use for other purposes.

 

 

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Moderator
Moderator
830 Views
Registered: ‎07-31-2012

Re: How to disable UART for Serial

Hi @prakash_k,

 

Disabling the UART steps are correct. 

Yes, if you do not enable serial port it is true wont be able to to see boot log at all which will not help you to know if system is up or not. Verified your files and looks like these are original file where you havent edited anything.

 

What is the exact requirement? Are you looking for solution for not use UART port at all and expect to boot from SD /QSPI?

 

Please check if this AR where disabling the earlyprintk helps you and choose appropriate low level debug port

https://www.xilinx.com/support/answers/61039.html 

 

Regards

Praveen


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Moderator
Moderator
821 Views
Registered: ‎07-31-2012

Re: How to disable UART for Serial

Hi @prakash_k,

 

You should have at least a serial port/UART dedicated for kernel boot logs otherwise is will hang as you are seeing when removed UART from dt.

 

Regards

Praveen


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