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Adventurer
Adventurer
419 Views
Registered: ‎07-11-2018

ZC702 booting stops without UART

Hi

 

I'm using ZC702 platform with petalinux 2018.1, when UART (USB to uart) not connected the booting halts/stuck at u-boot prompt. After connecting UART it is verified the booting stuck at u-boot prompt. After issuing 'boot' command it successfully boots linux. When UART is connected there is no issue in loading linux, the entire boot succeeds. 

 

Any pointers to fix this issue, moreover petalinux 2018.1 doesn't clone u-boot.

 

Please suggest.

 

Thanks

Umamahesh

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5 Replies
Xilinx Employee
Xilinx Employee
376 Views
Registered: ‎06-27-2017

Re: ZC702 booting stops without UART

Hi @umamahesh,

 

I am confused with your use case.

May I know are you getting any error message in u-boot console? can you share the all u-boot environment varilables?

 

Regards,

kranthi

 

Best Regards
Kranthi
--------------------------
Don't forget to reply, kudo, and accept as solution.
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Adventurer
Adventurer
370 Views
Registered: ‎07-11-2018

Re: ZC702 booting stops without UART

Hi Kranthi,

 

There is no error. In my customised board we have separate RS 232 converter added and separately powered, which in turn connects to serial to USB converter to the host PC. When power to RS 232 converter is switch off, there will not be any logs on the console, but the expectation is Linux should be booted but the booting stopped at u-boot prompt when UART is powered and verified on the console. Unable to understand what is causing this issue. Again if I issue 'boot 'command from u-boot it successfully loads Linux. PFA environment variables.

 

 

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Adventurer
Adventurer
355 Views
Registered: ‎06-03-2015

Re: ZC702 booting stops without UART

hi

 

So it is the way UART is connected with separate power setup and excepting it is causing the Issue.

 

In general, u-boot starts decomress its image starting from borad_init_f (which initiates serial initial, baud rate initial, console initial)  & board_init_r  (takes care of again serial console with intilized variabes from board_init_f  , baud rate set for your board, uart address set for your board, here it will check how many uart ports are connected and their proper address and will identify your actual UART console from include/configs/board_zed.h)

If that uart address matches to your physical connected port (u-boot code is Flat memory) then it starts print messaegs on UART console.

This is flow in u-boot code for UART transimission so now identify the your issue. 

 

Thanks & Regards

Satish G

 

 

 

 

G Satish Kumar
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Adventurer
Adventurer
345 Views
Registered: ‎07-11-2018

Re: ZC702 booting stops without UART

Hi Sathish,

 

I am not sure on your suggestion. You want me to modify the u-boot code. I do not see u-boot is cloned when petalinux is build.

Do you have procedure how to build the u-boot external image with petalinux?

 

Please suggest.

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Adventurer
Adventurer
339 Views
Registered: ‎06-03-2015

Re: ZC702 booting stops without UART

Hi Mahesh,

 

I have provided code flow for U-boot and Intilization part of Uart and can believe it is enabled when it is going to customer build because Xilinx QA team throughly test the Serial console and other I/O Devices 

So there is nothing to change U-Boot Code.

I have provided basic code flow for Understanding and more over in U-boot level UART is basic I/O to make it up

 

Basically there are two UART ports, one is serail console and other one is Debug Console ,In production build Serial consloe will definitely up.

I hope I have cleraed your Issue with UART Initilization part

 

Thanks & Regards

Satish G

 

G Satish Kumar
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