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Alpine Linux start up

Posted: Tue Aug 04, 2020 1:08 pm
by kasaudio
Hello all, although this guestion is most likely addresed to Pavel Demin :)

When RP with alpine linux distribution by Pavel Demin is started, the LED0 is blinking till the system is loaded and default application is started. That takes approx. 20 seconds.

Is it possible to change the blinking LED0 to some of the DIO pins? I guess that would require to change the "default" fpga image that is loaded at the very start.

Any comments/suggestions?

Again, Pavel thank you for your contribution.

Re: Alpine Linux start up

Posted: Tue Aug 04, 2020 1:38 pm
by pavel
Yes, redirecting the blinking signal from LED0 to a GPIO pin requires a different FPGA image.

The connection to LED0 is defined on line 25 in led_blinker/block_design.tcl:
https://github.com/pavel-demin/red-pita ... gn.tcl#L25

Here is how to redirect the blinking signal to DIO0_P:
  • configure GPIO pins as output:

    Code: Select all

    # Delete input/output port
    delete_bd_objs [get_bd_ports exp_p_tri_io]
    
    # Create output port
    create_bd_port -dir O -from 7 -to 0 exp_p_tri_io
  • connect the blinking signal to GPIO pins:

    Code: Select all

    # Create port_slicer
    cell pavel-demin:user:port_slicer slice_0 {
      DIN_WIDTH 32 DIN_FROM 26 DIN_TO 26
    } {
      din cntr_0/Q
      dout exp_p_tri_io
    }

Re: Alpine Linux start up

Posted: Wed Aug 05, 2020 8:43 am
by kasaudio
Thanks!

Re: Alpine Linux start up

Posted: Thu Aug 06, 2020 8:20 pm
by kasaudio
Hello. I have another question. Where is this startup fpga image located? Thx.

Re: Alpine Linux start up

Posted: Thu Aug 06, 2020 8:58 pm
by pavel
It was in boot.bin in previous versions of my SD card images. In the latest version (20200628), there is no startup FPGA image. So, to rebuild boot.bin with a startup FPGA image, you'll need Makefile from previous versions of the repository.

Re: Alpine Linux start up

Posted: Mon Sep 07, 2020 9:00 pm
by kasaudio
Is there anything I can do to speed up boot time? I takes about half of a minute for my program to run as I power up RP?

BR, kas