Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A20 => Topic started by: luis on April 25, 2014, 11:00:25 PM

Title: Can't boot from SD card
Post by: luis on April 25, 2014, 11:00:25 PM
Hi.

Received the board (A20-olinuxino-micro with 4Gb onboard) last week. I can start from the onboard android just connecting a usb cable.

I downloaded the debian (version 7) image and have written it to an 8Gb sd card, from linux with the dd command.

I followed all the instructions. I insert the card, then press and hold the 'recovery' button then plug in a 12v > 1A power supply (I have tried with 2 different power supplies), then release the 'recovery' button but the board only shows a single red led on and nothing happens. Also tried to plug in the usb cable after these steps but still nothing happens.

I am missing something?
Can anyone help?

Thanks!

Luis 
Title: Re: Can't boot from SD card
Post by: Lurch on April 26, 2014, 11:39:15 AM
What's with the recovery button?
I just apply 12V @ 1,5A to the barrel connector and it boots from SDCard.
If I remove the SDCard and do the same it boots Android.
Are you using a battery?
Do you have a USB-TTL adapter to connect UART0 to a PC and use a terminal program to see the boot messages?
Title: Re: Can't boot from SD card
Post by: JohnS on April 26, 2014, 12:24:03 PM
That button may be stopping it booting from SD and instead forcing FEL mode.

John
Title: Re: Can't boot from SD card
Post by: vinifr on April 27, 2014, 05:38:36 PM
QuoteI followed all the instructions. I insert the card, then press and hold the 'recovery' button then plug in a 12v > 1A power supply

Sorry, I dont understand. As far as I know is not required to hold any button to boot from uSD. You do this only when you record another image on NAND memory.

I agree with JohnS. You are entering in FEL mode, but I repeat, this is not necessary, if you want to boot from the uSD!

Put uSD and just wait.  ;)

Ah, a tip: It is very very important to have a cable USB-TTL or something similiar to see the output of UART0.
Title: Re: Can't boot from SD card
Post by: luis on April 28, 2014, 01:19:01 AM

I was pressing the RECOVERY button because I was following these instructions:
https://www.olimex.com/wiki/A20-OLinuXino-MICRO#How_do_I_write_the_official_Android_image_to_a_micro_SD_card_for_my_A20_board.3F (https://www.olimex.com/wiki/A20-OLinuXino-MICRO#How_do_I_write_the_official_Android_image_to_a_micro_SD_card_for_my_A20_board.3F)

I found the problem: I was using the SD 2 socket and not the SD 1 (on the top face of the board).

Now everything works.

Thanks for your answers.
Luis
Title: Re: Can't boot from SD card
Post by: vinifr on April 28, 2014, 04:01:31 AM
Ah, sorry. I thought you were talking about Linux.  :o