[U-Boot] Cannot boot without monitor connected.

[U-Boot] Cannot boot without monitor connected.

[João M. S. Silva]

Hi,

I reported this to Olimex, but it seems related to u-boot.

I have this board, A20-OLinuXino-MICRO-4GB, running for about 4 years. I 
use it rarely to build executables in ARM format.

Some months ago, I found it down. I tried to boot it without success.

Then I connected a monitor to the HDMI port and was able to boot without 
problems. I updated the system and checked everything was OK but could 
not boot the board without the monitor connected.

I have now connected a serial debug cable to see what happens when the 
monitor is not connected and got this:

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U-Boot SPL 2016.11 (Dec 02 2016 - 16:51:49)
DRAM: 1024 MiB
CPU: 912000000Hz, AXI/AHB/APB: 3/2/2
Trying to boot from MMC1


U-Boot 2016.11 (Dec 02 2016 - 16:51:49 +0000) Allwinner Technology

CPU:   Allwinner A20 (SUN7I)
Model: Olimex A20-Olinuxino Micro
I2C:   ready
DRAM:  1 GiB
MMC:   SUNXI SD/MMC: 0, SUNXI SD/MMC: 1
*** Warning - bad CRC, using default environment

Setting up a 1024x768 vga console (overscan 0x0)
In:    serial
Out:   vga
Err:   vga
SCSI:  Target spinup took 0 ms.
AHCI 0001.0100 32 slots 1 ports 3 Gbps 0x1 impl SATA mode
flags: ncq stag pm led clo only pmp pio slum part ccc apst
Net:   eth0: ethernet at 01c50000
starting USB...
USB0:   ␀

§

Does anyone know what's wrong with the board?

Thanks.
-- 
João M. S. Silva