Reset on Beaglebone Black has become unreliable/broken

[Konstantin Kletschke]

On Thu, Nov 28, 2024 at 01:02:01PM +0100, Konstantin Kletschke wrote:
> 
> > I'd suggest you enable CONFIG_DEBUG_LL and look if you see at least a >
> > character on the serial console output by the MLO.
> > 
> > If you don't see it, try moving these lines:
> > 
> >   am33xx_uart_soft_reset((void *)AM33XX_UART0_BASE);
> >   am33xx_enable_uart0_pin_mux();
> >   omap_debug_ll_init();
> >   putc_ll('>');
> > 
> > to the start of beaglebone_sram_init() and see if you get the > printed.
> > 
> > The point is making sure that barebox itself starts up before seeing where
> > it's getting stuck.
> 
> I will try that immediately.


I tried that.

make am335x_mlo_defconfig

Than I set:

CONFIG_HAS_DEBUG_LL=y
CONFIG_DEBUG_LL=y
CONFIG_DEBUG_OMAP_UART=y
CONFIG_DEBUG_AM33XX_UART=y
CONFIG_DEBUG_OMAP_UART_PORT=0

Then I removed the MTD driver, the old hack to set CONFIG_BAREBOX_MAX_IMAGE_SIZE 
to 0x2b400 somehow did not work, the image(s) did not boot at all. So
removing MTD allowed me to keep old 0x1b400 as SIZE and booted.

The I did 

make omap_defconfig 

and set

CONFIG_HAS_DEBUG_LL=y
CONFIG_DEBUG_LL=y
CONFIG_DEBUG_OMAP_UART=y
# CONFIG_DEBUG_OMAP3_UART is not set
CONFIG_DEBUG_AM33XX_UART=y
CONFIG_DEBUG_OMAP_UART_PORT=0

copied both images and booted, wich works.
At the start I see a glitch on the serial console like this:

~�W-�,-H]
                           ���k׋�ҫ�.LWC�C�C��arebox 2024.10.0-00150-g7a3cb7e6fd63-dirty #1 Thu Nov 28 14:35:15 CET 2024


Other baud rate?

However, reset via "reset" or S1 does not reveal a ">" or something. So
I moved the 4 lines in arch/arm/boards/beaglebone/lowlevel.c directly
below "void *fdt;", sadly this seems to not boot at all then, I see no
output on console anymore and the one blinking LED when barebox is idle
does not blink.

Regards
Konsti


-- 
INSIDE M2M GmbH
Konstantin Kletschke
Berenbosteler Straße 76 B
30823 Garbsen

Telefon: +49 (0) 5137 90950136
Mobil: +49 (0) 151 15256238
Fax: +49 (0) 5137 9095010

konstantin.kletschke at inside-m2m.de
http://www.inside-m2m.de 

Geschäftsführung: Michael Emmert, Derek Uhlig
HRB: 111204, AG Hannover