[maemo-leste] Broken u-boot on n900 hw (possibly CONFIG_POSITION_INDEPENDENT)

[Ashish Shah]

Hi,

I am new. I am trying to figure out the right pogo pins to get in order to try to build a serial port for N900. But I am trying to decipher the docs in the wiki at the moment. 

Best,

-- 
  Ashish Shah

On Wed, Nov 9, 2022, at 2:33 PM, Pali Rohár wrote:
> On Wednesday 02 November 2022 01:08:26 Pali Rohár wrote:
>> On Friday 21 October 2022 21:09:55 Pali Rohár wrote:
>> > On Thursday 20 October 2022 22:06:58 Pali Rohár wrote:
>> > > On Monday 10 October 2022 23:30:21 Sicelo wrote:
>> > > > On Sun, Oct 09, 2022 at 09:33:17PM +0200, Pali Rohár wrote:
>> > > > > Hello!
>> > > > > 
>> > > > > Current u-boot from master branch does not work on n900 hw. It does not
>> > > > > show anything on display, there just nokia logo.
>> > > > > 
>> > > > > In qemu it is working fine and all tests are passing. Also in qemu is
>> > > > > display working without any problem.
>> > > > > 
>> > > > > Could you help me to debug it? Maybe something is printed to serial
>> > > > > console? Or maybe serial console could be used for printf-debugging?
>> > > > > 
>> > > > > I just figured out that disabling CONFIG_POSITION_INDEPENDENT u-boot
>> > > > > option make it working again. But it requires to restoring older version
>> > > > > of lowlevel_init.S file which does not depend on POSITION_INDEPENDENT:
>> > > > > 
>> > > > >     git checkout 7c4ad9821758f98db127e9d6864671c906c02d3b -- board/nokia/rx51/lowlevel_init.S
>> > > > > 
>> > > > > And also setting CONFIG_SYS_TEXT_BASE=0x80008000 (to some value in RAM).
>> > > > 
>> > > > Hi
>> > > > 
>> > > > I have a really crude serial console setup in place now, but very little
>> > > > time, and even less experience with u-boot. I should be able to do the
>> > > > tests for you on Saturday night (UTC+2). Perhaps over IRC might be a
>> > > > good idea, in case I need some hand-holding, and if you still need the
>> > > > help by then.
>> > > > 
>> > > > Regards
>> > > > Sicelo
>> > > 
>> > > Well, I do not know where to start or how to instruct somebody who is
>> > > not experienced with u-boot debugging. I think that the first step
>> > > should be to look if U-Boot prints something on the serial console or
>> > > not. If it prints then try to find via printf-driven-debugging place
>> > > where it stuck. If it does not print anything on the console then try to
>> > > setup debug early console, check if it prints something now and do same
>> > > type of debugging. And if even early debug console does not work then
>> > > probably initialize serial console directly in lowlevel_init.S file,
>> > > prints something to serial, then move code for printing to later stage
>> > > and try to figure out what is broken...
>> > 
>> > Early debug uart console can be enabled by configs/nokia_rx51_defconfig options:
>> > 
>> > CONFIG_DEBUG_UART=y
>> > CONFIG_DEBUG_UART_OMAP=y
>> > CONFIG_DEBUG_UART_SHIFT=2
>> > CONFIG_DEBUG_UART_BASE=0x49020000
>> > CONFIG_DEBUG_UART_CLOCK=48000000
>> > 
>> > And all debug verbose logs can be enabled by configs/nokia_rx51_defconfig options:
>> > 
>> > CONFIG_DM_DEBUG=y
>> > CONFIG_LOG=y
>> > CONFIG_LOGLEVEL=9
>> > CONFIG_LOG_MAX_LEVEL=9
>> > CONFIG_LOG_DEFAULT_LEVEL=9
>> > 
>> > By compiling via 'make u-boot.bin KCPPFLAGS=-DLOG_DEBUG'
>> 
>> Can somebody with serial console provide this debug output if there is
>> something useful?
>
> Can somebody help me with this?
>
>> > At least in qemu it is working and printing everything.
>> > 
>> > > Anybody else with serial console can look at it?
>> > > 
>> > > Or maybe look at the code if you spot some issue there?
> _______________________________________________
> Maemo-Leste mailing list
> Maemo-Leste at lists.dyne.org
> https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/maemo-leste