[U-Boot] Nokia N900: Broken comment after commit 278b90ce (configs: Migrate CONFIG_SYS_TEXT_BASE)

[Pali Rohár]

On Thursday 27 December 2018 14:10:26 Tom Rini wrote:
> On Thu, Dec 27, 2018 at 08:05:38PM +0100, Pali Rohár wrote:
> > On Thursday 27 December 2018 13:56:57 Tom Rini wrote:
> > > On Thu, Dec 27, 2018 at 07:45:15PM +0100, Pali Rohár wrote:
> > > 
> > > > Hi! Now I spotted that CONFIG_SYS_TEXT_BASE was moved/removed in commit
> > > > 278b90ce786f73faf29aa522d5d101e1da006378 from include/configs/nokia_rx51.h
> > > > file, but comment which described value for that macro is still on old
> > > > place. See diff:
> > > > 
> > > > http://git.denx.de/?p=u-boot.git;a=blobdiff;f=include/configs/nokia_rx51.h;h=c9901e52510110ea34bd1ac6bcdc2a90a9bada8d;hp=6312ed737c7104b331c11c8e88808fcc10654718;hb=278b90ce786f73faf29aa522d5d101e1da006378;hpb=7c8f00e484658c673d32d8422c96cb64bb571063
> > > > 
> > > > Tom, can you move also comment to place where is now
> > > > CONFIG_SYS_TEXT_BASE value for Nokia N900?
> > > 
> > > I'm a little confused.  We migrated the value set there to
> > > configs/nokia_rx51_defconfig where it's still 0x80008000 should it have
> > > been 0x80400000 ?  But that's not what the code was doing..
> > 
> > I do not know current state of U-Boot loading, but in past there was a
> > problem with Nokia N900. On N900, U-Boot image is loaded by Nokia's
> > bootloader at *random* address. And U-Boot needed to be at fixed base
> > address, therefore for N900 U-Boot low level init, there is a code which
> > moves U-Boot itself from *random* address to fixed based.
> 
> OK, and that should still be there, so I guess you need to dig a bit
> more to see what's wrong?

Yes, code is still there and seems it is working.

I just pointed that text comment, which was above CONFIG_SYS_TEXT_BASE
define, is for CONFIG_SYS_TEXT_BASE. It is for lines 29-34:

http://git.denx.de/?p=u-boot.git;a=blob;f=include/configs/nokia_rx51.h;h=6312ed737c7104b331c11c8e88808fcc10654718;hb=6312ed737c7104b331c11c8e88808fcc10654718#l29

So when you moved definition for CONFIG_SYS_TEXT_BASE value, then you
should have moved also comment which belongs to it :-)

It is just text comment, so it have no meaning for compiler. Just for
people who read code...

> > > > Anyway, now I tested in qemu n900 emulator U-Boot version from master
> > > > git branch and it is still working and able to boot 2.6.28 Maemo kernel!
> > > 
> > > Can you update .travis.yml to include running the n900 qemu setup?
> > > Thanks!
> > 
> > There are 3 problems:
> > 
> > 1) It needs Linaro arm version of qemu.
> > 
> > 2) It needs proprietary Nokia bootloader.
> > 
> > 3) It needs proprietary Nokia tool for creating bootable image for qemu.
> > 
> > Those images and tools probably disappeared from internet, but I still
> > have copies. License allows me to redistribute them for non-commercial
> > usage.
> > 
> > IIRC Linaro version of qemu is not available in distributions anymore,
> > so it would be needed to compile it from sources.
> 
> Ah, that is all unfortunate.

Looking at Travis configuration and it has sudo: required. So it is
running in virtual machine with full root access. So it should be
possible to compile or download pre-compiled binary of qemu into it.

Instructions how to prepare bootable U-Boot image in N900 qemu I sent
few years ago to mailing list, including license for those binaries.

Archive link:
https://lists.denx.de/pipermail/u-boot/2015-January/200171.html

If I get some answer that it is OK to use those proprietary binaries in
Travis, I can try to prepare N900 setup...

-- 
Pali Rohár
pali.rohar at gmail.com
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