[U-Boot] [PATCH 00/14] Nokia RX-51 support

[Pali Rohár]

On Wednesday 25 January 2012 22:29:16 Marek Vasut wrote:
> > On Wednesday 25 January 2012 21:56:37 Marek Vasut wrote:
> > > > On Wednesday 25 January 2012 19:20:01 Marek Vasut wrote:
> > > > > So why not just replace the bootloader right away?
> > > > 
> > > > Booting process on n900:
> > > > 1. Omap bootrom
> > > > 2. Nokia X-Loader
> > > > 3. Nokia NOLO Bootloader
> > > > 4. Linux kernel
> > > > ...
> > > 
> > > To make it clear, I own N900 myself ;-)
> > > 
> > > > Nokia X-Loader and NOLO are stored in first nand part. It has size
> > > > 128kB. Nokia X-Loader is signed (size 14.5kB), so cannot be replaced.
> > > > NOLO bootloader is not signed (so theoretically can be replaced), but
> > > > size is limited to 113kB. I do not know how to compile U-Boot binary
> > > > with size < 113kB...
> > > > 
> > > > Size of part where is stored linux kernel has 2MB and it is enought
> > > > for
> > > > U-Boot with kernel image (~200kB + ~1.6MB). Also U-Boot can boot
> > > > kernel
> > > > from eMMC/SD.
> > > 
> > > You didn't answer my question, so again ... why can't you replace NOLO?
> > > Because there's the 113kb limit? Use SPL then.
> > 
> > I only tried to boot U-Boot in qemu wich increased boot part - but not
> > worked. (NOLO in qemu can boot u-boot without problems). So NOLO do some
> > extra work - which I do not know... Also limit is problem to test on real
> > n900.
> 
> What do you mean? Did you crack yours open? Can you connect JTAG to the
> device? I didn't check on mine.

I have no idea if N900 has JTAG. And I think that nobody cracked X-Loader yet.

NOLO bootloader can be replaced/flashed via flasher-3.5 app throw USB. Also 
when NOLO is damaged (or cleared/replaced) it can restored - coldflashed again 
via flasher-3.5.

What I tried:
I created mtd image where was X-Loader, NOLO and U-Boot. QEmu RX51 successfull 
booted this image and I got serial console and video screen output.

But when I created mtd image where was only X-Loader an U-Boot, QEmu RX51 was 
unable to boot (it freezed).

So NOLO executing some code which inilialize board or someting else which must 
be done in U-Boot board code. There is no documentation or info about NOLO, so 
I cannot create working NOLO replacement.

-- 
Pali Rohár
pali.rohar at gmail.com
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