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

Marek Vasut
2012-01-25T22:00:34Z

> 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.

What do you mean, you don't need xloader, u-boot SPL can replace it.
>
> 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.

I know. So ... ? Basically you can use the TI flashes too since it all goes
through the bootrom, right?
>
> 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).

Why? Where? You know you can debug U-Boot in QEMU with GDB and diag the problem
properly?

>
> 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.

Yes you can, either observe it or disas it.

M