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

[Marek Vasut]

> On Wed, Jan 25, 2012 at 11:00:34PM +0100, Marek Vasut wrote:
> > > 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.
> 
> Yes and no. No, becaue you nor I have no Nokia's signing key(s) to sign
> SPL binary for OMAP's secure boot ROM. IIRC N950/N9 is even more strict
> regarding that, am I right?

Yea ... I was explained later how messed up it is ... so it'd probably be for 
the best now to replace NOLO with U-Boot SPL.

M
> 
> > > 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?
> 
> Butrom requires signed binary.
> 
> > > 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?
> 
> Any volunteers? (I own N900 too, ah, I own 3 of tham, damnit)
> 
> > > 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
> 
> All the best,
> S.