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.