PS3: Strange issue with kexec and FreeBSD loader

[Geert Uytterhoeven]

Hi Phileas,

On Sun, Feb 17, 2013 at 12:12 AM, Phileas Fogg <phileas-fogg at mail.ru> wrote:
> I found new clues about the problem.
>
> Normally the device tree memory segment is allocated at the top of the boot
> memory region. The boot memory size on the PS3 console is 128MB.
>
>
> root at ps3-linux:~# kexec -l loader.ps3
> segment[0].mem:0x131d000 memsz:262144
> segment[1].mem:0x135d000 memsz:36864
> segment[2].mem:0x7fff000 memsz:4096
>
> And the device tree is located at address 0x7fff000, it's the last page of
> the boot memory.
>
> I changed the kexec-tools and made it store the device tree just after the
> purgatory code which is located at address 0x135d000. Like here:
>
>
> root at ps3-linux:~# kexec -l loader.ps3
> segment[0].mem:0x131d000 memsz:262144
> segment[1].mem:0x135d000 memsz:36864
> segment[2].mem:0x1366000 memsz:4096   <---- new address of device tree
> segment
>
> And now the sha256 verification is always successful for the FreeBSD loader
> too.
> But still no idea what actually corrupts the device tree segment when it's
> located at the top of the boot memory region. And why it happens on Linux
> 3.7 and Linux 3.8 but not on Linux 3.3.8.

Have you looked at the actual data that ends up being written there?
It may give a clue...

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds