PS3: Strange issue with kexec and FreeBSD loader

[Phileas Fogg]

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.

regards