Re: Cross compiling MIPS kernel under x86

[David Daney <david.s.daney@gmail.com>]

On 05/27/2010 09:29 AM, octane indice wrote:
> Response to Dmitri Vorobiev<dmitri.vorobiev@gmail.com>  :
>> Just checked that the following steps result in a successful
>> build of a vanilla 2.6.34 vmlinux:
>>
> Thanks for taking the time to do it.
>
>> http://ftp.gnu.org/gnu/gcc/gcc-4.4.4/gcc-core-4.4.4.tar.bz2
>> tar jxf gcc-core-4.4.4.tar.bz2
>> cd ../build
>> ../src/gcc-4.4.4/configure --target=mips64-unknown-linux-gnu
>> --prefix=/work/tmp/zoo --disable-threads --disable-shared
>> --disable-multilib --disable-libgcc --disable-libmudflap
>> --disable-libssp --disable-libgomp
>> make
>
> It fails here with something related to stdc++. With adding a
> --enable-language=c it works. So the configure line I used is:
> ../gcc-4.4.4/configure --target=mips64-unknown-linux-gnu
> --prefix=/var/samba/mips --disable-threads --disable-shared
> --disable-multilib --disable-libgcc --disable-libmudflap --disable-libssp
> --disable-libgomp --enable-languages=c
>
>> make ARCH=mips cavium-octeon_defconfig
>> make ARCH=mips
>> CROSS_COMPILE=/work/tmp/zoo/bin/mips64-unknown-linux-gnu- vmlinux
>>
>> Hope that helps.
>>
> It helped me a lot, thank you. The kernel compiles fine.
> The kernel is very huge: 39MBytes (!).
> After a mips64-unknown-linux-gnu-strip, it downsized to 3.3MBytes.
> But that kernel doesn't boot.
>
> The system in the board I have uses in U-boot:
> ext2load ide 0 4000000 vmlinux
> bootoctlinux 4000000 (other args..)
>
> But when I replace the vmlinux file with mine called 'mips', it says:
> RSEC-K1# ext2load ide 0 4000000 mips
>
> 3362840 bytes read
> WARNING: Data loaded outside of the reserved load area, memory corruption
> may occur.
> WARNING: Please refer to the bootloader memory map documentation for more
> information.
> RSEC-K1# bootoctlinux 4000000
> ELF file is 64 bit
> Attempting to allocate memory for ELF segment: addr: 0xffffffff81100000
> (adjusted to: 0x0000000001100000), size 0x355c00
> Allocated memory for ELF segment: addr: 0xffffffff81100000, size 0x355c00
> Attempting to allocate memory for ELF segment: addr: 0xffffffff81343da0
> (adjusted to: 0x0000000001343da0), size 0x24
> Error allocating memory for elf image!
> ## ERROR loading File!
> RSEC-K1#
>

Early Octeon bootloaders cannot handle PT_NOTE program headers, I think 
that is what is biting you here.

If you can upgrade to an SDK-1.9 or later bootloader, I would recommend 
that.  Otherwise remove the PT_NOTE from your kernel image (the 
technique for doing this is left as an excise for the reader, but I have 
found that emacs hexl mode works well).

David Daney