[Buildroot] how to tune powerpc e500v2 cpus in BR

[Matias Garcia]

On 11-06-27 04:10 PM, raymond zhao wrote:
> On Sun, Jun 26, 2011 at 11:59 PM, Baruch Siach<baruch at tkos.co.il>  wrote:
>> Hi Raymond, Matias,
>> I'm also using the CodeSourcery toolchain for the e500v2 target (P1011), and I
>> figured out that I must pass -te500v2 to gcc at link time as well. Since there
>> is no generic way to add LDFLAGS options in Buildroot, I've posted the patch
>> at http://lists.busybox.net/pipermail/buildroot/2011-June/043668.html. Did you
>> find a better solution?
>>
>> baruch
> Hi, Baruch
> I took a look at the CodeSourcery. Looks it doesn't support uCLibc.
> Best regards,
> changbing
changbing: That's correct. You may find an older toolchain from them 
that uses uClibc, but you'll have to specify it yourself in the 
Buildroot config. I found a very small difference in size (<2MB) between 
uclibc and eglibc filesystems, but I'm using 32MB of flash just for the 
OS, so small is relative.

Baruch: I use the external toolchain wrapper introduced just before 
2011.05, but I had to patch it to add arbitrary options. I posted a 
couple of patches here, one that introduces a new option for selecting 
the sysroot when compiling the external wrapper, and another that simply 
passes the BR2_TARGET_OPTIMIZATIONS to the external wrapper, but they 
didn't get much attention.

I prefer the first method (new config option) because you can choose not 
to pass the optimizations at some later point for whatever reason, and 
thus use the wrapper only to select your sysroot.

Cheers,
Matias