Re: Arch/mips/kernel/vpe.c

[Ralf Baechle <ralf@linux-mips.org>]

On Sat, Jan 05, 2008 at 05:05:46PM +0000, Thiemo Seufer wrote:

> > 	I am working on MIPS34KC with APRP kernel and I use uclibc
> > gccc-3.4.4 to build applications to run on VPE1. The present
> > implementation of VPE loader is limited to a few relocation types which
> > are used when mips_sde compiler is used. However, the relocatable binary
> > churn out from my uclibc-gcc-3.4.4 has more other relocation types than
> > the ones defined in arch/mips/kernel/vpe.c, especially those with GOT
> > relocation types. I have taken a look at the System V ABI Third Edition
> > but if anybody has any code reference and pointers to how each
> > relocation types should be implemented in C-code, it would be very
> > helpful.
> 
> The most likely place to look at would be the binutils source code. That
> said, you can probably get away without enhancing the VPE loader by using
>   a) fully linked (non-relocatable) executables, or
>   b) non-PIC code, like SDE does
> 
> Regardless of your choice, you will have to make sure the uclibc toolchain
> doesn't use any libraries which need Linux facilities, as the bare-metal
> environment on VPE1 doesn't provide them. For that reason I believe you
> are better of with SDE or a similiar mips*-elf configured toolchain.

I'm tempted to replace the existing vpe loader with something like the 2.4
version of insmod which does all the relocation handling in userspace and a
device file which make the vpe memory available to userspace for the loader
to write to.  Or something like spufs.

  Ralf