[v3, 3/7] powerpc: enable the relocatable support for the fsl booke 32bit kernel

Kevin Hao haokexin at gmail.com
Thu Jan 9 12:39:43 EST 2014


On Wed, Jan 08, 2014 at 06:02:19PM -0600, Scott Wood wrote:
> On Wed, Jan 08, 2014 at 10:42:35AM +0800, Kevin Hao wrote:
> > On Tue, Jan 07, 2014 at 05:46:04PM -0600, Scott Wood wrote:
> > > Oh.  I think it'd be more readable to do "offset = start -
> > > memstart_addr" and add offset instead of subtracting it.
> > 
> > Yes, I agree. The reason that I use "offset = memstart_addr - start" is that
> > it seems "memstart_addr" is always greater than "start" when we are booting
> > a kdump kernel with a kernel option like "crashkernel=64M at 80M". :-)
> > 
> > > 
> > > Also, offset should be phys_addr_t -- even if you don't expect to
> > > support offsets greater than 4G on 32-bit, it's semantically the right
> > > type to use.  Plus, "int" would break if this code were ever used with
> > > 64-bit.
> > 
> > I thought about using phy_addr_t for the "offset" originally but gave it up
> > for the following reasons:
> >   * It will not be greater than 4G.
> >   * We have to use the ugly #ifdef CONFIG_PHYS_64BIT in restore_to_as0().
> >   * Need more registers for arguments for restore_to_as0().
> > 
> > Of course you can change it to phys_addr_t if you prefer.
> 
> Here's the diff I made when applying (also changed the subf in patch 9 to
> add)

Looks fine to me. I also done a boot test and it works pretty well.
Thanks Scott.

Kevin
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