[U-Boot] [PATCH][v4] powerpc/mpc85xx: SECURE BOOT- Add secure boot target for B4860QDS

[Scott Wood]

On Fri, 2014-03-07 at 10:30 -0800, York Sun wrote:
> On 03/07/2014 05:23 AM, Aneesh Bansal wrote:
> > Changes:
> > 1. L2 cache is being invalidated by Boot ROM code for e6500 core.
> >    So removing the invalidation from start.S
> > 2. Clear the LAW and corresponding configuration for CPC. Boot ROM
> >    code uses it as hosekeeping area.
> > 3. For Secure boot, CPC is configured as SRAM and used as house
> >    keeping area. This configuration is to be disabled once in uboot.
> >    Earlier this disabling of CPC as SRAM was happening in cpu_init_r.
> >    As a result cache invalidation function was getting skipped in
> >    case CPC is configured as SRAM.This was causing random crashes.
> > 
> > Signed-off-by: Aneesh Bansal <aneesh.bansal at freescale.com>
> > ---
> >  README                                     |  4 ++++
> >  arch/powerpc/cpu/mpc85xx/cpu_init.c        | 27 ++++++++++++++++++++++-----
> >  arch/powerpc/cpu/mpc85xx/start.S           |  3 ++-
> >  arch/powerpc/include/asm/fsl_secure_boot.h |  6 ++++++
> >  boards.cfg                                 |  1 +
> >  5 files changed, 35 insertions(+), 6 deletions(-)
> > 
> > Changes from v3:
> > Renamed the macro to indicate CPC configured as SRAM at U-boot entry to
> > CONFIG_SYS_CPC_SRAM 
> 
> Aneesh,
> 
> I understand you are trying to address the comment about when CPC needs to be
> disabled before initializing as normal CPC. But introducing CONFIG_SYS_CPC_SRAM
> seems even more confusing. Let's take one step back.
> 
> CPC as SRAM can be used for many reasons. There is only one reason we should
> keep it as SRAM, i.e. u-boot is indeed using SRAM as its final destination. For
> all other usages, we can safely reconfigure it as normal CPC after u-boot
> relocates itself into DDR. If u-boot's final destination is SRAM, it is a
> RAMBOOT. Can we use this condition to deal with CPC?

Even if CPC is the final destination, shouldn't RAMBOOT imply that DDR
has been initialized?

-Scott