[U-Boot] arch/powerpc/cpu/ppc4xx/start.S: comment makes little sense

[U-Boot] arch/powerpc/cpu/ppc4xx/start.S: comment makes little sense

[Wolfgang Denk]

Dear Stefan,

I think this comment in arch/powerpc/cpu/ppc4xx/start.S needs a bit of
cleanup:

  51 /*  U-Boot - Startup Code for AMCC 4xx PowerPC based Embedded Boards
  52  *
  53  *
  54  *  The processor starts at 0xfffffffc and the code is executed
  55  *  from flash/rom.
  56  *  in memory, but as long we don't jump around before relocating.
  57  *  board_init lies at a quite high address and when the cpu has
  58  *  jumped there, everything is ok.
  59  *  This works because the cpu gives the FLASH (CS0) the whole
  60  *  address space at startup, and board_init lies as a echo of
  61  *  the flash somewhere up there in the memorymap.
  62  *
  63  *  board_init will change CS0 to be positioned at the correct
  64  *  address and (s)dram will be positioned at address 0
  65  */

All this makes pretty little sense to me.

Thanks.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
There are some things worth dying for.
	-- Kirk, "Errand of Mercy", stardate 3201.7

[U-Boot] arch/powerpc/cpu/ppc4xx/start.S: comment makes little sense

[Stefan Roese]

Hi Wolfgang,

On Sunday 21 November 2010 20:17:01 Wolfgang Denk wrote:
> I think this comment in arch/powerpc/cpu/ppc4xx/start.S needs a bit of
> cleanup:
> 
>   51 /*  U-Boot - Startup Code for AMCC 4xx PowerPC based Embedded Boards
>   52  *
>   53  *
>   54  *  The processor starts at 0xfffffffc and the code is executed
>   55  *  from flash/rom.
>   56  *  in memory, but as long we don't jump around before relocating.
>   57  *  board_init lies at a quite high address and when the cpu has
>   58  *  jumped there, everything is ok.
>   59  *  This works because the cpu gives the FLASH (CS0) the whole
>   60  *  address space at startup, and board_init lies as a echo of
>   61  *  the flash somewhere up there in the memorymap.
>   62  *
>   63  *  board_init will change CS0 to be positioned at the correct
>   64  *  address and (s)dram will be positioned at address 0
>   65  */
> 
> All this makes pretty little sense to me.

Agreed. I'll try to get a better description out soon.

Cheers,
Stefan

--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-0 Fax: (+49)-8142-66989-80 Email: office at denx.de