Re: [PATCH] MTD: OMAP2-NAND: Fix partition reading from board info

[David Brownell <david-b@pacbell.net>]

On Monday 04 August 2008, Lennert Buytenhek wrote:
> 
> I've never seen CPU endianity being hardwired in any ARM system ever
> -- but maybe OMAP is different.

I'll let TI answer that one, since I'm not going to look at docs for
all the ARM's I've ever used.

My observation stands *REGARDLESS* of whether endianness was fixed in
hardware, bootloader, or kernel ... and in any case, with very few
exceptions (not including OMAP), Linux uses ARMs in LE mode:

  ~/kernel/linux-2.6/arch/arm/configs$ grep ENDIAN * | egrep -v '#' |egrep -v OHCI
  ixp2000_defconfig:CONFIG_ARCH_SUPPORTS_BIG_ENDIAN=y
  ixp2000_defconfig:CONFIG_CPU_BIG_ENDIAN=y
  ixp23xx_defconfig:CONFIG_ARCH_SUPPORTS_BIG_ENDIAN=y
  ixp23xx_defconfig:CONFIG_CPU_BIG_ENDIAN=y
  ixp4xx_defconfig:CONFIG_ARCH_SUPPORTS_BIG_ENDIAN=y
  ixp4xx_defconfig:CONFIG_CPU_BIG_ENDIAN=y
  ~/kernel/linux-2.6/arch/arm/configs$  ls | wc -l
  105
  ~/kernel/linux-2.6/arch/arm/configs$ 

To repeat:  there's no point in having the words byteswapped when
writing, then again when reading, like this driver does.  All that
does is ensure slow I/O paths.  Were you disagreeing with that main
point?  Or just quibbling about where any unusual big-endianness
might come from?

- Dave