Re: [PATCH] Detect endian in cpio fs

[Vladimir 'phcoder' Serbinenko]

On Fri, Aug 28, 2009 at 2:20 PM, Bean<address@hidden> wrote:
> On Fri, Aug 28, 2009 at 8:03 PM, Vladimir 'phcoder'
> Serbinenko<address@hidden> wrote:
>> On Thu, Aug 27, 2009 at 10:27 AM, Bean<address@hidden> wrote:
>>> Hi,
>>>
>>> This patch allows to access big/little endian cpio archive from
>>> big/little endian machine.
>> Quick glance showed that you use swap_bytes. Could you use
>> grub_*_to_cpu* instead? This would simplify the future maintainability
>> if someone decides to port to a very special platform (e.g.
>> mixed-endian) since code would be uniform
>
> Hi,
>
> Actually it's not correct to use grub_*_to_cpu*. The code works by
> first assuming cpio uses the same endian of host cpu, if not, swap it
> and try the other endian. This method works for big/little endian cpio
> on big/little endian machine. It's possible to achieve the same result
> with a combination of #ifdef and grub_*_to_cpu*'s, but it's not as
> simple as this and generate more code than necessary.
>
Why is it more expensive than first try le and then be? What about
having 2 modules cpio_le and cpio_be?
> --
> Bean
>
> gitgrub home: http://github.com/grub/grub/
> my fork page: http://github.com/bean123/grub/
>
>
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>



-- 
Regards
Vladimir 'phcoder' Serbinenko

Personal git repository: http://repo.or.cz/w/grub2/phcoder.git