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On 06/28/2017 18:29, James Le Cuirot wrote: |
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> On Wed, 28 Jun 2017 17:52:26 -0400 |
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> Mike Gilbert <floppym@g.o> wrote: |
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> |
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>> On Tue, Jun 27, 2017 at 6:44 PM, James Le Cuirot <chewi@g.o> wrote: |
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>>> I am therefore proposing a new global big-endian flag. This could be |
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>>> masked by default and unmasked + forced in the relevant profiles under |
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>>> arch. I will apply this according to the mapping defined in tc-endian of |
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>>> toolchain-funcs.eclass. |
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> |
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> I've just been putting the patch together. I made it slightly simpler |
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> by masking *and* forcing it by default so that it only needs to be |
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> unmasked were necessary. |
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> |
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>> A possible alternative would be to create a new USE_EXPAND variable |
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>> for this. That would allow for easier expansion in case we ever |
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>> support something other than big/little endian machines. |
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> |
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> That way madness lies? Wikipedia talks about middle-endian as being the |
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> catch all for other random orderings that have appeared over the years |
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> but I don't think any of them were used on a system-wide basis. I can't |
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> imagine Linux ever supporting such a thing. Unless you're talking about |
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> dealing with soft vs hard float here too? |
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|
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As far as I know, Linux only supports big-endian and little-endian systems, |
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along with supporting a fairly-wide variety of platforms and architectures, |
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beaten really only by NetBSD. If NetBSD lacks anything for middle-endian, then |
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it's probably safe to ignore it. |
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|
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That said, Wikipedia doesn't offer much on the nature of middle-endian (which |
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is called "PDP-endian"), except to state that "The ARM architecture can also |
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produce this format when writing a 32-bit word to an address 2 bytes from a |
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32-bit word alignment." |
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https://en.wikipedia.org/wiki/Endianness#Middle |
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|
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And this resource: |
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http://unixpapa.com/incnote/byteorder.html |
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|
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Recommends to ignore middle-endian, as it believes no processor was ever |
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implemented that stored integers in middle-endian format. |
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|
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-- |
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Joshua Kinard |
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Gentoo/MIPS |
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kumba@g.o |
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6144R/F5C6C943 2015-04-27 |
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177C 1972 1FB8 F254 BAD0 3E72 5C63 F4E3 F5C6 C943 |
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|
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"The past tempts us, the present confuses us, the future frightens us. And our |
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lives slip away, moment by moment, lost in that vast, terrible in-between." |
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|
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--Emperor Turhan, Centauri Republic |
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