[PATCH] lib/decompress_unxz.c: removing all memory helper functions
Lasse Collin
lasse.collin at tukaani.org
Fri May 25 04:34:32 EDT 2012
On 2012-05-24 T Makphaibulchoke wrote:
> The patch cleans up the file lib/decompress_unxz.c by removing all
> memory helper functions, e.g., memmove. By doing so, any
> architecture's preboot environment supporting the XZ decompression
> needs to define its own copy of any of the missing memory helper
> functions.
Is it best to copy these functions to each arch, or would it be better
to have a shared file from which these functions could be pulled for
multiple archs? I wasn't sure when I wrote decompress_unxz.c, which is
why I put the extra functions there as a temporary solution.
> Adding both the missing memmove and memcmp functions, required by the
> XZ decompressor, to the sh preboot environment.
>
> Adding the missing memmove function, required by XZ decompressor, to
> the x86 preboot environment.
These already have memcpy. It can save a few bytes if one reused
memmove as memcpy when using XZ compression. I got a difference of 48
bytes on x86_64.
Adding memmove to string.c on x86 means that memmove is included in the
kernel image even when memmove isn't needed. With gzip compression I
got 128 bytes bigger image on x86_64 after adding the unneeded memmove
to string.c.
I don't know if those size increases matter in practice.
> + * To support XZ-decompressed file in preboot environment, the
s/XZ-decompressed/XZ-compressed/ :-)
--
Lasse Collin | IRC: Larhzu @ IRCnet & Freenode
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