Conditional assembly was Re: Preventing the mixing of armhf packages
On Thu, Apr 26, 2012 at 10:40:26PM +0100, Wookey wrote:
> The right way to do this is with HWCAPS bits to identify whether the
> hardware can run v7 binaries and for dpkg to refuse to install stuff
> that won't run.
On reading this thread I was reminded of an issue I had when writing
code using the GNU ARM assembler (sorry if this is off-topic here,
but the GNU ARM list isn't very useful)
Anyhow, I wanted to conditional assemble dependent upon processor
type. The one case I can remember was the use of the 'rev'
instruction for converting big-endian to little-endian and vice
versa. It is supported in ARM v6, but my sheevaplug has a 5TE, so I
had to do all the bit manipulation by hand.
If I ever were to want to write "generic" assembler code for any ARM
processor such that the most efficient instructions were assembled,
can anyone point me at how to do so using the GNU assembler?
I guess since it is off-topic here, off list replies would be
"If you propose to speak, always ask yourself,
is it true, is it necessary, is it kind?"