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From: Isaac Dunham <idunham@lavabit.com>
To: musl@lists.openwall.com
Subject: Re: microblaze: big endian or little endian (or both)?
Date: Tue, 16 Oct 2012 21:18:13 -0700	[thread overview]
Message-ID: <20121016211813.c8aaacb4.idunham@lavabit.com> (raw)
In-Reply-To: <20121017031344.GY254@brightrain.aerifal.cx>

On Tue, 16 Oct 2012 23:13:44 -0400
Rich Felker <dalias@aerifal.cx> wrote:

> On Tue, Oct 16, 2012 at 08:05:41PM -0700, Isaac Dunham wrote:
> > I'm trying to get stuff set up to run microblaze musl (first user
> > emulation, then system emulation if all goes well).
> > 
> > Anyhow, I'm wondering about whether to just use microblaze or if
> > microblazeel should work also (configure only says microblaze-*
> > which seems to imply that only the BE version is supported).
> 
> I don't see any reason little endian wouldn't work; I wasn't aware
> that it even existed. Aside from some workarounds for kernel struct
> layout and other ugly ABI issues on some archs, musl is completely
> endian-agnostic.
OK, thanks!

Somehow this gets me wondering about the endian.h issue...
#set ENDIAN in the first round to the per-arch default

case "$target" in 
  *el-* | *el) ENDIAN=BE ;;
  *eb-* | *eb) ENDIAN=LE ;;
  *) ;; #Just use the default endianness
esac
then, have ENDIAN determine whether to use the big-endian or little-endian header:

ln -s arch/$ENDIAN/endian.h include/bits/endian.h

clean: cleanendian

cleanendian:
	rm include/bits/endian.h

> > Other than that, I have a few random thoughts on microblaze systems
> > to experiment with:
> > 
> > 1. The xldk git repos have initrds for microblaze; if you inject
> > musl binaries in there, how does that work in qemu?
> 
> Haven't tried. I'd really rather figure out how to get rootfs-on-9p
> working and use that for all my qemu-system experimentation.

Yikes. That might take a while...
 
> > 2. Apparently it's possible (just barely) to get a Linux-capable
> > microblaze design onto a Spartan 6, which runs ~$90...
> 
> Nice. Any idea what the performance is like?
According to 
http://billauer.co.il/blog/2011/09/dma-capture-frame-grabbing-xilinx-fpga-linux-microblaze/ 
it's 70-100mhz effectively; microblaze seems to be extremely slow.

And yet they stuck a gigabit ethernet port on it.
-- 
Isaac Dunham <idunham@lavabit.com>



      reply	other threads:[~2012-10-17  4:18 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-17  3:05 Isaac Dunham
2012-10-17  3:13 ` Rich Felker
2012-10-17  4:18   ` Isaac Dunham [this message]

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