Re: Larkin should like The Unix Haters Handbook



John Larkin <jjlarkin@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

On Fri, 05 Jun 2009 18:03:28 GMT, nico@xxxxxxxxxxx (Nico Coesel)
wrote:

John Larkin <jjlarkin@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

On Fri, 5 Jun 2009 08:47:03 -0500, "Tim Williams"
<tmoranwms@xxxxxxxxxxx> wrote:

http://simson.net/ref/ugh.pdf

About halfway through, they talk about C and C++, too. I must say, the
similarities and pitfalls are astounding, and spot on to John's lamentations
over C and such.

Noteworthy: it's about Unix, not Linux or any of the myriad derivatives. I
wonder how some of the popular modern forks, like the popular Debian,
differ. I'm willing to bet they still inherit most of the 1MLOC+ of refuse
from the previous 30 years of development though.

Tim

Cool; I'll make time to read that soon.

We just hired our first official Software Engineer (we aren't allowed
to call him a programmer) for this Linux box we're doing.

So we got the PLX demo board (for their PCIe interface chip) and their
Linux drivers. The drivers don't work, of course. So, in time-honored
fashion, we are now recompiling both the driver *and* the Linux
kernel, together, to try to resolve the incompatibilities.

http://xkcd.com/456/

Yup. After about a man-month (which is about 250 hours in this biz)
it's mostly working. I don't often spend that sort of time on an
entire, bare-metal embedded product.

Perhaps hire someone better. At a previous employer we hired a real
Linux expert. A driver for 'our' PCI card only took him 2 or 3 days.

They don't get much better than this guy. Trust me on that.

Nobody is perfect... Perhaps it takes a more hardware oriented guy.
The Linux guru I worked with connected the parallel port to an Agilent
MSO. He used that to debug the driver in realtime by writing state
information to the printer port. The ability to load/unload a Linux
kernel driver makes it possible to have very short turn-around times.
No need to recompile the entire kernel or reboot the machine. It just
shouldn't take that long to get a driver up and running.

Lately I have been doing a lot of Linux kernel hacking myself for a
product which uses Linux on an embedded and I must say most stuff in
the Linux kernel is pretty straightforward.

But the PLX chip isn't. The "data sheet" is a 592 page PDF file.

Depends on the writers. Infineon (formely Siemens) can spend over 300
pages on what Zarlink (formerly Mitel) can explain using only 20
pages. Both describing similar chips.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
"If it doesn't fit, use a bigger hammer!"
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