On Thu, Feb 28, 2008 at 4:39 PM, Peter Stuge firstname.lastname@example.org wrote:
IMO an image is merely an instance of code. Fairly important distinction since "image" doesn't say where code in question came from.
let's call them targets then.
A simple example is DRAM timing.
well, we might never agree on this one, but here is an offer. If you want to prototype a dts which would have this info in it, and post it, let's take a look. I admit I know it can be done.
In general, control variables that are not intended to be changed, and which can cause undetectable problems, should remain in C code.
Disagree. Or - well - variables controlling _what_ exactly?
I introduced a term and did not define it.
How do we define variables, which are pretty special, such as CARBASE and dram timing? What's the name?
One example is to make a USB device look like a HID when in fact it is a UPS, because Windows programming is easier with HIDs or whatever.
If data is worth having in the device tree after boot and can never change at runtime - it belongs in the dts file at build time.
But almost all dram timing is unknown at runtime. We should design for that case.
stuge@n410c ~/co/v3/mainboard/pcengines/alix1c $ ls -l total 36 -rw-r--r-- 1 stuge stuge 1082 Feb 15 03:02 Kconfig -rw-r--r-- 1 stuge stuge 1330 Feb 15 03:02 Makefile -rw-r--r-- 1 stuge stuge 2517 Jan 24 04:14 cmos.layout -rw-r--r-- 1 stuge stuge 1717 Feb 29 01:16 dts -rw-r--r-- 1 stuge stuge 4437 Feb 29 01:16 initram.c -rw-r--r-- 1 stuge stuge 5936 Feb 15 03:02 irq_tables.c -rw-r--r-- 1 stuge stuge 1641 Feb 15 03:02 stage1.c stuge@n410c ~/co/v3/mainboard/pcengines/alix1c $
yea, but that code is really tricky due to mainboard inefficiencies and bugs and ... I think squeezing that very last bit out is going to be hard, and in the end, we might end up with the moral equivalent of GNU autoconfig - - sure, there's less code to see, but it's impossible to figure out what's going on.
Some times, 50 lines of special case code are better than 5000 lines of generic incomprehensible code.
Granted, K8 will be more interesting than Geode in this regard.
yes, let's see how k8 goes ...
I would like to have RAM components.
but it will only cover a trivial case -- it won't help most of our targets.
I just had another thought; I could probably be convinced that components don't need a dts. We're currently using dtc as a C preprocessor and there's not much point. But it doesn't do any harm either and I do not feel at all strongly about it.
The did not initially have a dts, but some people strong-armed me into doing it :-) In the end, I really like it.