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Groups > comp.os.linux.embedded > #101

Re: Reading the Riot Act To ARM's developers

Date 2012-02-11 15:16 +0100
From David Brown <david.brown@removethis.hesbynett.no>
Newsgroups comp.os.linux.advocacy, comp.os.linux.embedded
Subject Re: Reading the Riot Act To ARM's developers
References <WGiYq.100467$WX2.28685@newsfe28.ams2> <4iah09-1p2.ln1@spankydtr.localhost.net> <PYqZq.3558$FY5.2955@newsfe10.ams2>
Message-ID <_ImdnTsu9qPQ5avSnZ2dnUVZ8gCdnZ2d@lyse.net> (permalink)

Cross-posted to 2 groups.

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On 11/02/12 10:58, 7 wrote:
> Kelsey Bjarnason wrote:
>
>> [snips]
>>
>> On Tue, 07 Feb 2012 23:43:43 +0000, 7 wrote:
>>
>>> Typically the CMSIS library forces you to write code using hard coded
>>> numbers. So you want to set some flag to enable an interrupt it would
>>> read something like
>>>
>>> SYSCON->INT |= (1<<4)
>>>
>>> Here is the crunch, who the hell is going to know if its the 4th bit or
>>> the 14th bit when you got a million of these lines of code?
>>>
>>> Shortest possible answer NOBODY. Not even you!!!!!!!!!
>>>
>>> And then you change CPU, and something changes in hardware, how will you
>>> know what to look for - you gonna search for "4" all throughout the
>>> code?????
>>
>>
>> Are you actually using a tool so bad it doesn't let you define your own
>> symbols?
>>
>> define	INT_XMA	(1<<  4)
>>
>> ...
>>
>> SYSCON->INT |= INT_XMA
>>
>> Need to change INT_XMA?  Change it in one place, *every* usage of it
>> changes.  If your development tools can't cope with this - and, ideally,
>> with include files - then you should consider using a macro preprocessor
>> to generate the compilable code from the maintainable code.
>>
>> Either way, has nothing to do with ARM, per se; just to do with an
>> apparently crippled toolchain and/or a developer who can't look beyond
>> the trivial tool to see possible solutions.
>
>
> The point I was making has been snipped.
>
> The way I do it is independent of all these issues and much more verbose.
>
>
> #define INT_XMA (1<<  4)
> #define ENABLE_RS232  SYSCON->INT |= INT_XMA
>
>
> The problem I am having is what does that '4' mean. Is it 4 or 14 or
> something else? I need a datasheet. Thats just crap programming.
>
> What I want to be able to do is
>
> #define ENABLED 1
> #define ENABLE_RS232_INTERRUPT  SYSCON.INT.INT_XMA = ENABLED
>
> or something similar which is what PIC libraries do.
> The flag has been defined for you so that you don't have to figure
> out INT_XMA is (1<<  4) or (1<<  14) sifting through a datasheet.
> When a CPU is changed, the magic of giving names to flags
> still works and saves a lot of time when checking.
>
>
> If you care to look at the support forums and sample code,
> you will also find most programmers set multiple flags
> with one setting.
> That makes the problem 100 times worse because its even more
> work trying to figure out which flags have been set.
>
> The programmers who wrote the CMSIS libraries should be shot
> and replaced with programmers who are a little more wiser.
> They should spend more time with compiler writers that support
> ARM to make sure that everybody sings from the same song sheet.
>
>

I would recommend a useful little feature that most programming 
languages support - "comments".

Magic numbers are a problem if the same number is used several times in 
a program, or if they are used without explanatory comments.  But with a 
comment explaining what "(1 << 4) | (1 << 14)" means in this situation, 
it is perfectly good programming.

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Thread

Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-07 23:43 +0000
  Re: Reading the Riot Act To ARM's developers cassiope <fpm@u.washington.edu> - 2012-02-08 09:51 -0800
    Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-08 19:29 +0000
      Re: Reading the Riot Act To ARM's developers David Brown <david.brown@removethis.hesbynett.no> - 2012-02-08 21:37 +0100
        Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-08 21:52 +0000
          Re: Reading the Riot Act To ARM's developers "Arie de Muynck" <nospam@nospam.com> - 2012-02-09 08:09 +0100
            Re: Reading the Riot Act To ARM's developers David Brown <david@westcontrol.removethisbit.com> - 2012-02-09 10:50 +0100
              Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-09 21:51 +0000
                Re: Reading the Riot Act To ARM's developers "Ezekiel" <zeke@nosuchemail.com> - 2012-02-10 15:41 -0500
          Re: Reading the Riot Act To ARM's developers "Ezekiel" <zeke@nosuchemail.com> - 2012-02-09 07:44 -0500
          Re: Reading the Riot Act To ARM's developers Bob Hauck <postmaster@avalanche.org> - 2012-02-09 08:28 -0500
            Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-09 23:38 +0000
              Re: Reading the Riot Act To ARM's developers David Brown <david@westcontrol.removethisbit.com> - 2012-02-10 09:26 +0100
                Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-10 19:51 +0000
                Re: Reading the Riot Act To ARM's developers David Brown <david.brown@removethis.hesbynett.no> - 2012-02-10 21:51 +0100
                Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-10 23:37 +0000
                Re: Reading the Riot Act To ARM's developers Grant Edwards <invalid@invalid.invalid> - 2012-02-13 15:11 +0000
                Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-13 21:30 +0000
    Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-08 19:29 +0000
      Re: Reading the Riot Act To ARM's developers Kelsey Bjarnason <kbjarnason@gmail.com> - 2012-02-10 21:25 -0800
        Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-11 09:27 +0000
  Re: Reading the Riot Act To ARM's developers Kelsey Bjarnason <kbjarnason@gmail.com> - 2012-02-10 21:22 -0800
    Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-11 09:58 +0000
      Re: Reading the Riot Act To ARM's developers David Brown <david.brown@removethis.hesbynett.no> - 2012-02-11 15:16 +0100
        Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-12 00:56 +0000
          Re: Reading the Riot Act To ARM's developers David Brown <david.brown@removethis.hesbynett.no> - 2012-02-12 10:24 +0100
            Re: Reading the Riot Act To ARM's developers "Ezekiel" <zeke@nosuchemail.com> - 2012-02-12 08:21 -0500
            Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-12 19:12 +0000
              Re: Reading the Riot Act To ARM's developers Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2012-02-13 08:54 +0200
                Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-13 21:37 +0000
                Re: Reading the Riot Act To ARM's developers Grant Edwards <invalid@invalid.invalid> - 2012-02-13 22:07 +0000
                Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-13 23:31 +0000
                Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-13 23:31 +0000
                Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-13 23:31 +0000
                Re: Reading the Riot Act To ARM's developers Peter Köhlmann <peter-koehlmann@t-online.de> - 2012-02-14 10:35 +0100
                more troll spew from eternal-september.org 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-14 11:27 +0000
                Re: more troll spew from eternal-september.org Peter Köhlmann <peter-koehlmann@t-online.de> - 2012-02-14 13:17 +0100
                Re: more troll spew from eternal-september.org Big Steel <SteelOne@SteelOne.com> - 2012-02-14 07:55 -0500
                Re: more troll spew from eternal-september.org GreyCloud <mist@cumulus.com> - 2012-02-14 11:18 -0700
                Re: more troll spew from eternal-september.org GreyCloud <mist@cumulus.com> - 2012-02-14 11:18 -0700
                Re: more troll spew from eternal-september.org Foster <frankfoster50@yahoo.com> - 2012-02-14 09:09 -0500
                Re: Reading the Riot Act To ARM's developers Foster <frankfoster50@yahoo.com> - 2012-02-14 08:38 -0500
                Re: Reading the Riot Act To ARM's developers GreyCloud <mist@cumulus.com> - 2012-02-14 11:19 -0700
                Re: Reading the Riot Act To ARM's developers GreyCloud <mist@cumulus.com> - 2012-02-14 11:17 -0700
                Re: Reading the Riot Act To ARM's developers Peter Köhlmann <peter-koehlmann@t-online.de> - 2012-02-14 21:50 +0100
                Re: Reading the Riot Act To ARM's developers GreyCloud <mist@cumulus.com> - 2012-02-14 15:42 -0700
                Re: Reading the Riot Act To ARM's developers Peter Köhlmann <peter-koehlmann@t-online.de> - 2012-02-14 23:56 +0100
                more troll spew 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-14 22:34 +0000
                Re: more troll spew GreyCloud <mist@cumulus.com> - 2012-02-15 00:12 -0700
                Re: more troll spew Foster <frankfoster50@yahoo.com> - 2012-02-15 08:29 -0500
                Re: more troll spew GreyCloud <mist@cumulus.com> - 2012-02-15 11:22 -0700
                Re: more troll spew 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-15 23:03 +0000
                Re: more troll spew Foster <frankfoster50@yahoo.com> - 2012-02-15 18:07 -0500
                Re: more troll spew GreyCloud <mist@cumulus.com> - 2012-02-15 16:36 -0700
                Re: more troll spew GreyCloud <mist@cumulus.com> - 2012-02-15 16:34 -0700
                Re: Reading the Riot Act To ARM's developers Kelsey Bjarnason <kbjarnason@gmail.com> - 2012-02-14 20:06 -0800
                Re: Reading the Riot Act To ARM's developers chrisv <chrisv@nospam.invalid> - 2012-02-15 07:20 -0600
                Re: Reading the Riot Act To ARM's developers "Ezekiel" <zeke@nosuchemail.com> - 2012-02-15 11:20 -0500
                Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-15 20:15 +0000
                Re: Reading the Riot Act To ARM's developers "Ezekiel" <zeke@nosuchemail.com> - 2012-02-15 15:26 -0500
                Re: Reading the Riot Act To ARM's developers Peter Köhlmann <peter-koehlmann@t-online.de> - 2012-02-15 21:38 +0100
                more troll spew 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-15 22:56 +0000
                Re: more troll spew Foster <frankfoster50@yahoo.com> - 2012-02-15 18:00 -0500
                Re: more troll spew Peter Köhlmann <peter-koehlmann@t-online.de> - 2012-02-16 00:06 +0100
                Re: more troll spew Snit <usenet@gallopinginsanity.com> - 2012-02-15 16:28 -0700
                Re: more troll spew 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-16 19:48 +0000
                Re: more troll spew Peter Köhlmann <peter-koehlmann@t-online.de> - 2012-02-16 20:57 +0100
                Re: more troll spew cc <scatnubbs@hotmail.com> - 2012-02-16 12:10 -0800
                Re: more troll spew 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-16 20:43 +0000
                Re: more troll spew Peter Köhlmann <peter-koehlmann@t-online.de> - 2012-02-16 21:45 +0100
                Re: more troll spew 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-16 21:20 +0000
                Re: more troll spew Big Steel <SteelOne@SteelOne.com> - 2012-02-15 19:37 -0500
              Re: Reading the Riot Act To ARM's developers David Brown <david@westcontrol.removethisbit.com> - 2012-02-13 09:12 +0100
      Re: Reading the Riot Act To ARM's developers Kelsey Bjarnason <kbjarnason@gmail.com> - 2012-02-11 10:34 -0800
      Re: Reading the Riot Act To ARM's developers Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-02-25 10:18 +0200
        Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-25 19:34 +0000
          Re: Reading the Riot Act To ARM's developers Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-02-27 15:52 +0200
            Re: Reading the Riot Act To ARM's developers David Brown <david.brown@removethis.hesbynett.no> - 2012-02-27 22:04 +0100
              Re: Reading the Riot Act To ARM's developers Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-03-03 02:04 +0200
                Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-03-03 00:20 +0000
                Re: Reading the Riot Act To ARM's developers GreyCloud <cumulus@mist.com> - 2012-03-03 00:06 -0700
                Re: Reading the Riot Act To ARM's developers Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-03-03 15:22 +0200
                Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-03-04 12:28 +0000
                Re: Reading the Riot Act To ARM's developers "Ezekiel" <zeke@nosuchemail.com> - 2012-03-04 09:15 -0500
                Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-03-04 21:29 +0000
            While( Ch ) if ( Ch‑1 <= 32 ) *P -= 32 ;  Jeff-Relf.Me <x@x.Invalid> - 2012-02-28 05:52 -0800
              Re: While( Ch ) if ( Ch‑1 <= 32 ) *P -= 32 ;  Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-03-03 02:09 +0200
        Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-25 19:34 +0000

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