Google SOC project tinyRTEMS

[Ray]

Hi, YanMiao, Joel Sherrill
I can offer some help in this ‘tiny’ project if any students interested in this.  
I believe Joel also implied that we also need add some configure options that a user can choose from when he|she want to enable the file system extra. If we accomplish the 3 topic Joel gave, RTEMS can be as small as uC-OSII in a 32-bit system.  
BTW, there might something else to do e.g. 8bit or 16bit Object-ID. In a word, we want the RTEMS a more configure-able system.  
We can break the work done and make some schedule for this.  
Just keep in mind, the application will be frozen in Mar.24, hurry up!




      
Thanks & Best Regards!    
      
Ray, rayx.cn at gmail.com     
2008-03-22      


========================= 
----- Receiving the following content -----   
=========================    
From:  Joel Sherrill      
Receiver:  阎淼      
Time: 2008-03-21, 21:17:43     
Subject: Re: Google SOC project tinyRTEMS     



     
>阎淼 wrote: 
>> Hello all, 
>> 
>>    I  am  interest  in tinyRTEMS project,  I have read the wiki page, 
>> and there are a lot of work has been done. I would like to know what 
>> is the direction of Tiny RTEMS project. 
>>    
>As stated, its goal is to shrink the minimum footprint of an RTEMS 
>executable 
>and a number of issues have already been addressed. Many of the issues are 
>fairly subtle and if you are new to RTEMS might be hard to figure out. 
> 
>One of the larger issues left and probably the only one worth even thinking 
>about as a GSOC project are the last three on the list. 
> 
>*disable newlib reentrancy (which might already be partially there) 
>*disable filesystem 
>*"device table filesystem". Functionality similar to how device names were 
>handled in RTEMS 4.0.0. Now we have a real POSIX style filesystem with 
>devices. Then we had a lookup table which mapped device names into 
>major/minor. So when you call open(), the device name isn't looked up 
>in a filesystem, it is looked up in a table of strings. 
> 
>Many of the TinyRTEMS ideas require the addition of application time 
>configuration to select the run-time capabilities. This one is a bit harder 
>because it spans the IO and filesystem infrastructure. You will have to 
>baseline 
>the size of the minimum, hello and ticker executables and work to eliminate 
>filesystem code you are replacing with a lighter alternative. 
> 
>In minimum, you want to push to have NO filesystem and IO code. 
> 
>In hello, you want the "device name lookup". 
> 
>Together the list above looks to be about 1/3-1/2 of the code in the minimum 
>executable on the ARM/Thumb rtl22xx_t BSP I use as a reference. So even 
>though 
>you might only save 8-12K total, you are moving from ~24K to 12-16K minimum. 
> 
>Does that make sense? 
> 
> 
>NOTE: Many space based systems using RTEMS do not use the filesystem and 
>hack it out anyway. This is just providing this reduced functionality 
>mode as 
>a real configure option. 
>> _______________________________________________ 
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>> rtems-users at rtems.com 
>> http://rtems.rtems.org/mailman/listinfo/rtems-users 
>>    
> 
> 
>--  
>Joel Sherrill, Ph.D.             Director of Research & Development 
>joel.sherrill at OARcorp.com        On-Line Applications Research 
>Ask me about RTEMS: a free RTOS  Huntsville AL 35805 
>   Support Available             (256) 722-9985 
> 
> 
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