Fwd: configuring memory size

[Ed Sutter]

Peter,
If you're looking for alternatives, then I also have a homegrown tool
that I use for this.  Very trivial, but does what I want, essentially
replacing a few sed/awk script with something that keeps everything to one
simple command line.
The purpose is slightly different than Thomas's, so you'll have several
options!  The purpose is to maintain the address information for the linker
file in my makefile as a variable.  Then the variable can be included in
CFLAGS if needed, along with being used as input to a template that creates
the final linker command file.
Anyway, the tool (called vsub) is included in the MicroMonitor source distribution
at http://www.microcross.com/html/micromonitor.html, or I can just send
you the source for that alone.
Lemme know if you want it.
Ed

Thomas Doerfler wrote:

> Hi,
> 
> just as an additional idea: Some years ago I used the C preprocessor to 
> generate linker command files from a template. The benefit was, that I 
> could have ONE header file defining address/size information for the C 
> compiler and for the linker.
> 
> Maybe this would also be convenient for Peter?
> 
> wkr,
> Thomas.
> 
> 
> D. Peter Siddons wrote:
> 
>> Hi Till,
>> The bsp is very similar to the uC5282. _M68k_Ramsize is copied from 
>> the linker value (_Ramsize) in bsp_start() (part of bspstart.c). I 
>> could easily check for the two possibilities here. Is that early enough?
>> Pete.
>>
>> Till Straumann wrote:
>>
>>> Eric Norum wrote:
>>>
>>>>>
>>>>> Looks like what I suggested won't work.   The linker complains if  
>>>>> the expressions in the  ORIGIN/LENGTH contain symbols even if 
>>>>> those  symbols have been defined before the assignment.
>>>>>
>>>>> I guess that you'll need to have two separate linkcmds files and  
>>>>> use something like
>>>>>     -Wl,-TlinkcmdsFor4MFlash
>>>>> or
>>>>>     -Wl,-TlinkcmdsFor16MFlash
>>>>
>>>>
>>>>
>>>>
>>> A much better solution would be enhancing the BSP so it does
>>> auto-detection. This has to be performed early enough,though.
>>>
>>> If an early detection is too cumbersome, then you can limit
>>> the initial size to a minimum, let's say 4M and increase the
>>> size later. In order to make the additional ram available to
>>> RTEMS (i.e., after the malloc heap/libc have been initialized)
>>> you have to implement a trivial 'sbrk()'. The only constraint
>>> is that the 'late ram'-portion of the heap to be added by sbrk()
>>> must be contiguous to the initial heap.
>>>
>>> You can look at powerpc/shared/bspstart which uses the
>>> two-staged heap approach for different reasons.
>>>
>>> HTH
>>> T.
>>>
>>>>>
>>>>>
>>>>>>
>>>>>> Eric Norum wrote:
>>>>>>
>>>>>>>> You need to pass the --defsym option to the linker.
>>>>>>>>
>>>>>>>> On the compile line, add something like
>>>>>>>>     -Wl,--defsym,_RamSize=0x10000000
>>>>>>>>
>>>>>>>> On Dec 2, 2005, at 10:50 PM, D. Peter Siddons wrote:
>>>>>>>>
>>>>>>>>> I have two boards which are identical except for the amounts  
>>>>>>>>> of  flash and RAM. The linkcmds file has definitions for 
>>>>>>>>> these   parameters like:
>>>>>>>>> _RamSize = DEFINED(_RamSize) ? _RamSize : 0x7f0000;
>>>>>>>>>
>>>>>>>>> so my question is, can I invoke a definition somewhere in the   
>>>>>>>>> application make process to override the one in linkcmds? If  
>>>>>>>>> so,  how and/or where?
>>>>>>>>>
>>>>>>>>> Pete.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>
>>>>> -- 
>>>>> Eric Norum <norume at aps.anl.gov>
>>>>> Advanced Photon Source
>>>>> Argonne National Laboratory
>>>>> (630) 252-4793
>>>>>
>>>>>
>>>>
>>>
>>>
> 
>