[En-Nut-Discussion] Code size to large for one flash bank

[Andre Riesberg]

Bernd Walter schrieb:
> On Mon, Dec 27, 2010 at 10:37:13AM +0100, Andre Riesberg wrote:
>   
>> Hello all!
>>
>> The codes size of my application grows and exceeds the limit of 262144 
>> bytes.
>> Now I got the message from OpenOCD:
>> "Warn: writing 262144 bytes only ??? as image section is 270228 bytes and 
>> bank is only 262144 bytes."
>> I use a board like the EIR with ARM7TMI and the Turtelizer2 with the 
>> command line: "C:\ethernut-4.8.3\nut\tools\win32\openocd.exe -f 
>> interface\turtelizer2.cfg -f eir.cfg".
>>
>> So, I have two questions:
>>
>> How I have to modify the config scripts to support the second flash bank?
>>     
>
> IIRC you just need to setup the bigger rom size in the loader script.
> >From the software point of view this is just a single large rom space.
>   
I use the "at91sam7se512_rom.ld" script. This file is for 512k flash (  
"rom(rx)   : org = 0x00000000, len = 512k"  ).
> Care must be taken if you write data to the flash - I'm not sure if the
> ethernut flashing routine supports multiple banks.
> If you don't use this feature there is no problem.
>   
This is the point! I use OpenOCD and the Turtelier2 JTAG. I use a self 
written tool ("TCPSend") to send command via localhost:4444 to OpenOCD.
My command will invoke the function "nut_flash" with one paremeter: my 
application "flash.bin".

Here is the codes snipped from "eri.cfg":

# Write image to flash.
#
proc nut_flash {IMGFILE {TYPE ""} {OFFSET ""}} {
    reset init
    flash protect 0 0 15 off
    set TYPE [nut_imgtype $IMGFILE $TYPE]
    set OFFSET [nut_imgtypeoffset $TYPE $OFFSET 0x100000]
    flash write_image erase $IMGFILE $OFFSET $TYPE
    verify_image $IMGFILE $OFFSET $TYPE
    at91sam7 gpnvm 2 set
}

I think the command "flash write_image erase...." can ony write on bank 
at once. No problem to add another "flash write_image erase..." command 
with a different offset for the second bank. But how can I split the 
*.bin file? Or, how I can say, write the first 256k into the first bank 
and the rest to the second bank?
Ther must be a common way to do this job! If I be despaired enough, I 
can write a rom file file splitter....

>   
>> It is possible to force some functions (module) into thump mode to save 
>> space? I have seen thump-interwork is enabled in NutOS. Is there 
>> something like __attribute__((thump)) for functions?
>>     
>
> Not that I know.
> I've declared many Makefiles for thumb in my own environment, which is
> based on 4.9.8.
> First I'd started with my application code and than with all possible
> Ethernut sourcefiles.
> Generally speaking it is mostly the interrupt routines left and the
> size difference was rather hughe.
> I'm able to run Nut/OS on SAM7S32 and SAM7S321 with this - although
> without IP on those.
> Speedwise it is also a win with SAM7S/X since the flash controller has
> waitstate-free prefetching for 16bit instructions only.
>
>   
Hello Bernd,

thank you for the fast answer! See my commend above.

I will dig into your diff file an try to setup a small applcation with 
modules in thump mode.

Greetings
André