Hello!
I'm working on a In Application Programming solution for an STR711
Microcontroller. There are some reasons for me, to execute the routines,
which will write the flash banks from RAM.
So here is my question:
I compiled this routines for executing them in RAM.
I reserved some space for this code by defining a new memory range in
the linker script ( .ld )
MEMORY
{
IntCodeRAM (rx) : ORIGIN = 0x00000000, LENGTH = 256k
ReservedRAM (rw) : ORIGIN = 0x20000000, LENGTH = 2k
IntDataRAM (rw) : ORIGIN = 0x20000200, LENGTH = 62k
}
It works, but does someone knows a more flexible method?
The main Problem is, i think, to find an empty space in RAM.
Thanks, Stefan
Guest
#1173312
> IntCodeRAM (rx) : ORIGIN = 0x00000000, LENGTH = 256k > ReservedRAM (rw) : ORIGIN = 0x20000000, LENGTH = 2k > IntDataRAM (rw) : ORIGIN = 0x20000200, LENGTH = 62k 0x200 is 512, not 2048 (2K).
A.K. wrote: >> IntCodeRAM (rx) : ORIGIN = 0x00000000, LENGTH = 256k >> ReservedRAM (rw) : ORIGIN = 0x20000000, LENGTH = 2k >> IntDataRAM (rw) : ORIGIN = 0x20000200, LENGTH = 62k > > 0x200 is 512, not 2048 (2K). Thanks, just a little typing error. But this isn't the Problem. Regards, Stefan
Guest
#1173314
To permanently place some functions in RAM, you do not have to define a separate memory region. The linker script can place them the into the same RAM memory region as the data.
Guest
#1173315
As already mentioned by A.K. an extra entry in "MEMORY" is not needed.
You could simple try use this function attribute:
_attribute_ ((long_call, section (".data")))
This will assign the function declared with the attribute to the
".data". No modification in the linker-script should be needed for this.
An addtional section (i.e. ".fastrun") might be useful later since the
locations of such extra sections can be changed easily in the
linker-script without side-effect on the "real" .data.
May serve as examples:
http://www.siwawi.arubi.uni-kl.de/avr_projects/arm_projects/index.html#gcc_ramfunc
http://www.siwawi.arubi.uni-kl.de/avr_projects/arm_projects/index_at91.html#at91_gamma
both not for STR711 but the method is not target-dependent
Martin Thomas
Martin Thomas wrote: > As already mentioned by A.K. an extra entry in "MEMORY" is not needed. > > You could simple try use this function attribute: > _attribute_ ((long_call, section (".data"))) > This will assign the function declared with the attribute to the > ".data". No modification in the linker-script should be needed for this. > > An addtional section (i.e. ".fastrun") might be useful later since the > locations of such extra sections can be changed easily in the > linker-script without side-effect on the "real" .data. > > May serve as examples: > http://www.siwawi.arubi.uni-kl.de/avr_projects/arm_projects/index.html#gcc_ramfunc > http://www.siwawi.arubi.uni-kl.de/avr_projects/arm_projects/index_at91.html#at91_gamma > both not for STR711 but the method is not target-dependent > > Martin Thomas Hello! At first, thanks for all your help. I read and tried the examples above. The Problem is, that i don't want to place the code permamently in RAM. I don't want to wast 3kB of RAM, if I don't need the functions. Sorry guys, im very new to programming ARM. Regards, Stefan
Guest
#1173317
If you have several functions to execute in RAM, but need only one at a time placed there, look for the "Overlay" command in the GNU LD documentation: http://www.gnu.org/software/binutils/manual/ld-2.9.1/html_chapter/ld_3.html
Guest
#1173318
Martin Thomas wrote: > As already mentioned by A.K. an extra entry in "MEMORY" is not needed. > > You could simple try use this function attribute: > _attribute_ ((long_call, section (".data"))) > This will assign the function declared with the attribute to the > ".data". No modification in the linker-script should be needed for this. > > An addtional section (i.e. ".fastrun") might be useful later since the > locations of such extra sections can be changed easily in the > linker-script without side-effect on the "real" .data. > > May serve as examples: > http://www.siwawi.arubi.uni-kl.de/avr_projects/arm_projects/index.html#gcc_ramfunc > http://www.siwawi.arubi.uni-kl.de/avr_projects/arm_projects/index_at91.html#at91_gamma > both not for STR711 but the method is not target-dependent > > Martin Thomas Dear Martin, I have a quiestion about the function attribute, i want to write some bytes to flash. My function is located in RAM, this works only with functions without function arguments. Suppose you have a flash write function with address and data arguments. Can we pass this arguments as well. Regards, Bram Dobbelaar #define FASTRUN _attribute_ ((long_call, section (".data"))) FASTRUN void Erase_sector1(void); FASTRUN void Word_program(void); FASTRUN void FLASH_WWrite(u32 XtargetAdd, u32 Xdata); u32 Addres,data;
Bram Dobbelaar wrote: > I have a quiestion about the function attribute, i want to write some > bytes to flash. My function is located in RAM, this works only with > functions without function arguments. Suppose you have a flash write > function with address and data arguments. Can we pass this arguments as > well. I have not noticed this before. Can you step though the code with a debugger to see what is going on?
Guest
#1173320
Martin Thomas wrote: > Bram Dobbelaar wrote: >> I have a quiestion about the function attribute, i want to write some >> bytes to flash. My function is located in RAM, this works only with >> functions without function arguments. Suppose you have a flash write >> function with address and data arguments. Can we pass this arguments as >> well. > > I have not noticed this before. Can you step though the code with a > debugger to see what is going on? Thanks for you're answer. I have an another probably related problem. I can erase flash and write word in flash memory (i use the attribute as mentioned ). It only works one time after programming the flash. After a power down and up the copied function in RAM are not working. Do i need to change the linker script to be sure the ram functions are loaded in memory. I want to make a flash table that can be changed (error correction for a sensor application). Probably i will do this in eeprom, but my eeprom was to small, so i thought maybe a table in flash is possible. Regards, Bram Dobbelaar