How to use STM32CubeIDE or STM32CubeMX to automatically add settings for RAM_D2 and RAM_D3 in LD fil

[RajeevAroraCrcEvans]

Hi All,

Requesting help with below.

I am using latest version of STM32CubeIDE. The microcontroller in use is STM32H743BITx.

I have concerns with regards to:
1. Whether to add ALIGN(4) even inside the FLASH sections present in STM32H753BITX_FLASH.ld (attached)

2. The file generated by STM32CubeMX (ran from within STM32CubeIDE) generated a STM32H753BITX_FLASH.ld file in the project folder. It does not contain sections that reside in RAM_D2 and RAM_D3. Attached the STM32H753BITX_FLASH.ld.txt file for reference. Is there a way available with STM32CubeMX (preferably) or with STM32CubeIDE to add the necessary RAM sections in the LD file for STM32H743BITx?

3. I observe that macro DATA_IN_D2_SRAM is disabled and hence concerned about how clocks to RAM_D1, RAM_D2 and RAM_D3 are being enabled. I am also unable to figure out any valid assignment to register AHB2ENR which would enable the clock to the three RAM sections.

In file system_stm32h7xx.c please refer to below section starting at line number 79.

The macro DATA_IN_D2_SRAM is disabled

/************************* Miscellaneous Configuration ************************/

/*!< Uncomment the following line if you need to use initialized data in D2 domain SRAM (AHB SRAM) */

/* #define DATA_IN_D2_SRAM */

Then from line number 267

#if defined(DATA_IN_D2_SRAM)

/* in case of initialized data in D2 SRAM (AHB SRAM), enable the D2 SRAM clock (AHB SRAM clock) */

#if defined(RCC_AHB2ENR_D2SRAM3EN)

RCC->AHB2ENR |= (RCC_AHB2ENR_D2SRAM1EN | RCC_AHB2ENR_D2SRAM2EN | RCC_AHB2ENR_D2SRAM3EN);

#elif defined(RCC_AHB2ENR_D2SRAM2EN)

RCC->AHB2ENR |= (RCC_AHB2ENR_D2SRAM1EN | RCC_AHB2ENR_D2SRAM2EN);

#else

RCC->AHB2ENR |= (RCC_AHB2ENR_AHBSRAM1EN | RCC_AHB2ENR_AHBSRAM2EN);

#endif /* RCC_AHB2ENR_D2SRAM3EN */

 

tmpreg = RCC->AHB2ENR;

(void) tmpreg;

#endif /* DATA_IN_D2_SRAM */

 

Please help resolve my above concerns.

Thanks!

Rajeev

[TDK]

CubeMX only provides those premade linker scripts. If you want something different, you need to edit the file yourself and add/change the sections.

 

[AScha.3]

Hi,

1 > Whether to add ALIGN(4) even inside the FLASH sections present ..

yes, in all sections.

2 > .. as TDK told : you have to set, what you want.

 

3> I dont know , what you ask about, i just set the sections as i want and it works. (on H743 )

[RajeevAroraCrcEvans]

Hi  @Khouloud ZEMMELI , @AScha.3

Since answer to my first query is Yes, I believe the default STM32H753BITX_FLASH.ld file provided/added by ST should be updated to include the ALIGN(4) in all sections (especially in the FLASH sections). I would request ST / Khouloud (and her team) to update STM32CubeIDE so that the updated file is available when user generates the code.

 

@AScha.3I would like to understand from you about whether any of your firmware uses the RAM which is being refereed to as RAM_D2, and RAM_D3

Below is what could be added to MEMORY section:
RAM_D1 (xrw) : ORIGIN = 0x24000000, LENGTH = 512K /* AXI SRAM section */
RAM_D2 (xrw) : ORIGIN = 0x30000000, LENGTH = 288K  /* SRAM 1 + SRAM 2 + SRAM 3 */
RAM_D3 (xrw) : ORIGIN = 0x38000000, LENGTH = 64K /* SRAM 4 */

Later similar to how various RAM sections are defined (with the closing brackets being followed by ">RAM_D1" (but without quotes)) what sections do I declare using RAM_D2 and RAM_D3. And how do I ensure that RAM_D3 gets filled before RAM_D2, and RAM_D2 gets filled before RAM_D1.

In SCT file (linker file) which was used by Keil IDE we used the keyword .ANY followed by a number (The higher the number, the higher the priority of the section being used by variables).

 

Please share your inputs.

Regards,

Rajeev

 

[TDK]

> I believe the default STM32H753BITX_FLASH.ld file provided/added by ST should be updated to include the ALIGN(4) in all sections (especially in the FLASH sections).

The linker script already has alignment to 32-bit words.

> And how do I ensure that RAM_D3 gets filled before RAM_D2, and RAM_D2 gets filled before RAM_D1.

Assignments to a particular section must be done explicitly. The linker can not split them up based on available space. To specify a section, use the attribute in the variable definition. Here is a link for how to do that:

https://community.st.com/t5/stm32cubeide-mcus/stm32cubeide-doesn-not-support-declaring-variable-in-dtcm-on/m-p/122520/highlight/true#M4385

 

 

[RajeevAroraCrcEvans]

Thanks @TDK  for a quick response.

I observe below when comparing the file that my team uses (on left) and the one that STM32CubeMX generated (on the right):

Regards,

Rajeev

[RajeevAroraCrcEvans]

Hi @TDK 

From your second input I understand that while declaring any variable, I'll have to ensure that it is preceded with the __attribute__ and the section() keywords, along with the section name.

Below is part of my SCT file that I use with Keil compiler. If I want to create a LD file with similar data, then this is not possible, as there is no keyword with LD file which equals/is-similar to the the ANY keyword being used.

Is my above understanding correct?

;**** PART OF SCT FILE START *****
RW_RAM1 0x30000000 0x00020000 { ; RW data
.ANY (+RW +ZI)
}
RW_RAM2 0x30020000 0x00020000 {
.ANY (+RW +ZI)
}
RW_RAM3 0x30040000 0x00008000 { ; should be used for creating buffers for ETHERNET and USB
.ANY (+RW +ZI)
}
RW_IRAM1 0x20000000 0x00020000 { ; RW data
.ANY99 (+RW +ZI)
}
RW_IRAM2 0x24000000 0x00060000 { ; Reduced size by amount of space needed for ARM_LIB_STACK and ARM_LIB_HEAP. Example change size to 0x00060000 if both sections are needed.
.ANY98 (+RW +ZI)
}
; StackRAM( ( ImageLimit( RW_IRAM2 ) + 0x07 ) AND ~0x07 )
; {
; *(STACK).ANY99 (+RW +ZI)
; }
ARM_LIB_STACK 0x24070000 EMPTY -0x10000 { ; Stack region growing down, hence start address is 0x24060000
}
ARM_LIB_HEAP 0x24070000 EMPTY 0x10000 { ; Heap region growing up
}

;**** PART OF SCT FILE END *****

 

Please share your views.

Thanks!

Rajeev

[TDK]

Your understanding is correct. You can do this in the Keil linker, but you cannot do this in the STM32CubeIDE linker. There is not an equivalent keyword to ANY there. All you can do is specify them individually.

[Tesla DeLorean]

https://community.st.com/t5/stm32-mcus-products/my-stm32h743vi-application-runs-to-a-debug-instruction-in-the/m-p/254664

 

; Reset handler
Reset_Handler PROC
 EXPORT Reset_Handler [WEAK]
 IMPORT SystemInit
 IMPORT __main
 
 LDR R0, =0x580244DC ; Enable D2SRAM clocks in RCC_AHB2ENR
 LDR R1, [R0]
 ORR R1, #0xE0000000
 STR R1, [R0]
 
 LDR R0, =SystemInit
 BLX R0
 LDR R0, =__main
 BX R0
 
 ENDP ; Reset_Handler

[Tesla DeLorean]

https://community.st.com/t5/stm32-mcus-products/how-to-properly-enable-all-rams-on-a-single-core-stm32h7/m-p/309049

https://community.st.com/t5/stm32-mcus-products/want-to-store-data-in-sram-d2-domain-what-is-missing-to-avoid/m-p/342349

 

[RajeevAroraCrcEvans]

Hi @TDK , @AScha.3 ,

I forgot to talk about my observation with system_stm32h7xx.c and macro DATA_IN_D2_SRAM

My understanding is that in order to use the any of the various available RAMs, the clock to the RAM that need to be sued should be enabled.

I believe to enable RAM_D1, RAM_D2 and RAM_D3 the following line of code should get executed:
RCC->AHB2ENR |= (RCC_AHB2ENR_D2SRAM1EN | RCC_AHB2ENR_D2SRAM2EN | RCC_AHB2ENR_D2SRAM3EN);

 

However with DATA_IN_D2_SRAM undefined I am unaware of which piece of code (generated by STM32CubeIDE) is enabling the three RAM sections.

Regards,

Rajeev

[AScha.3]

Hi @RajeevAroraCrcEvans ,

maybe i understand your "problem" : is ram clk enabled - or not ?

Just from my H743 program, in  system_stm32h7xx.c :

 RCC->AHB2ENR |= (RCC_AHB2ENR_D2SRAM1EN | RCC_AHB2ENR_D2SRAM2EN | RCC_AHB2ENR_D2SRAM3EN);

 All ram areas enabled , default.

So dont worry about...

I use ITC for stack and heap, D2 for circular DMA (always running), D1 for all other:

 

[RajeevAroraCrcEvans]

Hi @AScha.3 
Thanks for sharing the inputs.
I am novice to STM32CubeIDE environment. Until now I've been using the Keil compiler.

Concern: Before I send the HEX (for testing) I want to ensure that all the used RAM sections are receiving clock.

I need to code for a new board/PCB-with-microcontroller that is currently not available with me. I can only send the generated HEX file to one of my teammates in a different country (for occasional) testing.

I tried looking in the ELF file, and I only observe below. I even tried searching with RAM_D1 but the search did not produce any result. Am I missing something in settings due to which I do not observe information similar to the snippet that you have shared?

Below is the snippet from the system_stm32h7xx.c file. The code part has a greyed background which means that the code part is disabled.

This means that even line number 270 is disabled (which is the code line that you have shared in your response).

Now if I try finding the macro (DATA_IN_D2_SRAM) used on line number 267 the macro is commented out.

Thus I am unable to understand which part of code (generated by STM32CubeMX and being compiled using STM32CubeIDE) is enabling the clocks to the RAM_D2 and RAM_D3 sections.

Also, my code currently does not call below macro. Does your code call the below macro in main() or some place else?

 

[RajeevAroraCrcEvans]

Answer received for my first question:
https://community.st.com/t5/stm32cubemx-mcus/stm32cubeide-generated-xxx-flash-ld-file-does-not-include-align/m-p/639839#M27216