Memory partitioning on stm32h747i

[TayyabaZainab0807]

I am new to the zephyr and west. I am trying to program my stm32h747i_disco device.
I use: west build -p always -b stm32h747i_disco_m7 zephyr/samples/basic/hello_world/
but it give me following partitioning:

       FLASH:      126480 B         1 MB     12.06%
         RAM:      434624 B       512 KB     82.90%
        QSPI:          0 GB       256 MB      0.00%
       SRAM1:          0 GB       128 KB      0.00%
       SRAM2:          0 GB       128 KB      0.00%
       SRAM3:         16 KB        32 KB     50.00%
       SRAM4:          0 GB        64 KB      0.00%
      SDRAM2:          0 GB        32 MB      0.00%
    IDT_LIST:          0 GB         2 KB      0.00%

Although stm32h747i_disco has 2MB flash and 1MB RAM, I don't want this partitioning between two core as I am only using one m7.
I am wondering what needs to be done to get 2 MB flash and 1MB ram on core m7?

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[FRASTM]

Hi @TayyabaZainab0807

• For the RAM, you have access to the 864K. Did you try to add the node for partitionning the TCM RAM (dedicated to the cortex M7) ?

• For the Flash, did you try to redefine the flash

		flash-controller@52002000 {
			flash0: flash@8000000 {
				reg = <0x08000000 DT_SIZE_K(2048)>;
			};
		};

[TayyabaZainab0807]

I got the new device and only ran the blinky code on there but was getting this partitioning. For my actual project, I want to access all the ram and flash on m7.
so far I tried to change the ram and flash in this file: boards/arm/stm32h747i_disco/stm32h747i_disco_m7.yaml
but that didn't work.

Can you please guide me how to access 864k ram and 2MB flash..That files do I have to change and that code I have to run.

[jhedberg]

@erwango @FRASTM seems like this should be converted into a discussion, since it seems more of a question rather than a bug?

[FRASTM]

In the DTS of your board :

• try to change the node for the flash, with something like :

diff --git a/boards/arm/stm32h747i_disco/stm32h747i_disco_m7.dts b/boards/arm/stm32h747i_disco/stm32h747i_disco_m7.dts
index 6104a7c176..6423bdfdeb 100644
--- a/boards/arm/stm32h747i_disco/stm32h747i_disco_m7.dts
+++ b/boards/arm/stm32h747i_disco/stm32h747i_disco_m7.dts
@@ -9,7 +9,14 @@
 #include <st/h7/stm32h747xihx-pinctrl.dtsi>
 #include "stm32h747i_disco.dtsi"
 
+/delete-node/ &flash0;
+
 / {
+		flash0: flash@8000000 {
+				reg = <0x08000000 DT_SIZE_K(2048)>;
+		};
+
+
 	model = "STMicroelectronics STM32H747I DISCOVERY board";
 	compatible = "st,stm32h747i-disco";

• the stm32h747i_disco_m7 already has acccess to the whole RAM

Building a samples/hello_world gives:

Memory region         Used Size  Region Size  %age Used
           FLASH:       16474 B         2 MB      0.79%
             RAM:        4416 B       512 KB      0.84%
            QSPI:          0 GB       256 MB      0.00%
           SRAM1:          0 GB       128 KB      0.00%
           SRAM2:          0 GB       128 KB      0.00%
           SRAM3:         16 KB        32 KB     50.00%
           SRAM4:          0 GB        64 KB      0.00%
          SDRAM2:          0 GB        32 MB      0.00%
        IDT_LIST:          0 GB         2 KB      0.00%

[peinal]

I have the exact same problem @TayyabaZainab0807 had/has. What file(s) to modify and how to modify them to place data in the RAM sections showing 0% utilized? My table shows 256MB EXTRAM, SRAM1-SRAM4, and SDRAM2. I can place a given buffer in SRAM1 utilizing the__attribute__ directive andsee the buffer is placedin SRAM1, but then I also get a bss overflow error during the build. How exactly do I place a buffer in RAM section XYZ AND tell the linker/compiler not to place the buffer in bss?

[FRASTM]

With a west debug, the memory examination should be possible at any flash address in bank1 and in bank2, at any memory address in any RAM block too

[TayyabaZainab0807]

I was able to access 2MB of flash by replacing:

&flash0 {
	partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		/* Set 2KB of storage at the end of first 1MB flash */
		storage_partition: partition@ff800 {
			label = "storage";
			reg = <0x000ff800 DT_SIZE_K(2)>;
		};
	};
};

with

&flash0 {
	reg = <0x08000000 DT_SIZE_K(2048)>;
};

But I am unable to access RAM more then 512 KB

Memory region         Used Size  Region Size  %age Used
           FLASH:      327028 B         2 MB     15.59%
             RAM:      523456 B       512 KB     99.84%
            QSPI:          0 GB       256 MB      0.00%
           SRAM1:          0 GB       128 KB      0.00%
           SRAM2:          0 GB       128 KB      0.00%
           SRAM3:         16 KB        32 KB     50.00%
           SRAM4:          0 GB        64 KB      0.00%
          SDRAM2:          0 GB        32 MB      0.00%
        IDT_LIST:          0 GB         2 KB      0.00%

[FRASTM]

Building the samples/hello_word for the stm32h747i_disco_m7 target, the SRAMx is accessible:
sram0: memory@24000000
sram1: memory@30000000
sram3: memory@30040000
sram4: memory@38000000