Settings CFG_TUD_MEM_SECTION causes a section type conflict

[electretmike]

Operating System

Linux

Board

Custom STM32H7 based board

Firmware

class/net/ncm_device.c

What happened ?

When using CFG_TUD_MEM_SECTION I get a section conflict. This is because ntb_parameters is constant, while transmit_ntb isn't. See https://stackoverflow.com/questions/30076949/gcc-error-variable-causes-a-section-type-conflict

This could be fixed by adding two configuration values: CFG_TUD_RODATA_MEM_SECTION and CFG_TUD_BSS_MEM_SECTION and then replace all uses of CFG_TUD_MEM_SECTION with one of those two.

How to reproduce ?

#define CFG_TUSB_MEM_SECTION __attribute__ ((section(".usb_ram")))

compiler: arm-none-eabi-gcc (Fedora 13.2.0-5.fc40) 13.2.0

Debug Log as txt file (LOG/CFG_TUSB_DEBUG=2)

[build] Debug/_deps/tinyusb-src/src/class/net/ncm_device.c:140:73: error: 'ntb_parameters' causes a section type conflict with 'receive_ntb' [build] 140 | CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN tu_static const ntb_parameters_t ntb_parameters = { [build] | ^~~~~~~~~~~~~~ [build] Debug/_deps/tinyusb-src/src/class/net/ncm_device.c:157:58: note: 'receive_ntb' was declared here [build] 157 | CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN tu_static uint8_t receive_ntb[CFG_TUD_NCM_OUT_NTB_MAX_SIZE];

Screenshots

No response

I have checked existing issues, dicussion and documentation

• [X] I confirm I have checked existing issues, dicussion and documentation.

[electretmike]

Easier solution would be to remove CFG_TUD_MEM_SECTION from the const variables. Thay are not placed in RAM anyway

[HiFiPhile]

Hi, thank you for the issue, The correct fix would be add an interrupt EP buffer in CFG_TUD_MEM_SECTION, until now the only message sent is ntb_parameters but it could have other messages later.

CFG_TUD_MEM_SECTION is necessary as explained in tusb_config.h that some MCUs can only transfer to/from specific RAM region.

@rgrr

[rgrr]

Hmmm... @electretmike : which NCM are you using? The old one or the recent one? Recent one has my name in the copyright (Hardy Griech).

If you are at the current one: all this section stuff was already in the original NCM driver (without looking for excuses). Thought it would be wise to not touch that part.

How is CFG_TUD_MEM_SECTION defined for your part? Perhaps this definition is simply wrong?