1 ACCEPTED SOLUTION
Accepted Solutions
D-cache should not make things more difficult , so i recommend to not use it.
Just in Cube do not enable it, later can enable and do the cache management - was my idea, to make it more easy.
->
I forgot: you have to add this to the xxx_flash.ld file (just before the comment line : /*Remove... )
.RAM_SRD_sec : /* (NOLOAD) <- no initialize */
{
. = ALIGN(32);
*(.RAM_SRD_section)
. = ALIGN(32);
} >RAM_SRD
/* Remove information from the compiler libraries */And after mod the xxx_flash.ld file you see it is used ? ->
Now it should work. 8)
H7A3 has D-cache - how you manage this /with dma ? (see nothing in your text)
Simple solution: switch off (or not enable) D-cache . (NOW ! if bdma working...can work on this, cache management.)
If you have your data in ram, bdma cannot work:
Then to put your data array to a certain ram , write (example for my H7 :(
__attribute__((section(".RAM_SRD_section"))) int32_t playbuf[4096];
If the ram section to use is not in the linker script, you have to modify it, to have RAM_SRD , + give it a name.
For bdma only SRD area is useful:
Now look at your xxx_FLASH.ld file and edit...add new section, if not there (i have no H7A3 with this, so i cannot just give you one);
My H7A3 xx.ld file just has:
/* Memories definition */
MEMORY
{
DTCMRAM (xrw) : ORIGIN = 0x20000000, LENGTH = 128K
ITCMRAM (xrw) : ORIGIN = 0x00000000, LENGTH = 64K
RAM (xrw) : ORIGIN = 0x24000000, LENGTH = 1024K
FLASH (rx) : ORIGIN = 0x8000000, LENGTH = 2048K
}
-> modify -> add srd ram
/* Memories definition */
MEMORY
{
DTCMRAM (xrw) : ORIGIN = 0x20000000, LENGTH = 128K
ITCMRAM (xrw) : ORIGIN = 0x00000000, LENGTH = 64K
RAM (xrw) : ORIGIN = 0x24000000, LENGTH = 1024K
RAM_SRD (xrw) : ORIGIN = 0x38000000, LENGTH = 32K
FLASH (rx) : ORIGIN = 0x8000000, LENGTH = 2048K
}
ed.: I forgot:
you have to add this to the xxx_flash.ld file (just before the comment line : /*Remove... )
.RAM_SRD_sec : /* (NOLOAD) <- no initialize */
{
. = ALIGN(32);
*(.RAM_SRD_section)
. = ALIGN(32);
} >RAM_SRD
/* Remove information from the compiler libraries */
...maybe like this ... then try.
D-cache should not make things more difficult , so i recommend to not use it.
Just in Cube do not enable it, later can enable and do the cache management - was my idea, to make it more easy.
->
I forgot: you have to add this to the xxx_flash.ld file (just before the comment line : /*Remove... )
.RAM_SRD_sec : /* (NOLOAD) <- no initialize */
{
. = ALIGN(32);
*(.RAM_SRD_section)
. = ALIGN(32);
} >RAM_SRD
/* Remove information from the compiler libraries */And after mod the xxx_flash.ld file you see it is used ? ->
Now it should work. 8)
@AScha.3 First of all, thanks for the detailed help. I'm probably in over my head here and really appreciate your help. I still can't transmit using BDMA but I think I was able to get the SRD memory section enabled and put the data I want to TX there. VisualGDB provides a window to add external memory and it does a lot of the work for me but it does a lot more than you suggested which maybe a good thing or a bad thing. Here's how it modified the .lds file. VisualGDB set all the ALIGN(X) lines to ALIGN(4) so I changed them to ALIGN(32). I'm wondering if the .lds file works in bytes and not bits?
/* --- begin generated external memory sections -- */
.ram_srd_text :
{
. = ALIGN(32);
_sram_srd_text = .;
PROVIDE(__ram_srd_text_start = _sram_srd_text);
*(.ram_srd_text)
*(.ram_srd_text*)
. = ALIGN(32);
_eram_srd_text = .;
PROVIDE(__ram_srd_text_end = _eram_srd_text);
} > RAM_SRD AT >FLASH
_siram_srd_text = LOADADDR(.ram_srd_text);
.ram_srd_data :
{
. = ALIGN(32);
_sram_srd_data = .;
PROVIDE(__ram_srd_data_start = _sram_srd_data);
*(.ram_srd_data)
*(.ram_srd_data*)
. = ALIGN(32);
_eram_srd_data = .;
PROVIDE(__ram_srd_data_end = _eram_srd_data);
} > RAM_SRD AT >FLASH
_siram_srd_data = LOADADDR(.ram_srd_data);
.ram_srd_bss (NOLOAD) :
{
. = ALIGN(32);
_sram_srd_bss = .;
PROVIDE(__ram_srd_bss_start = _sram_srd_bss);
*(.ram_srd_bss)
*(.ram_srd_bss*)
. = ALIGN(32);
_eram_srd_bss = .;
PROVIDE(__ram_srd_bss_end = _eram_srd_bss);
} > RAM_SRD
/* --- end generated external memory sections -- */VisualGDB has a nice embedded memory explorer and here's what it shows.
Both DCache and ICache were already disabled in CubeMX so that probably wasn't my issue.
At this point I think the problem may be in my code that sets up the LPUART and BDMA and tries to transmit my message. So I'm going to triple check what's going on there.
Thanks again for all the help
