topic Re: in i.MX RT Crossover MCUs

Re:

john71 — Tue, 19 Oct 2021 08:10:15 GMT

I included in my project (for MIMXRT1160-EVK) emWin GUI.

I get this error:

MIMXRT1166_EVK_CM4.axf section `NonCacheable' will not fit in region `SRAM_DTC_cm4' MIMXRT1166_EVK_CM4 C/C++ Problem
region `SRAM_DTC_cm4' overflowed by 7299032 bytes MIMXRT1166_EVK_CM4 C/C++ Problem

when I look at the code I see

#define APP_IMG_HEIGHT 1280 #define APP_IMG_WIDTH 720 AT_NONCACHEABLE_SECTION_ALIGN(static uint32_t s_frameBuffer[2][APP_IMG_HEIGHT][APP_IMG_WIDTH], FRAME_BUFFER_ALIGN);

It's a huge amount of memory and can not fit into existent region.

What do I miss?

Actually it tries to put the buffer in

__attribute__((section("NonCacheable,\"aw\",%nobits @"))) static uint32_t s_frameBuffer[2][1280][720] __attribute__((aligned(64)))

And it's quite big

Memory region Used Size Region Size %age Used
NCACHE_REGION: 0 GB 16 MB 0.00%

Why the compiler refers to SRAM_DTC_cm4 section?

Re: A region overflow problem.

john71 — Tue, 19 Oct 2021 06:43:52 GMT

So, the final question is - why I can not allocate the data in the section?

__attribute__((section("NonCacheable,\"aw\",%nobits @"))) static uint32_t s_frameBuffer[2][1280][720] __attribute__((aligned(64)))

Why I get

Well...I looked at the example project. The generated linker file looks like

/* BSS section for NCACHE_REGION */
.bss_RAM2 : ALIGN(4)
{
PROVIDE(__start_bss_RAM2 = .) ;
PROVIDE(__start_bss_NCACHE_REGION = .) ;
*(NonCacheable)
*(.bss.$RAM2)
*(.bss.$NCACHE_REGION)
*(.bss.$RAM2.*)
*(.bss.$NCACHE_REGION.*)
. = ALIGN (. != 0 ? 4 : 1) ; /* avoid empty segment */
PROVIDE(__end_bss_RAM2 = .) ;
PROVIDE(__end_bss_NCACHE_REGION = .) ;
} > NCACHE_REGION AT> NCACHE_REGION

My one

/* BSS section for SRAM_ITC_cm4 */
.bss_RAM2 : ALIGN(4)
{
PROVIDE(__start_bss_RAM2 = .) ;
PROVIDE(__start_bss_SRAM_ITC_cm4 = .) ;
*(.bss.$RAM2)
*(.bss.$SRAM_ITC_cm4)
*(.bss.$RAM2.*)
*(.bss.$SRAM_ITC_cm4.*)
. = ALIGN (. != 0 ? 4 : 1) ; /* avoid empty segment */
PROVIDE(__end_bss_RAM2 = .) ;
PROVIDE(__end_bss_SRAM_ITC_cm4 = .) ;
} > SRAM_ITC_cm4 AT> SRAM_ITC_cm4

Where in the code I tie NonCacheable to NCACHE_REGION ?

Re: A region overflow problem.

john71 — Tue, 19 Oct 2021 07:39:34 GMT

OK. I found it. It should be defined at Settings->MCU Linker->Managed Linker Script