MCUXpresso IDE memory allocation question, Link error "region `SRAM_DTC' overflowed by xxxxbytes"

[Seongyon_Jeong]

Hi.

I am doing my job on board iMX RT1020EVK.

Just , I faced to  Link error  <<region `SRAM_DTC' overflowed by xxxxbytes>>   message  after  merging  example <<lwip_ip4_ip6_echo_freertos>>   on    example code <<freertos_flash_operation>>

after studying, I found  solution  from https://community.nxp.com/t5/i-MX-RT-Knowledge-Base/Reallocating-the-FlexRAM/ta-p/1117649,  https://community.nxp.com/t5/i-MX-Processors/106axf-section-bss-will-not-fit-in-region-SRAM-DTC-regi... 

anyway, I found  somethings strange on avoiding  problem by using SDRAM  as first RAM index  on example <<lwip_ip4_ip6_echo_freertos>>,

lwip example  does not  initialize SDRAM and has not routed pin map

It means  that  MCU does not recognize SDRAM,   no Enable , no clock.... Right ?? 

How can it be possible  using SDRAM   on run-time  in   lwip_ip4_ip6_echo_freertos sdk exam. ??

(that example does not include  driver. file.   fsl_semc.c) 

[jingpan · Accepted solution]

Hi @Seongyon_Jeong ,

BOOT ROM can initialize SDRAM by reading the data in DCD. You can compile the DCD data into application by define XIP_BOOT_HEADER_DCD_ENABLE=1

The DCD data is in dcd.c. If your SDRAM is different with RT1020-EVK, you should modify it according to your SDRAM.

Regards,

Jing