S32KのトピックRe: How to complie Flash driver to RAM? while other source program still in flash?

How to complie Flash driver to RAM? while other source program still in flash?

459021854 — Thu, 24 Sep 2020 08:43:39 GMT

Hi, experts:

please do me a favor, when I develop a bootloader. I need separate Flash driver with the other parts of bootloader code to different places.

Flash driver, such as FLASH_DRV_Program, should be compiled as a separate .src file and be placed at RAM.

other parts of bootloader code should be placed in the flash.

I have tryed __attribute__((section (".customSection")))

status_t __attribute__((section (".customSection"))) FLASH_DRV_Program(const flash_ssd_config_t * pSSDConfig,
uint32_t dest,
uint32_t size,
const uint8_t * pData)

but in .map the result turn out to be

this means function FLASH_DRV_Program is loaded from address 0x00007acc to address 0x20000000, NOT I want.

I just want FLASH_DRV_Program is directly placed in RAM by compiler, NOT loaded from flash.

If the flash driver which placed in RAM be compiler as a separate .src, that's better.

How can I solve those problem? please help me, much appreciated. my MCU is S32K144.

@all experts

Re: How to complie Flash driver to RAM? while other source program still in flash?

kef2 — Thu, 24 Sep 2020 09:09:16 GMT

Hi,

I'm not expert of GCC linker scripts, but as I understand it ": AT(xx)" in linker file instructs section to be loaded from xx.

.code : AT(__CODE_ROM)
{
    . = ALIGN(4);
    __CODE_RAM = .;
    __code_start__ = .;      /* Create a global symbol at code start. */
    *(.code_ram)             /* Custom section for storing code in RAM */
    . = ALIGN(4);
    __code_end__ = .;        /* Define a global symbol at code end. */
} > m_data

__CODE_ROM is a location in flash while m_data is RAM. So try removing : AT(xx) and see.

Regards,

Edward

Re: How to complie Flash driver to RAM? while other source program still in flash?

459021854 — Thu, 24 Sep 2020 09:50:27 GMT

Hi, Edward

I have tryed your method that's not working.

I think because in c file " startup.c " there is code to copy code from FLASH to RAM,

that's not I wanted. I do not want any COPY happened, because i do not want a copy of flash driver be placed in flash. just want only one flash driver directly be placed in RAM.

PLEASE, still need help.

Re: How to complie Flash driver to RAM? while other source program still in flash?

Alexis_A — Fri, 25 Sep 2020 17:31:42 GMT

Hello @459021854 ,

Please check the following post, explains how to modify the linker file to add the code allocation regions.

Best Regards,

Alexis Andalon