memory - STM32 Editing Linker Script - Stack Overflow

admin管理员组

文章数量:1332873

In the stm32f767zi reference manual the memory anization is divvied into: FLASH, SRAM1, SRAM2, ITCM and DTCM but in the linker script the project is either stored into FLASH or RAM. I want to edit the linker script so I can store data in a specific memory region.

I am trying to change it from:

MEMORY
{
    RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 512K
    FLASH (rx) : ORIGIN = 0x8000000, LENGTH = 2048K
}

To this:

MEMORY
{
    ITCMRAM (xrw) : ORIGIN = 0x00000000, LENGTH = 16K
    DTCMRAM (xrw) : ORIGIN = 0x20000000, LENGTH = 128K
    RAM (xrw) : ORIGIN = 0x20020000, LENGTH = 368K
    SRAM (xrw) : ORIGIN = 0x2007C000, LENGTH = 16K
    FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 2048K
}

So I added in the sections this:

_sisram = LOADADDR(.sram);
.sram :
{
    . = ALIGN(4);
    _ssram = .; /* create a global symbol at data start */
    (.sram) / .data sections */
    (.sram) /* .data* sections */
    . = ALIGN(4);
    _esram = .; /* define a global symbol at data end */
} >SRAM AT> FLASH
_siitcm = LOADADDR(.itcm);
.itcm :
    . = ALIGN(4);
    _sitcm = .; /* create a global symbol at data start */
    (.itcm) / .data sections */
    (.itcm) /* .data* sections */
    . = ALIGN(4);
    _eitcm = .; /* define a global symbol at data end */
} >ITCMRAM AT> FLASH
_sidtcm = LOADADDR(.data);
.dtcm :
{
    . = ALIGN(4);
    _sdtcm = .; /* create a global symbol at data start */
    (.dtcm) / .data sections */
    (.dtcm) /* .data* sections */
    . = ALIGN(4);
    _edtcm = .; /* define a global symbol at data end */
} >DTCMRAM AT> FLASH

and then moved to the startup file

first I added the following:

.word _sisram
.word _ssram
.word _esram
.word _siitcm
.word _sitcm
.word _eitcm
.word _sidtcm
.word _sdtcm
.word _edtcm

and then the copy loop like this:

//SRAM
ldr r0, =_ssram
ldr r1, =_esram
ldr r2, =_sisram
movs r3, #0
b LoopCopySramInit

CopySramInit:
ldr r4, [r2, r3]
str r4, [r0, r3]
adds r3, r3, #4

LoopCopySramInit:
adds r4, r0, r3
cmp r4, r1
bcc CopySramInit
//ITCM
ldr r0, =_sitcm
ldr r1, =_eitcm
ldr r2, =_siitcm
movs r3, #0
b LoopCopyItcmInit

CopyItcmInit:
ldr r4, [r2, r3]
str r4, [r0, r3]
adds r3, r3, #4

LoopCopyItcmInit:
adds r4, r0, r3
cmp r4, r1
bcc CopyItcmInit
//DTCM
ldr r0, =_sdtcm
ldr r1, =_edtcm
ldr r2, =_sidtcm
movs r3, #0
b LoopCopyDtcmInit

CopyDtcmInit:
ldr r4, [r2, r3]
str r4, [r0, r3]
adds r3, r3, #4

LoopCopyDtcmInit:
adds r4, r0, r3
cmp r4, r1
bcc CopyDtcmInit

So I am basically copying what the mx did to the data section from flash to RAM, but when I run I get this error undefined reference to `_ssram' I tried to change it from .word to .extern but still the same error.

what am I missing ? is there a better way to divided the RAM region to ITCM DTCM and RAM ? Thank you for your time.

本文标签： memorySTM32 Editing Linker ScriptStack Overflow