I am trying to build an STM32 application with my own CMake file. I have been able to compile and link a static library with a project and build the executable. I am using this .ld file:
/* Entry Point */
ENTRY(Reset_Handler)
/* Highest address of the user mode stack */
_estack = ORIGIN(RAM_D1) + LENGTH(RAM_D1); /* end of RAM */
/* Generate a link error if heap and stack don't fit into RAM */
_Min_Heap_Size = 0x200 ; /* required amount of heap */
_Min_Stack_Size = 0x400 ; /* required amount of stack */
/* Specify the memory areas */
MEMORY
{
ITCMRAM (xrw) : ORIGIN = 0x00000000, LENGTH = 64K
DTCMRAM (xrw) : ORIGIN = 0x20000000, LENGTH = 128K
FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 1024K
RAM_D1 (xrw) : ORIGIN = 0x24000000, LENGTH = 320K
RAM_D2 (xrw) : ORIGIN = 0x30000000, LENGTH = 32K
RAM_D3 (xrw) : ORIGIN = 0x38000000, LENGTH = 16K
}
/* Define output sections */
SECTIONS
{
/* The startup code goes first into FLASH */
.isr_vector :
{
. = ALIGN(4);
KEEP(*(.isr_vector)) /* Startup code */
. = ALIGN(4);
} >FLASH
/* The program code and other data goes into FLASH */
.text :
{
. = ALIGN(4);
*(.text) /* .text sections (code) */
*(.text*) /* .text* sections (code) */
*(.glue_7) /* glue arm to thumb code */
*(.glue_7t) /* glue thumb to arm code */
*(.eh_frame)
KEEP (*(.init))
KEEP (*(.fini))
. = ALIGN(4);
_etext = .; /* define a global symbols at end of code */
} >FLASH
/* Constant data goes into FLASH */
.rodata :
{
. = ALIGN(4);
*(.rodata) /* .rodata sections (constants, strings, etc.) */
*(.rodata*) /* .rodata* sections (constants, strings, etc.) */
. = ALIGN(4);
} >FLASH
.ARM.extab : { *(.ARM.extab* .gnu.linkonce.armextab.*) } >FLASH
.ARM : {
__exidx_start = .;
*(.ARM.exidx*)
__exidx_end = .;
} >FLASH
.preinit_array :
{
PROVIDE_HIDDEN (__preinit_array_start = .);
KEEP (*(.preinit_array*))
PROVIDE_HIDDEN (__preinit_array_end = .);
} >FLASH
.init_array :
{
PROVIDE_HIDDEN (__init_array_start = .);
KEEP (*(SORT(.init_array.*)))
KEEP (*(.init_array*))
PROVIDE_HIDDEN (__init_array_end = .);
} >FLASH
.fini_array :
{
PROVIDE_HIDDEN (__fini_array_start = .);
KEEP (*(SORT(.fini_array.*)))
KEEP (*(.fini_array*))
PROVIDE_HIDDEN (__fini_array_end = .);
} >FLASH
/* used by the startup to initialize data */
_sidata = LOADADDR(.data);
/* Initialized data sections goes into RAM, load LMA copy after code */
.data :
{
. = ALIGN(4);
_sdata = .; /* create a global symbol at data start */
*(.data) /* .data sections */
*(.data*) /* .data* sections */
*(.RamFunc) /* .RamFunc sections */
*(.RamFunc*) /* .RamFunc* sections */
. = ALIGN(4);
_edata = .; /* define a global symbol at data end */
} >RAM_D1 AT> FLASH
/* Uninitialized data section */
. = ALIGN(4);
.bss :
{
/* This is used by the startup in order to initialize the .bss section */
_sbss = .; /* define a global symbol at bss start */
__bss_start__ = _sbss;
*(.bss)
*(.bss*)
*(COMMON)
. = ALIGN(4);
_ebss = .; /* define a global symbol at bss end */
__bss_end__ = _ebss;
} >RAM_D1
/* User_heap_stack section, used to check that there is enough RAM left */
._user_heap_stack :
{
. = ALIGN(8);
PROVIDE ( end = . );
PROVIDE ( _end = . );
. = . + _Min_Heap_Size;
. = . + _Min_Stack_Size;
. = ALIGN(8);
} >RAM_D1
.lwip_sec (NOLOAD) :
{
. = ABSOLUTE(0x30000000);
*(.RxDecripSection)
. = ABSOLUTE(0x30000060);
*(.TxDecripSection)
. = ABSOLUTE(0x30000200);
*(.Rx_PoolSection)
} >RAM_D2
/* Remove information from the standard libraries */
/DISCARD/ :
{
libc.a ( * )
libm.a ( * )
libgcc.a ( * )
}
.ARM.attributes 0 : { *(.ARM.attributes) }
}
I define some variables like the Reset_Handler entry point in this file:
.syntax unified
.cpu cortex-m7
.fpu softvfp
.thumb
.global g_pfnVectors
.global Default_Handler
/* start address for the initialization values of the .data section.
defined in linker script */
.word _sidata
/* start address for the .data section. defined in linker script */
.word _sdata
/* end address for the .data section. defined in linker script */
.word _edata
/* start address for the .bss section. defined in linker script */
.word _sbss
/* end address for the .bss section. defined in linker script */
.word _ebss
/* stack used for SystemInit_ExtMemCtl; always internal RAM used */
.section .text.Reset_Handler
.weak Reset_Handler
.type Reset_Handler, %function
Reset_Handler:
ldr sp, =_estack /* set stack pointer */
/* Call the clock system initialization function.*/
bl SystemInit
/* Copy the data segment initializers from flash to SRAM */
ldr r0, =_sdata
ldr r1, =_edata
ldr r2, =_sidata
movs r3, #0
b LoopCopyDataInit
CopyDataInit:
ldr r4, [r2, r3]
str r4, [r0, r3]
adds r3, r3, #4
LoopCopyDataInit:
adds r4, r0, r3
cmp r4, r1
bcc CopyDataInit
/* Zero fill the bss segment. */
ldr r2, =_sbss
ldr r4, =_ebss
movs r3, #0
b LoopFillZerobss
FillZerobss:
str r3, [r2]
adds r2, r2, #4
LoopFillZerobss:
cmp r2, r4
bcc FillZerobss
/* Call static constructors */
bl __libc_init_array
/* Call the application's entry point.*/
bl main
bx lr
.size Reset_Handler, .-Reset_Handler
... some code
I build the executable project with this cmake file, where I include the .ld file in linking options and the .s file as a source file. Is this approach correct?
...
add_subdirectory(${STLIB_DIR} ${STLIB_DIR}/build)
add_executable(${EXECUTABLE}
${CMAKE_SOURCE_DIR}/Core/Src/main.cpp
${CMAKE_SOURCE_DIR}/Core/Src/syscalls.c
${CMAKE_SOURCE_DIR}/Core/Src/stm32h7xx_hal_msp.c
${CMAKE_SOURCE_DIR}/Core/Src/stm32h7xx_it.c
${CMAKE_SOURCE_DIR}/Core/Src/sysmem.c
${CMAKE_SOURCE_DIR}/Core/Src/system_stm32h7xx.c
${CMAKE_SOURCE_DIR}/Core/Startup/startup_stm32h723zgtx.s
)
target_link_libraries(${EXECUTABLE} ${STLIB_DIR}/build/libst-lib.a)
...
target_link_options(${EXECUTABLE} PUBLIC
-T${CMAKE_SOURCE_DIR}/STM32H723ZGTX_FLASH.ld
-mcpu=cortex-m7
-mthumb
-mfpu=fpv5-d16
-mfloat-abi=hard
-specs=nosys.specs
-lc
-lm
-lnosys
-Wl,-Map=${PROJECT_NAME}.map,--cref
-Wl,--gc-sections
)
