how to create a library compatible with the GNU toolchain

The Keil MDK IDE uses either an:
* open-source "GNU Arm Embedded" Compiler see developer.arm.com/.../gnu-rm
* or Arm Compiler 6 see developer.arm.com/.../version-6

The STM32Cube IDE uses an:
* an enhanced version of the "GNU Arm Embedded" for STM32

...It is never recommended to mix libraries and object files from different compilers.

One other thing, it looks like the STM32Cube IDE may prefer backslashes instead of forward slashes.

Is that is an absolute mast? 1. I prefer to use what I use - i.e armcc v.5.06 b7. For this particular case, I can try armcc v6. What if one has a required library but doesn't have its source?

As an alternative, as you can see I'm using GNU within Keil MDK but still have errors, which I can't resolve..What should I do within MDK to make it happy? I really don't spend any time with Cube. 

Thanks. 

For GCC compiler questions, this might not be the best forum to ask, since most users here are using the Arm Compiler 5 or Arm Compiler 6.

Looking around, it appears symbols like _sbss and _ebss are meant to be defined in a linker script file. See these articles in a series on linker files:

https://interrupt.memfault.com/blog/how-to-write-linker-scripts-for-firmware

https://interrupt.memfault.com/blog/zero-to-main-1

I suggest trying to build a project in Keil using 'gcc-arm-none-eabi-10-2020' , make sure that works, then try building this project.

You also might want to post in the GNU Toolchain forum. For example, this post sets up a .ld file that defines a _ebss - one of the symbols you are missing.

https://community.arm.com/developer/tools-software/oss-platforms/f/gnu-toolchain-forum/45784/how-do-i-implement-multiple-relocate-segments

I added the linker script file used by the Cube project to Keil linker options.. Here is my build output:

Build started: Project: main
*** Note: Rebuilding project, since 'Options->Output->Create Batch File' is selected.
Rebuild target 'mc_comm_lib_mk9p0'
compiling main.c...
compiling system_stm32g4xx.c...
assembling startup_stm32g431xx.asm...
linking...
c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: ./out/startup_stm32g431xx.o: in function `LoopForever':
B:/STM32/G4/Examples/mc_comm_lib GNU mk9p0/../../Nimbus/PAL/SRC/startup_stm32g431xx.asm:87: undefined reference to `_siccmram'
c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: B:/STM32/G4/Examples/mc_comm_lib GNU mk9p0/../../Nimbus/PAL/SRC/startup_stm32g431xx.asm:93: undefined reference to `_sccmram'
c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: B:/STM32/G4/Examples/mc_comm_lib GNU mk9p0/../../Nimbus/PAL/SRC/startup_stm32g431xx.asm:94: undefined reference to `_eccmram'
c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: c:/st/stm32cubeide_1.6.0/stm32cubeide/plugins/com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924/tools/bin/../lib/gcc/arm-none-eabi/9.3.1/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard\libc.a(lib_a-exit.o): in function `exit':
exit.c:(.text.exit+0x16): undefined reference to `_exit'
collect2.exe: error: ld returned 1 exit status
".\OUT\main.elf" - 1 Error(s), 0 Warning(s).
Target not created.
Build Time Elapsed:  00:00:07

I'm attaching the startup file here

/**
  ******************************************************************************
  * @file      startup_stm32g431xx.s
  * @author    MCD Application Team
  * @brief     STM32G431xx devices vector table GCC toolchain.
  *            This module performs:
  *                - Set the initial SP
  *                - Set the initial PC == Reset_Handler,
  *                - Set the vector table entries with the exceptions ISR address,
  *                - Configure the clock system
  *                - Branches to main in the C library (which eventually
  *                  calls main()).
  *            After Reset the Cortex-M4 processor is in Thread mode,
  *            priority is Privileged, and the Stack is set to Main.
  ******************************************************************************
  * @attention
  *
  * <h2><center>© Copyright (c) 2019 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */

  .syntax unified
	.cpu cortex-m4
	.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

.equ  BootRAM,        0xF1E0F85F
/**
 * @brief  This is the code that gets called when the processor first
 *          starts execution following a reset event. Only the absolutely
 *          necessary set is performed, after which the application
 *          supplied main() routine is called.
 * @param  None
 * @retval : None
*/

    .section	.text.Reset_Handler
	.weak	Reset_Handler
	.type	Reset_Handler, %function
Reset_Handler:
  ldr   r0, =_estack
  mov   sp, r0          /* set stack pointer */

/* 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 the clock system intitialization function.*/
    bl  SystemInit
/* Call static constructors */
    bl __libc_init_array
/* Call the application's entry point.*/
	bl	main

LoopForever:
    b LoopForever

.size	Reset_Handler, .-Reset_Handler

/**
 * @brief  This is the code that gets called when the processor receives an
 *         unexpected interrupt.  This simply enters an infinite loop, preserving
 *         the system state for examination by a debugger.
 *
 * @param  None
 * @retval : None
*/
    .section	.text.Default_Handler,"ax",%progbits
Default_Handler:
Infinite_Loop:
	b	Infinite_Loop
	.size	Default_Handler, .-Default_Handler
/******************************************************************************
*
* The minimal vector table for a Cortex-M4.  Note that the proper constructs
* must be placed on this to ensure that it ends up at physical address
* 0x0000.0000.
*
******************************************************************************/
 	.section	.isr_vector,"a",%progbits
	.type	g_pfnVectors, %object
	.size	g_pfnVectors, .-g_pfnVectors


g_pfnVectors:
	.word	_estack
	.word	Reset_Handler
	.word	NMI_Handler
	.word	HardFault_Handler
	.word	MemManage_Handler
	.word	BusFault_Handler
	.word	UsageFault_Handler
	.word	0
	.word	0
	.word	0
	.word	0
	.word	SVC_Handler
	.word	DebugMon_Handler
	.word	0
	.word	PendSV_Handler
	.word	SysTick_Handler
	.word	WWDG_IRQHandler
	.word	PVD_PVM_IRQHandler
	.word	RTC_TAMP_LSECSS_IRQHandler
	.word	RTC_WKUP_IRQHandler
	.word	FLASH_IRQHandler
	.word	RCC_IRQHandler
	.word	EXTI0_IRQHandler
	.word	EXTI1_IRQHandler
	.word	EXTI2_IRQHandler
	.word	EXTI3_IRQHandler
	.word	EXTI4_IRQHandler
	.word	DMA1_Channel1_IRQHandler
	.word	DMA1_Channel2_IRQHandler
	.word	DMA1_Channel3_IRQHandler
	.word	DMA1_Channel4_IRQHandler
	.word	DMA1_Channel5_IRQHandler
	.word	DMA1_Channel6_IRQHandler
	.word	0
	.word	ADC1_2_IRQHandler
	.word	USB_HP_IRQHandler
	.word	USB_LP_IRQHandler
	.word	FDCAN1_IT0_IRQHandler
	.word	FDCAN1_IT1_IRQHandler
	.word	EXTI9_5_IRQHandler
	.word	TIM1_BRK_TIM15_IRQHandler
	.word	TIM1_UP_TIM16_IRQHandler
	.word	TIM1_TRG_COM_TIM17_IRQHandler
	.word	TIM1_CC_IRQHandler
	.word	TIM2_IRQHandler
	.word	TIM3_IRQHandler
	.word	TIM4_IRQHandler
	.word	I2C1_EV_IRQHandler
	.word	I2C1_ER_IRQHandler
	.word	I2C2_EV_IRQHandler
	.word	I2C2_ER_IRQHandler
	.word	SPI1_IRQHandler
	.word	SPI2_IRQHandler
	.word	USART1_IRQHandler
	.word	USART2_IRQHandler
	.word	USART3_IRQHandler
	.word	EXTI15_10_IRQHandler
	.word	RTC_Alarm_IRQHandler
	.word	USBWakeUp_IRQHandler
	.word	TIM8_BRK_IRQHandler
	.word	TIM8_UP_IRQHandler
	.word	TIM8_TRG_COM_IRQHandler
	.word	TIM8_CC_IRQHandler
	.word	0
	.word	0
	.word	LPTIM1_IRQHandler
	.word	0
	.word	SPI3_IRQHandler
	.word	UART4_IRQHandler
	.word	0
	.word	TIM6_DAC_IRQHandler
	.word	TIM7_IRQHandler
	.word	DMA2_Channel1_IRQHandler
	.word	DMA2_Channel2_IRQHandler
	.word	DMA2_Channel3_IRQHandler
	.word	DMA2_Channel4_IRQHandler
	.word	DMA2_Channel5_IRQHandler
	.word	0
	.word	0
	.word	UCPD1_IRQHandler
	.word	COMP1_2_3_IRQHandler
	.word	COMP4_IRQHandler
	.word	0
	.word	0
	.word	0
	.word	0
	.word	0
	.word	0
	.word	0
	.word	0
	.word	0
	.word	CRS_IRQHandler
	.word	SAI1_IRQHandler
	.word	0
	.word	0
	.word	0
	.word	0
	.word	FPU_IRQHandler
	.word	0
	.word	0
	.word	0
	.word	0
	.word	0
	.word	0
	.word	0
	.word	0
	.word	RNG_IRQHandler
	.word	LPUART1_IRQHandler
	.word	I2C3_EV_IRQHandler
	.word	I2C3_ER_IRQHandler
	.word	DMAMUX_OVR_IRQHandler
	.word	0
	.word	0
	.word	DMA2_Channel6_IRQHandler
	.word	0
	.word	0
	.word	CORDIC_IRQHandler
	.word	FMAC_IRQHandler

/*******************************************************************************
*
* Provide weak aliases for each Exception handler to the Default_Handler.
* As they are weak aliases, any function with the same name will override
* this definition.
*
*******************************************************************************/

	.weak	NMI_Handler
	.thumb_set NMI_Handler,Default_Handler

	.weak	HardFault_Handler
	.thumb_set HardFault_Handler,Default_Handler

	.weak	MemManage_Handler
	.thumb_set MemManage_Handler,Default_Handler

	.weak	BusFault_Handler
	.thumb_set BusFault_Handler,Default_Handler

	.weak	UsageFault_Handler
	.thumb_set UsageFault_Handler,Default_Handler

	.weak	SVC_Handler
	.thumb_set SVC_Handler,Default_Handler

	.weak	DebugMon_Handler
	.thumb_set DebugMon_Handler,Default_Handler

	.weak	PendSV_Handler
	.thumb_set PendSV_Handler,Default_Handler

	.weak	SysTick_Handler
	.thumb_set SysTick_Handler,Default_Handler

	.weak	WWDG_IRQHandler
	.thumb_set WWDG_IRQHandler,Default_Handler

	.weak	PVD_PVM_IRQHandler
	.thumb_set PVD_PVM_IRQHandler,Default_Handler

	.weak	RTC_TAMP_LSECSS_IRQHandler
	.thumb_set RTC_TAMP_LSECSS_IRQHandler,Default_Handler

	.weak	RTC_WKUP_IRQHandler
	.thumb_set RTC_WKUP_IRQHandler,Default_Handler

	.weak	FLASH_IRQHandler
	.thumb_set FLASH_IRQHandler,Default_Handler

	.weak	RCC_IRQHandler
	.thumb_set RCC_IRQHandler,Default_Handler

	.weak	EXTI0_IRQHandler
	.thumb_set EXTI0_IRQHandler,Default_Handler

	.weak	EXTI1_IRQHandler
	.thumb_set EXTI1_IRQHandler,Default_Handler

	.weak	EXTI2_IRQHandler
	.thumb_set EXTI2_IRQHandler,Default_Handler

	.weak	EXTI3_IRQHandler
	.thumb_set EXTI3_IRQHandler,Default_Handler

	.weak	EXTI4_IRQHandler
	.thumb_set EXTI4_IRQHandler,Default_Handler

	.weak	DMA1_Channel1_IRQHandler
	.thumb_set DMA1_Channel1_IRQHandler,Default_Handler

	.weak	DMA1_Channel2_IRQHandler
	.thumb_set DMA1_Channel2_IRQHandler,Default_Handler

	.weak	DMA1_Channel3_IRQHandler
	.thumb_set DMA1_Channel3_IRQHandler,Default_Handler

	.weak	DMA1_Channel4_IRQHandler
	.thumb_set DMA1_Channel4_IRQHandler,Default_Handler

	.weak	DMA1_Channel5_IRQHandler
	.thumb_set DMA1_Channel5_IRQHandler,Default_Handler

	.weak	DMA1_Channel6_IRQHandler
	.thumb_set DMA1_Channel6_IRQHandler,Default_Handler

	.weak	ADC1_2_IRQHandler
	.thumb_set ADC1_2_IRQHandler,Default_Handler

	.weak	USB_HP_IRQHandler
	.thumb_set USB_HP_IRQHandler,Default_Handler

	.weak	USB_LP_IRQHandler
	.thumb_set USB_LP_IRQHandler,Default_Handler

	.weak	FDCAN1_IT0_IRQHandler
	.thumb_set FDCAN1_IT0_IRQHandler,Default_Handler

	.weak	FDCAN1_IT1_IRQHandler
	.thumb_set FDCAN1_IT1_IRQHandler,Default_Handler

	.weak	EXTI9_5_IRQHandler
	.thumb_set EXTI9_5_IRQHandler,Default_Handler

	.weak	TIM1_BRK_TIM15_IRQHandler
	.thumb_set TIM1_BRK_TIM15_IRQHandler,Default_Handler

	.weak	TIM1_UP_TIM16_IRQHandler
	.thumb_set TIM1_UP_TIM16_IRQHandler,Default_Handler

	.weak	TIM1_TRG_COM_TIM17_IRQHandler
	.thumb_set TIM1_TRG_COM_TIM17_IRQHandler,Default_Handler

	.weak	TIM1_CC_IRQHandler
	.thumb_set TIM1_CC_IRQHandler,Default_Handler

	.weak	TIM2_IRQHandler
	.thumb_set TIM2_IRQHandler,Default_Handler

	.weak	TIM3_IRQHandler
	.thumb_set TIM3_IRQHandler,Default_Handler

	.weak	TIM4_IRQHandler
	.thumb_set TIM4_IRQHandler,Default_Handler

	.weak	I2C1_EV_IRQHandler
	.thumb_set I2C1_EV_IRQHandler,Default_Handler

	.weak	I2C1_ER_IRQHandler
	.thumb_set I2C1_ER_IRQHandler,Default_Handler

	.weak	I2C2_EV_IRQHandler
	.thumb_set I2C2_EV_IRQHandler,Default_Handler

	.weak	I2C2_ER_IRQHandler
	.thumb_set I2C2_ER_IRQHandler,Default_Handler

	.weak	SPI1_IRQHandler
	.thumb_set SPI1_IRQHandler,Default_Handler

	.weak	SPI2_IRQHandler
	.thumb_set SPI2_IRQHandler,Default_Handler

	.weak	USART1_IRQHandler
	.thumb_set USART1_IRQHandler,Default_Handler

	.weak	USART2_IRQHandler
	.thumb_set USART2_IRQHandler,Default_Handler

	.weak	USART3_IRQHandler
	.thumb_set USART3_IRQHandler,Default_Handler

	.weak	EXTI15_10_IRQHandler
	.thumb_set EXTI15_10_IRQHandler,Default_Handler

	.weak	RTC_Alarm_IRQHandler
	.thumb_set RTC_Alarm_IRQHandler,Default_Handler

	.weak	USBWakeUp_IRQHandler
	.thumb_set USBWakeUp_IRQHandler,Default_Handler

	.weak	TIM8_BRK_IRQHandler
	.thumb_set TIM8_BRK_IRQHandler,Default_Handler

	.weak	TIM8_UP_IRQHandler
	.thumb_set TIM8_UP_IRQHandler,Default_Handler

	.weak	TIM8_TRG_COM_IRQHandler
	.thumb_set TIM8_TRG_COM_IRQHandler,Default_Handler

	.weak	TIM8_CC_IRQHandler
	.thumb_set TIM8_CC_IRQHandler,Default_Handler

	.weak	LPTIM1_IRQHandler
	.thumb_set LPTIM1_IRQHandler,Default_Handler

	.weak	SPI3_IRQHandler
	.thumb_set SPI3_IRQHandler,Default_Handler

	.weak	UART4_IRQHandler
	.thumb_set UART4_IRQHandler,Default_Handler

	.weak	TIM6_DAC_IRQHandler
	.thumb_set TIM6_DAC_IRQHandler,Default_Handler

	.weak	TIM7_IRQHandler
	.thumb_set TIM7_IRQHandler,Default_Handler

	.weak	DMA2_Channel1_IRQHandler
	.thumb_set DMA2_Channel1_IRQHandler,Default_Handler

	.weak	DMA2_Channel2_IRQHandler
	.thumb_set DMA2_Channel2_IRQHandler,Default_Handler

	.weak	DMA2_Channel3_IRQHandler
	.thumb_set DMA2_Channel3_IRQHandler,Default_Handler

	.weak	DMA2_Channel4_IRQHandler
	.thumb_set DMA2_Channel4_IRQHandler,Default_Handler

	.weak	DMA2_Channel5_IRQHandler
	.thumb_set DMA2_Channel5_IRQHandler,Default_Handler

	.weak	UCPD1_IRQHandler
	.thumb_set UCPD1_IRQHandler,Default_Handler

	.weak	COMP1_2_3_IRQHandler
	.thumb_set COMP1_2_3_IRQHandler,Default_Handler

	.weak	COMP4_IRQHandler
	.thumb_set COMP4_IRQHandler,Default_Handler

	.weak	CRS_IRQHandler
	.thumb_set CRS_IRQHandler,Default_Handler

	.weak	SAI1_IRQHandler
	.thumb_set SAI1_IRQHandler,Default_Handler

	.weak	FPU_IRQHandler
	.thumb_set FPU_IRQHandler,Default_Handler

	.weak	RNG_IRQHandler
	.thumb_set RNG_IRQHandler,Default_Handler

	.weak	LPUART1_IRQHandler
	.thumb_set LPUART1_IRQHandler,Default_Handler

	.weak	I2C3_EV_IRQHandler
	.thumb_set I2C3_EV_IRQHandler,Default_Handler

	.weak	I2C3_ER_IRQHandler
	.thumb_set I2C3_ER_IRQHandler,Default_Handler

	.weak	DMAMUX_OVR_IRQHandler
	.thumb_set DMAMUX_OVR_IRQHandler,Default_Handler

	.weak	DMA2_Channel6_IRQHandler
	.thumb_set DMA2_Channel6_IRQHandler,Default_Handler

	.weak	CORDIC_IRQHandler
	.thumb_set CORDIC_IRQHandler,Default_Handler

	.weak	FMAC_IRQHandler
	.thumb_set FMAC_IRQHandler,Default_Handler

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

I copied ld file from the Cube project and have some improvements:

c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: c:/st/stm32cubeide_1.6.0/stm32cubeide/plugins/com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924/tools/bin/../lib/gcc/arm-none-eabi/9.3.1/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard\libc.a(lib_a-exit.o): in function `exit':

I'm sure that my problem is incorrect linker settings. What are the correct ones?

-T ./stm32g4_flash.ld -mcpu=cortex-m4 -mthumb -mthumb-interwork -Wl,-Map="./main.map" 
-o ./OUT/main.elf 

Build started: Project: main
Build target 'mc_comm_lib_mk9p0'
compiling system_stm32g4xx.c...
compiling main.c...
linking...
c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: error: ./OUT/main.elf uses VFP register arguments, c:/ST/STM32CubeIDE_1.6.0/STM32CubeIDE/plugins/com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924/tools/arm-none-eabi/lib/\libc.a(lib_a-init.o) does not
c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: failed to merge target specific data of file c:/ST/STM32CubeIDE_1.6.0/STM32CubeIDE/plugins/com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924/tools/arm-none-eabi/lib/\libc.a(lib_a-init.o)
c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: error: ./OUT/main.elf uses VFP register arguments, c:/ST/STM32CubeIDE_1.6.0/STM32CubeIDE/plugins/com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924/tools/arm-none-eabi/lib/\libc.a(lib_a-memcpy-stub.o) does not
c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: failed to merge target specific data of file c:/ST/STM32CubeIDE_1.6.0/STM32CubeIDE/plugins/com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924/tools/arm-none-eabi/lib/\libc.a(lib_a-memcpy-stub.o)
c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: error: ./OUT/main.elf uses VFP register arguments, c:/ST/STM32CubeIDE_1.6.0/STM32CubeIDE/plugins/com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924/tools/arm-none-eabi/lib/\libc.a(lib_a-memset.o) does not
c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: failed to merge target specific data of file c:/ST/STM32CubeIDE_1.6.0/STM32CubeIDE/plugins/com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924/tools/arm-none-eabi/lib/\libc.a(lib_a-memset.o)
c:\st\stm32cubeide_1.6.0\stm32cubeide\plugins\com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924\tools\arm-none-eabi\bin\ld.exe: c:/ST/STM32CubeIDE_1.6.0/STM32CubeIDE/plugins/com.st.stm32cube.ide.mcu.externaltools.gnu-tools-for-stm32.9-2020-q2-update.win32_1.5.0.202011040924/tools/arm-none-eabi/lib/\libc.a(lib_a-init.o): in function `__libc_init_array':
init.c:(.text.__libc_init_array+0x20): undefined reference to `_init'
collect2.exe: error: ld returned 1 exit status
".\OUT\main.elf" - 1 Error(s), 0 Warning(s).
Target not created.
Build Time Elapsed:  00:00:02