LPC845 & mcuxpressoide_11.2.0 : lto-wrapper failed

[v_canoz]

Hello,

I need to enable the -flto option for my project using an LPC845.

If I turn on -flto for the C compiler, the C++ compiler and the linker in mcu settings, I get the following error:

Building target: LPC845_Project.axf
Invoking: MCU C++ Linker
arm-none-eabi-c++ -nostdlib -L"C:\Users\Victor\Documents\GitHub\IKM-RL800-01U-mcu\source\driver-S2LP\Sigfox_Libs\bin" -Xlinker -Map="LPC845_Project.map" -Xlinker --gc-sections -Xlinker -print-memory-usage -Xlinker --sort-section=alignment -Xlinker --cref -flto -Os -mcpu=cortex-m0plus -mthumb -T LPC845_Project_Release.ld -o "LPC845_Project.axf" ./utilities/fsl_debug_console.o ./startup/startup_lpc845.o ./source/tasks/task_S2LP.o ./source/tasks/task_at.o ./source/ika_cpp/utils/eng_not/engineeringnotation.o ./source/ika_cpp/utils/aes/AES.o ./source/ika_cpp/ika_log_formatter/ika_log_formatter.o ./source/ika_cpp/freertos_addons/cpp_config.o ./source/ika_cpp/freertos_addons/thread.o ./source/driver-S2LP/S2LP_Library/src/S2LP_Commands.o ./source/driver-S2LP/S2LP_Library/src/S2LP_Csma.o ./source/driver-S2LP/S2LP_Library/src/S2LP_Fifo.o ./source/driver-S2LP/S2LP_Library/src/S2LP_General.o ./source/driver-S2LP/S2LP_Library/src/S2LP_Gpio.o ./source/driver-S2LP/S2LP_Library/src/S2LP_PacketHandler.o ./source/driver-S2LP/S2LP_Library/src/S2LP_PktBasic.o ./source/driver-S2LP/S2LP_Library/src/S2LP_PktStack.o ./source/driver-S2LP/S2LP_Library/src/S2LP_PktWMbus.o ./source/driver-S2LP/S2LP_Library/src/S2LP_Qi.o ./source/driver-S2LP/S2LP_Library/src/S2LP_Radio.o ./source/driver-S2LP/S2LP_Library/src/S2LP_Timer.o ./source/driver-S2LP/S2LP_Library/src/S2LP_Timer_ex.o ./source/driver-S2LP/S2LP_Library/src/S2LP_Types.o ./source/driver-S2LP/driver_s2lp.o ./source/driver-S2LP/sigfox.o ./source/driver-LPC84X/ika_gpio.o ./source/LPC845_Project.o ./source/mtb.o ./source/s2lp_custom_ikm.o ./source/semihost_hardfault.o ./drivers/fsl_clock.o ./drivers/fsl_common.o ./drivers/fsl_gpio.o ./drivers/fsl_iap.o ./drivers/fsl_pint.o ./drivers/fsl_power.o ./drivers/fsl_reset.o ./drivers/fsl_spi.o ./drivers/fsl_swm.o ./drivers/fsl_syscon.o ./drivers/fsl_usart.o ./device/system_LPC845.o ./component/uart/miniusart_adapter.o ./board/board.o ./board/clock_config.o ./board/peripherals.o ./board/pin_mux.o ./amazon-freertos/freertos_kernel/portable/MemMang/heap_4.o ./amazon-freertos/freertos_kernel/portable/GCC/ARM_CM0/port.o ./amazon-freertos/freertos_kernel/croutine.o ./amazon-freertos/freertos_kernel/event_groups.o ./amazon-freertos/freertos_kernel/list.o ./amazon-freertos/freertos_kernel/queue.o ./amazon-freertos/freertos_kernel/stream_buffer.o ./amazon-freertos/freertos_kernel/tasks.o ./amazon-freertos/freertos_kernel/timers.o -lSFX_LIB_MON_CortexM0+ -lADDON_RF_PROTOCOL_MON_CortexM0+
C:\Users\Victor\AppData\Local\Temp\ccEbURjM.s: Assembler messages:
C:\Users\Victor\AppData\Local\Temp\ccEbURjM.s:941: Error: invalid offset, value too big (0x00002C90)
lto-wrapper.exe: fatal error: arm-none-eabi-c++ returned 1 exit status
compilation terminated.
c:/nxp/mcuxpressoide_11.2.0_4120/ide/plugins/com.nxp.mcuxpresso.tools.win32_11.2.0.202001021529/tools/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: error: lto-wrapper failed

What could cause this issue, and how to correct it ?

Thanks,

Victor

[ErichStyger]

Hi Victor,

the reason is that the offset/value for an immediate constant in the assembly code is too big.

I had fixed such things in the FreeRTOS port I'm using (see Tutorial: Adding FreeRTOS to where there is no FreeRTOS | MCU on Eclipse ): this port works even with highest optimization levels and with -flto.

Search for example for '-flto' in McuOnEclipseLibrary/port.c at master · ErichStyger/McuOnEclipseLibrary · GitHub  which has two locations dealing with that optimization level.

You could use/integrate that port (see above article how you can do this even for an SDK which does not have FreeRTOS): otherwise that FreeRTOS port can easily replace your existing one.

I hope this helps,

Erich

[v_canoz]

Hello Erich,

Thanks for your answer. Actually I've read this post long time ago and find it very useful (BTW, very nice blog, it helped us a lot of times!)

However I'm working with the latest version of the FreeRTOS kernel, I would rather like not to change it at this stage of the development (aka very close to the end, missing a few kB of flash to finish it).

1. I don't know how to obtain more debug information from the linker. Is it possible?
2. I'm using this port: FreeRTOS-Kernel/portable/GCC/ARM_CM0 at master · FreeRTOS/FreeRTOS-Kernel · GitHub. Could you please pin-point the location of the problem for this official port? Unfortunately I don't know assembly language...and I can't see any constant matching the offset reported in the linker message.
3. I've opened an issue in the FreeRTOS kernel Github repo: [BUG] -flto optimization fails with ARM_CM0 port (invalid offset, value too big) · Issue #105 · Free.... Feel free to contribute if you have the answer :smileyhappy:

Thanks again,

Victor

[v_canoz]

After new tests, the issue is not related to FreeRTOS at all. It is due to an external static library. I wonder if I can disable -flto only for this library...
I've created a new post for this specific question: https://community.nxp.com/message/1346603