SW4STM32 and SW4Linux fully supports the STM32MP1 asymmetric multicore Cortex/A7+M4 MPUs

   With System Workbench for Linux, Embedded Linux on the STM32MP1 family of MPUs from ST was never as simple to build and maintain, even for newcomers in the Linux world. And, if you install System Workbench for Linux in System Workbench for STM32 you can seamlessly develop and debug asymmetric applications running partly on Linux, partly on the Cortex-M4.
You can get more information from the ac6-tools website and download (registration required) various documents highlighting:

System Workbench for STM32

Compatibility issues, changed toolset from "Cross ARM GNU C" to "MCU GCC"

I changed the tooset to MCU GCC because the examples and tools from STM comes ready for SW4STM32 which includes the MCU GCC.
Previously I worked with Cross ARM GNU C.
I cleaned up also the whole project. It compiles without any errors or warnings. The application is to control a display 320x240.

I compared the settings:

Settings Now (makes me sad)
MCU GCC Compiler
-mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -std=c99 -Dweak=attributeweak -Dpacked=attributepacked -DUSE_HAL_DRIVER -DSTM32F429xx -I../Inc -I../Drivers/STM32F4xx_HAL_Driver/Inc -I../Drivers/STM32F4xx_HAL_Driver/Inc/Legacy -I../Drivers/CMSIS/Device/ST/STM32F4xx/Include -I../Drivers/CMSIS/Include -I../Utilities/Fonts -I../Drivers/BSP/Components/ili9341 -I../Drivers/BSP/STM32F429I-Discovery -Og -g3 -Wall -fmessage-length=0 -ffunction-sections -c -fmessage-length=0

MCU GCC Linker
-mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -specs=nosys.specs -specs=nano.specs -T”../STM32F429ZITx_FLASH.ld” -Wl,-Map=output.map -Wl,--gc-sections -lm

MCU GCC Assembler
-mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -g

different compared to “Settings Previous”
-mfloat-abi=hard // ARM Options
-mfpu=fpv4-sp-d16 // MIPS Options

Settings Previous
Cross ARM GNU C Compiler
-mcpu=cortex-m4 -mthumb -Og -fmessage-length=0 -fsigned-char -ffunction-sections -fdata-sections -ffreestanding -fno-move-loop-invariants -Wall -Wextra -g3 -DDEBUG -DTRACE -DSTM32F429xx -DUSE_HAL_DRIVER -I”../Inc” -I”../system/Inc” -I”../system/Inc/cmsis” -I”../system/Inc/DEVICE” -std=gnu11 -MMD -MP -MF”$(@:%.o=%.d)” -MT”$(@)” -c -o “$@” “$



What makes you sad in the MCU GCC options?

The -mfpu=fpv4-sp-d16 is just selecting the FPU for the Cortex-M4 (ARM FPU version 4, single precision only, with 16 double-precision registers). It may also be a MIPS option but here it really is an ARM option.

The differences in the options with those for the Cross ARM GNU Compiler are in part due to the fact that you compiled then for a plain Corts-M4, without the optional FPU, while selecting the STM32F429 for MCU GCC selects the proper FPU. A few others are needed for the ST-provided firmwares to compile correctly (like the weak and packed macro definitions or the various -I options).

Bernard (Ac6)

Happily today nothings makes me sad anymore about the MCU GCC options.

In fact the faulty behaviour was due to mixed up content in source files.

Tx for response. According to the response it looks like the MCU GCC is the better choice for STMF4 or STM uCs at all due to proper setting options.