Commit e4b1fa69 authored by Yann E. MORIN's avatar Yann E. MORIN Committed by Thomas Petazzoni
Browse files

arch/arm: VFP and Thumb1 are not compatible 



gcc will refuse to build with both --with-mode=thumb and --with-fpu=vfp,
with error messages during ./configure, like:

    checking for suffix of object files... configure: error: in `/home/ymor
    in/dev/buildroot/O/build/host-gcc-initial-4.9.3/build/arm-buildroot-lin
    ux-uclibcgnueabihf/libgcc':
    configure: error: cannot compute suffix of object files: cannot compile
    See `config.log' for more details.

And config.log informatively contains:

    sorry, unimplemented: Thumb-1 hard-float VFP ABI

This is an error message that comes deep from gcc source files.

If gcc says it does not support VFP with Thumb1, then let's disable that
combination in our menuconfig.

Prefer VFP over Thumb1, i.e. hide Thumb1 when we're not soft-float.

Signed-off-by: default avatar"Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Gustavo Zacarias <gustavo@zacarias.com.ar>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: default avatarArnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
parent 4f7f86fb

arch/Config.in.arm

+6 −0
Original line number Diff line number Diff line
@@ -377,12 +377,18 @@ config BR2_ARM_INSTRUCTIONS_ARM 
config BR2_ARM_INSTRUCTIONS_THUMB

	bool "Thumb"

	depends on BR2_ARM_CPU_HAS_THUMB

	# Thumb-1 and VFP are not compatible

	depends on BR2_ARM_SOFT_FLOAT

	help

	  This option instructions the compiler to generate Thumb

	  instructions, which allows to mix 16 bits instructions and

	  32 bits instructions. This generally provides a much smaller

	  compiled binary size.



comment "Thumb1 is not compatible with VFP"

	depends on BR2_ARM_CPU_HAS_THUMB

	depends on !BR2_ARM_SOFT_FLOAT



config BR2_ARM_INSTRUCTIONS_THUMB2

	bool "Thumb2"

	depends on BR2_ARM_CPU_HAS_THUMB2