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| author | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2013-07-16 10:03:22 +0200 |
|---|---|---|
| committer | Peter Korsgaard <jacmet@sunsite.dk> | 2013-07-16 15:28:03 +0200 |
| commit | 85d0769ac5cb50527c5bbab4417262064971073f (patch) | |
| tree | 06b04d5cd48397df61b840e78876b98263796a8b /arch/Config.in.arm | |
| parent | d2e3cc389d47f3f1f3aa5e92e2e00deb9f2f27ba (diff) | |
arch/arm: add support for Thumb2
Until now, we were using the default ARM instruction set, as used by
the toolchain: the 32 bits ARM instruction set for the internal
backend, and for external toolchain, whatever default was chosen when
the toolchain was generated.
This commit adds support for the Thumb2 instruction set. To do so, it:
* provides a menuconfig choice between ARM and Thumb2. The choice is
only shown when Thumb2 is supported, i.e on ARMv7-A CPUs.
* passes the --with-mode={arm,thumb} option when building gcc in the
internal backend. This tells the compiler which type of
instructions it should generate.
* passes the m{arm,thumb} option in the external toolchain
wrapper. ARM and Thumb2 code can freely be mixed together, so the
fact that the C library has been built either ARM or Thumb2 and
that the rest of the code is built Thumb2 or ARM is not a problem.
[Peter: fix empty BR2_GCC_TARGET_MODE check]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Diffstat (limited to 'arch/Config.in.arm')
| -rw-r--r-- | arch/Config.in.arm | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/Config.in.arm b/arch/Config.in.arm index 2b493c093..94c32c967 100644 --- a/arch/Config.in.arm +++ b/arch/Config.in.arm @@ -31,6 +31,9 @@ config BR2_ARM_CPU_HAS_VFPV4 bool select BR2_ARM_CPU_HAS_VFPV3 +config BR2_ARM_CPU_HAS_THUMB2 + bool + choice prompt "Target Architecture Variant" depends on BR2_arm || BR2_armeb @@ -65,22 +68,27 @@ config BR2_cortex_a5 bool "cortex-A5" select BR2_ARM_CPU_MAYBE_HAS_NEON select BR2_ARM_CPU_MAYBE_HAS_VFPV4 + select BR2_ARM_CPU_HAS_THUMB2 config BR2_cortex_a7 bool "cortex-A7" select BR2_ARM_CPU_HAS_NEON select BR2_ARM_CPU_HAS_VFPV4 + select BR2_ARM_CPU_HAS_THUMB2 config BR2_cortex_a8 bool "cortex-A8" select BR2_ARM_CPU_HAS_NEON select BR2_ARM_CPU_HAS_VFPV3 + select BR2_ARM_CPU_HAS_THUMB2 config BR2_cortex_a9 bool "cortex-A9" select BR2_ARM_CPU_MAYBE_HAS_NEON select BR2_ARM_CPU_MAYBE_HAS_VFPV3 + select BR2_ARM_CPU_HAS_THUMB2 config BR2_cortex_a15 bool "cortex-A15" select BR2_ARM_CPU_HAS_NEON select BR2_ARM_CPU_HAS_VFPV4 + select BR2_ARM_CPU_HAS_THUMB2 config BR2_fa526 bool "fa526/626" config BR2_pj4 @@ -275,6 +283,30 @@ config BR2_ARM_FPU_NEON_VFPV4 endchoice +choice + prompt "ARM instruction set" + depends on BR2_ARM_CPU_HAS_THUMB2 + +config BR2_ARM_INSTRUCTIONS_ARM_CHOICE + bool "ARM" + help + This option instructs the compiler to generate regular ARM + instructions, that are all 32 bits wide. + +config BR2_ARM_INSTRUCTIONS_THUMB2 + bool "Thumb2" + help + This option instructions the compiler to generate Thumb2 + instructions, which allows to mix 16 bits instructions and + 32 bits instructions. This generally provides a much smaller + compiled binary size. + +endchoice + +config BR2_ARM_INSTRUCTIONS_ARM + def_bool y + depends on !BR2_ARM_INSTRUCTIONS_THUMB2 + config BR2_ARCH default "arm" if BR2_arm default "armeb" if BR2_armeb @@ -344,3 +376,7 @@ config BR2_GCC_TARGET_FLOAT_ABI default "soft" if BR2_ARM_SOFT_FLOAT default "softfp" if !BR2_ARM_SOFT_FLOAT && BR2_ARM_EABI default "hard" if !BR2_ARM_SOFT_FLOAT && BR2_ARM_EABIHF + +config BR2_GCC_TARGET_MODE + default "arm" if BR2_ARM_INSTRUCTIONS_ARM + default "thumb" if BR2_ARM_INSTRUCTIONS_THUMB2 |