toolchain/uClibc/patches-0.9.32/950-detect_bx_availibility.patch

   1 The "use BX" option is now a suggestion that BX be used if available.
   2 Use a macro to detect if BX is available at build time. If so, and
   3 the user requested it be used, then use it. Otherwise, error out.
   4
   5 Macro courtesy Khem RAJ:
   6   http://lists.uclibc.org/pipermail/uclibc/2009-April/042301.html
   7
   8 Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
   9 Cc: Khem Raj <raj.khem@gmail.com>
  10 Cc: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
  11 Cc: Carmelo AMOROSO <carmelo.amoroso@st.com>
  12 ---
  13  extra/Configs/Config.arm              |    4 +++-
  14  libc/sysdeps/linux/arm/bits/arm_asm.h |    9 ++++++++-
  15  2 files changed, 11 insertions(+), 2 deletions(-)
  16
  17 diff --git a/extra/Configs/Config.arm b/extra/Configs/Config.arm
  18 index 227b90c..9aa9e56 100644
  19 --- a/extra/Configs/Config.arm
  20 +++ b/extra/Configs/Config.arm
  21 @@ -33,4 +33,6 @@ config COMPILE_IN_THUMB_MODE
  22  config USE_BX
  23         bool "Use BX in function return"
  24         help
  25 -         Use BX instruction for THUMB aware architectures.
  26 +         Say 'y' to use BX to return from functions on your thumb-aware
  27 +         processor. Say 'y' if you need to use interworking. Say 'n' if not.
  28 +         It is safe to say 'y' even if you're not doing interworking.
  29 diff --git a/libc/sysdeps/linux/arm/bits/arm_asm.h b/libc/sysdeps/linux/arm/bits/arm_asm.h
  30 index 1d87df6..921c9a3 100644
  31 --- a/libc/sysdeps/linux/arm/bits/arm_asm.h
  32 +++ b/libc/sysdeps/linux/arm/bits/arm_asm.h
  33 @@ -24,5 +24,12 @@
  34  #define THUMB1_ONLY 1
  35  #endif
  36
  37 -#endif /* _ARM_ASM_H */
  38 +#if defined(__USE_BX__)
  39 +# if (   defined (__ARM_ARCH_2__)  || defined (__ARM_ARCH_3__) \
  40 +      || defined (__ARM_ARCH_3M__) || defined (__ARM_ARCH_4__) \
  41 +     )
  42 +#  error Use of BX was requested, but is not available on the target processor.
  43 +# endif /* ARCH level */
  44 +#endif /* __USE_BX__ */
  45
  46 +#endif /* _ARM_ASM_H */
  47 --
  48 1.7.1
  49