| 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 | --- a/extra/Configs/Config.arm |
| 18 | +++ b/extra/Configs/Config.arm |
| 19 | @@ -33,4 +33,6 @@ config COMPILE_IN_THUMB_MODE |
| 20 | config USE_BX |
| 21 | bool "Use BX in function return" |
| 22 | help |
| 23 | - Use BX instruction for THUMB aware architectures. |
| 24 | + Say 'y' to use BX to return from functions on your thumb-aware |
| 25 | + processor. Say 'y' if you need to use interworking. Say 'n' if not. |
| 26 | + It is safe to say 'y' even if you're not doing interworking. |
| 27 | --- a/libc/sysdeps/linux/arm/bits/arm_asm.h |
| 28 | +++ b/libc/sysdeps/linux/arm/bits/arm_asm.h |
| 29 | @@ -24,5 +24,12 @@ |
| 30 | #define THUMB1_ONLY 1 |
| 31 | #endif |
| 32 | |
| 33 | -#endif /* _ARM_ASM_H */ |
| 34 | +#if defined(__USE_BX__) |
| 35 | +# if ( defined (__ARM_ARCH_2__) || defined (__ARM_ARCH_3__) \ |
| 36 | + || defined (__ARM_ARCH_3M__) || defined (__ARM_ARCH_4__) \ |
| 37 | + ) |
| 38 | +# error Use of BX was requested, but is not available on the target processor. |
| 39 | +# endif /* ARCH level */ |
| 40 | +#endif /* __USE_BX__ */ |
| 41 | |
| 42 | +#endif /* _ARM_ASM_H */ |
| 43 | |
