diff options
| author | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2016-03-20 17:58:35 +0100 |
|---|---|---|
| committer | Waldemar Brodkorb <wbx@openadk.org> | 2016-03-31 19:35:13 +0200 |
| commit | feb9f08cfe8ddd1fd4fb62265e17ee35147ab268 (patch) | |
| tree | da452e5e8aa09cd6ef0c9d9d83033a8d4f3d623c /extra/Configs/Config.arm | |
| parent | 4ab024d22980cf493dc95a089353df6ebc743f46 (diff) | |
arm: simplify handling of Thumb related options
Currently, the Thumb support on ARM has three related Config.in
options, which are not trivial for users to understand, and are in
fact not needed:
- The USE_BX option is not needed: knowing whether BX is available or
not is easy. If you have an ARM > v4 or ARMv4T, then BX is
available, otherwise it's not. This is the logic used in glibc.
- The USE_LDREXSTREX option is not needed: whenever Thumb2 is
available, ldrex/strex are available, so we can simply rely on
__thumb2__ to determine whether ldrex/strex should be used, without
requiring a Config.in option.
- Once USE_BX and USE_LDREXSTREX are removed, the only thing left
that COMPILE_IN_THUMB does is to set -mthumb. This makes the option
unnecessary, as on ARM at least, the user is already supposed to
pass -march=<foo> or other compiler options tuning the library for
a specific ARM variant. There is no reason to do otherwise for
Thumb, which allows to get rid of the COMPILE_IN_THUMB option.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Diffstat (limited to 'extra/Configs/Config.arm')
| -rw-r--r-- | extra/Configs/Config.arm | 22 |
1 files changed, 0 insertions, 22 deletions
diff --git a/extra/Configs/Config.arm b/extra/Configs/Config.arm index 00cf98281..0d02e3f10 100644 --- a/extra/Configs/Config.arm +++ b/extra/Configs/Config.arm @@ -24,25 +24,3 @@ config CONFIG_ARM_EABI If you say 'n' here, then the library will be built for the old Linux ABI. - -config COMPILE_IN_THUMB_MODE - bool "Build using Thumb mode" - select USE_BX - select USE_LDREXSTREX - help - Say 'y' here to force building uClibc in thumb mode. - Say 'n' to use your compiler's default mode. - -config USE_BX - bool "Use BX in function return" - help - Say 'y' to use BX to return from functions on your thumb-aware - processor. Say 'y' if you need to use interworking. Say 'n' if not. - It is safe to say 'y' even if you're not doing interworking. - -config USE_LDREXSTREX - bool "Use load-store exclusive ASM ops (not supported in SmartFusion)" - depends on COMPILE_IN_THUMB_MODE - default n - help - Say 'y' to use LDREX/STREX ASM ops. |