From 4fc56b1d14ffb5e48956dfdd0ce10cd9ac5dd6b6 Mon Sep 17 00:00:00 2001
From: "Yann E. MORIN\"" <yann.morin.1998@anciens.enib.fr>
Date: Wed, 19 Oct 2011 15:27:32 +1300
Subject: arch: add softfp support

Some architectures support a mixed hard/soft floating point, where
the compiler emits hardware floating point instructions, but passes
the operands in core (aka integer) registers.

For example, ARM supports this mode (to come in the next changeset).

Add support for softfp cross compilers to the GCC and GLIBC
configuration. Needed for Ubuntu and other distros that are softfp.

Signed-off-by: Michael Hope <michael.hope@linaro.org>
[yann.morin.1998@anciens.enib.fr: split the original patch]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

diff --git a/config/target.in b/config/target.in
index d38e4c1..b94db3c 100644
--- a/config/target.in
+++ b/config/target.in
@@ -15,6 +15,7 @@ config ARCH_SUPPORT_ABI
 config ARCH_SUPPORT_CPU
 config ARCH_SUPPORT_TUNE
 config ARCH_SUPPORT_FPU
+config ARCH_SUPPORT_SOFTFP
 
 config ARCH_DEFAULT_HAS_MMU
 config ARCH_DEFAULT_BE
@@ -144,6 +145,9 @@ config ARCH_SUPPORT_TUNE
 config ARCH_SUPPORT_FPU
     bool
 
+config ARCH_SUPPORT_SOFTFP
+    bool
+
 config ARCH_ARCH
     string
     prompt "Architecture level"
@@ -271,6 +275,22 @@ config ARCH_FLOAT_SW
       If your processor has no FPU, then you most probably want this, as it
       is faster than emulating the FPU in the kernel.
 
+config ARCH_FLOAT_SOFTFP
+    bool
+    prompt "softfp"
+    depends on ARCH_SUPPORT_SOFTFP
+    help
+      Emit hardware floating point opcodes but use the software
+      floating point calling convention.
+
+      Architectures such as ARM use different registers for passing
+      floating point values depending on if they're in software mode
+      or hardware mode.  softfp emits FPU instructions but uses the
+      software FP calling convention allowing softfp code to
+      interoperate with legacy software only code.
+
+      If in doubt, use 'software' or 'hardware' mode instead.
+
 endchoice
 
 config TARGET_CFLAGS
@@ -300,6 +320,7 @@ config ARCH_FLOAT
     string
     default "hard"   if ARCH_FLOAT_HW
     default "soft"   if ARCH_FLOAT_SW
+    default "softfp" if ARCH_FLOAT_SOFTFP
 
 source "config.gen/arch.in.2"
 
diff --git a/scripts/build/libc/glibc-eglibc.sh-common b/scripts/build/libc/glibc-eglibc.sh-common
index d306fd0..8929f5c 100644
--- a/scripts/build/libc/glibc-eglibc.sh-common
+++ b/scripts/build/libc/glibc-eglibc.sh-common
@@ -135,6 +135,7 @@ do_libc_backend() {
     case "${CT_ARCH_FLOAT}" in
         hard)   extra_config+=("--with-fp");;
         soft)   extra_config+=("--without-fp");;
+        softfp) extra_config+=("--with-fp");;
     esac
 
     if [ "${CT_LIBC_DISABLE_VERSIONING}" = "y" ]; then
diff --git a/scripts/functions b/scripts/functions
index f4b19ca..63c0423 100644
--- a/scripts/functions
+++ b/scripts/functions
@@ -993,6 +993,10 @@ CT_DoBuildTargetTuple() {
             CT_ARCH_FLOAT_CFLAG="-msoft-float"
             CT_ARCH_WITH_FLOAT="--with-float=soft"
             ;;
+        softfp)
+            CT_ARCH_FLOAT_CFLAG="-mfloat-abi=softfp"
+            CT_ARCH_WITH_FLOAT="--with-float=softfp"
+            ;;
     esac
 
     # Build the default kernel tuple part
-- 
cgit v0.10.2-6-g49f6