avr32: support uClibc 0.9.33.2

Add a uClibc patch from OpenWRT, and tweak an existing patch to cope with
the lack of a dup3 Linux syscall on avr32. This allow uClibc 0.9.33.2 to be
built for avr32.

[Peter: add upstream url for openwrt patch]
Signed-off-by: Simon Dawson <spdawson@gmail.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

toolchain/toolchain-buildroot/Config.in.2

@@ -68,7 +68,7 @@ config BR2_TOOLCHAIN_BUILDROOT_USE_SSP
 
 choice
 	prompt "Thread library implementation"
-	default BR2_PTHREADS_NATIVE if (!BR2_UCLIBC_VERSION_0_9_31) && !BR2_ARM_OABI && !BR2_xtensa
+	default BR2_PTHREADS_NATIVE if (!BR2_UCLIBC_VERSION_0_9_31) && !BR2_ARM_OABI && !(BR2_avr32 || BR2_xtensa)
 	default BR2_PTHREADS_OLD
 	help
 	  Use this option to select the thread library implementation
@@ -95,6 +95,7 @@ choice
 		depends on !BR2_UCLIBC_VERSION_0_9_31
 		depends on !BR2_ARM_OABI
 		depends on !BR2_x86_i386
+		depends on !BR2_avr32
 		depends on !BR2_xtensa
 endchoice
 

toolchain/uClibc/Config.in

@@ -5,7 +5,6 @@ comment "uClibc Options"
 
 choice
 	prompt "uClibc C library Version"
-	default BR2_UCLIBC_VERSION_0_9_31 if BR2_avr32 # 0.9.32 broken
 	default BR2_UCLIBC_VERSION_0_9_33
 	help
 	  Select the version of uClibc you wish to use.
@@ -20,7 +19,7 @@ choice
 
 	config BR2_UCLIBC_VERSION_0_9_33
 		bool "uClibc 0.9.33.x"
-		depends on !(BR2_avr32 || BR2_xtensa)
+		depends on !BR2_xtensa
 
 	config BR2_UCLIBC_VERSION_SNAPSHOT
 		bool "daily snapshot"

toolchain/uClibc/uClibc-0.9.33.2-OpenWRT-140-avr32_atomic_fix.patch

@@ -0,0 +1,16 @@
+Patch from OpenWRT for avr32.
+
+https://dev.openwrt.org/browser/trunk/toolchain/uClibc/patches-0.9.32/140-avr32_atomic_fix.patch
+
+Signed-off-by: Simon Dawson <spdawson@gmail.com>
+
+--- a/libc/sysdeps/linux/avr32/bits/atomic.h
++++ b/libc/sysdeps/linux/avr32/bits/atomic.h
+@@ -28,6 +28,7 @@ typedef uintmax_t uatomic_max_t;
+ 
+ #define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval)	\
+ 	({								\
++		__uint32_t __result;					\
+ 		__typeof__(*(mem)) __prev;				\
+ 		__asm__ __volatile__(					\
+ 			"/* __arch_compare_and_exchange_val_32_acq */\n" \

toolchain/uClibc/uClibc-0.9.33.2-dup3.patch

@@ -29,7 +29,7 @@ new file mode 100644
 index 0000000..5fdab2e
 --- /dev/null
 +++ b/libc/sysdeps/linux/common/dup3.c
-@@ -0,0 +1,15 @@
+@@ -0,0 +1,17 @@
 +/* vi: set sw=4 ts=4: */
 +/*
 + * dup3() for uClibc
@@ -43,8 +43,10 @@ index 0000000..5fdab2e
 +#include <unistd.h>
 +
 +
++#ifdef __NR_dup3
 +_syscall3(int, dup3, int, oldfd, int, newfd, int, flags)
 +libc_hidden_def(dup3)
++#endif
 -- 
 1.7.5.4