initial buildroot for linux 5.15

package/libatomic_ops/Config.in

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+config BR2_PACKAGE_LIBATOMIC_OPS_ARCH_SUPPORTS
+	bool
+	default y if BR2_aarch64 || BR2_arm || BR2_armeb
+	default y if BR2_i386 || BR2_x86_64
+	default y if BR2_powerpc || BR2_powerpc64 || BR2_powerpc64le
+	default y if BR2_mips || BR2_mipsel || BR2_mips64 || BR2_mips64el
+	default y if BR2_riscv
+	default y if BR2_sparc || BR2_sparc64
+	# Unsupported for MIPS R6
+	depends on !BR2_MIPS_CPU_MIPS32R6 && !BR2_MIPS_CPU_MIPS64R6
+
+config BR2_PACKAGE_LIBATOMIC_OPS
+	bool "libatomic_ops"
+	depends on BR2_PACKAGE_LIBATOMIC_OPS_ARCH_SUPPORTS
+	help
+	  Atomic operations library
+
+	  https://github.com/ivmai/libatomic_ops

package/libatomic_ops/libatomic_ops.hash

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+# Locally calculated
+sha256  18091d5f3cb7008b0432016390ff437b9d1d76c10b92c8e63ff63f0c1331b030  libatomic_ops-7.6.12.tar.gz
+sha256  f0e630c0ca489767033da5a0c869fb4231db522c5ff479ce55a853a923a00f69  doc/LICENSING.txt
+sha256  8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643  COPYING

package/libatomic_ops/libatomic_ops.mk

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+################################################################################
+#
+# libatomic_ops
+#
+################################################################################
+
+LIBATOMIC_OPS_VERSION = 7.6.12
+LIBATOMIC_OPS_SITE = $(call github,ivmai,libatomic_ops,v$(LIBATOMIC_OPS_VERSION))
+LIBATOMIC_OPS_AUTORECONF = YES
+
+# From doc/LICENSING.txt: "Our intent is to make it easy to use
+# libatomic_ops, in both free and proprietary software.  Hence most
+# code that we expect to be linked into a client application is
+# covered by an MIT-style license. A few library routines are covered
+# by the GNU General Public License. These are put into a separate
+# library, libatomic_ops_gpl.a."
+LIBATOMIC_OPS_LICENSE = MIT (main library) / GPL-2.0+ (gpl extension)
+LIBATOMIC_OPS_LICENSE_FILES = doc/LICENSING.txt COPYING
+LIBATOMIC_OPS_CPE_ID_VENDOR = libatomic_ops_project
+
+LIBATOMIC_OPS_INSTALL_STAGING = YES
+
+ifeq ($(BR2_sparc_v8)$(BR2_sparc_leon3),y)
+LIBATOMIC_OPS_CONF_ENV = CFLAGS="$(TARGET_CFLAGS) -DAO_NO_SPARC_V9"
+endif
+
+$(eval $(autotools-package))
+$(eval $(host-autotools-package))