add gcc6

target/config/Config.in.compiler

@@ -98,6 +98,17 @@ config ADK_TOOLCHAIN_GCC_7
 	depends on !ADK_TARGET_ARCH_OR1K
 	depends on !ADK_TARGET_ARCH_LOONGARCH
 
+config ADK_TOOLCHAIN_GCC_6
+	bool "6.5.0"
+	depends on !ADK_TARGET_ARCH_ARC
+	depends on !ADK_TARGET_ARCH_AVR32
+	depends on !ADK_TARGET_ARCH_CSKY
+	depends on !ADK_TARGET_ARCH_HPPA
+	depends on !ADK_TARGET_ARCH_METAG
+	depends on !ADK_TARGET_ARCH_NDS32
+	depends on !ADK_TARGET_ARCH_OR1K
+	depends on !ADK_TARGET_ARCH_LOONGARCH
+
 config ADK_TOOLCHAIN_GCC_ARC
 	bool "arc-2023.09"
 	depends on ADK_TARGET_ARCH_ARC

toolchain/gcc/Makefile.inc

@@ -66,6 +66,14 @@ PKG_RELEASE:=		1
 DISTFILES:=		${PKG_NAME}-${PKG_VERSION}.tar.gz
 LIBSTDCXXVER:=		23
 endif
+ifeq ($(ADK_TOOLCHAIN_GCC_6),y)
+PKG_VERSION:=		6.5.0
+PKG_HASH:=		4eed92b3c24af2e774de94e96993aadbf6761cdf7a0345e59eb826d20a9ebf73
+PKG_SITES:=		${MASTER_SITE_GNU:=gcc/gcc-${PKG_VERSION}/}
+PKG_RELEASE:=		1
+DISTFILES:=		${PKG_NAME}-${PKG_VERSION}.tar.gz
+LIBSTDCXXVER:=		22
+endif
 ifeq ($(ADK_TOOLCHAIN_GCC_ARC),y)
 PKG_VERSION:=		arc-2023.09
 PKG_GIT:=		tag