Update from 2013.01 to 2013.07

[karo-tx-uboot.git] / arch / arm / lib / sections.c

diff --git a/arch/arm/lib/sections.c b/arch/arm/lib/sections.c
new file mode 100644 (file)
index 0000000..e35687c
--- /dev/null
+++ b/arch/arm/lib/sections.c
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2013 Albert ARIBAUD <albert.u.boot@aribaud.net>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+/**
+ * These two symbols are declared in a C file so that the linker
+ * uses R_ARM_RELATIVE relocation, rather than the R_ARM_ABS32 one
+ * it would use if the symbols were defined in the linker file.
+ * Using only R_ARM_RELATIVE relocation ensures that references to
+ * the symbols are correct after as well as before relocation.
+ *
+ * We need a 0-byte-size type for these symbols, and the compiler
+ * does not allow defining objects of C type 'void'. Using an empty
+ * struct is allowed by the compiler, but causes gcc versions 4.4 and
+ * below to complain about aliasing. Therefore we use the next best
+ * thing: zero-sized arrays, which are both 0-byte-size and exempt from
+ * aliasing warnings.
+ */
+
+char __bss_start[0] __attribute__((section(".__bss_start")));
+char __bss_end[0] __attribute__((section(".__bss_end")));
+char __image_copy_start[0] __attribute__((section(".__image_copy_start")));
+char __image_copy_end[0] __attribute__((section(".__image_copy_end")));
+char __rel_dyn_start[0] __attribute__((section(".__rel_dyn_start")));
+char __rel_dyn_end[0] __attribute__((section(".__rel_dyn_end")));