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authorAlbert ARIBAUD <albert.u.boot@aribaud.net>2013-06-11 14:17:32 +0200
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2013-06-21 23:04:43 +0200
commitdf84502edffd1da48588a212b402602f032ed53d (patch)
treebcceb2b6665e8cad9a3ade14f86698e57446f14d /arch/arm/lib/sections.c
parent09d81184e103a07825d9f16e86e37c28d3605568 (diff)
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arm: generalize lib/bss.c into lib/sections.c
File arch/arm/lib/bss.c was initially defined for BSS only, but is now going to also contain definitions for other section-boundary-related symbols, so rename it for better accuracy. Also, remove useless 'used' attributes. Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net> Tested-by: Lubomir Popov <lpopov@mm-sol.com> Tested-by: Jeroen Hofstee <jeroen@myspectrum.nl> Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Diffstat (limited to 'arch/arm/lib/sections.c')
-rw-r--r--arch/arm/lib/sections.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/arm/lib/sections.c b/arch/arm/lib/sections.c
new file mode 100644
index 0000000..e52fec9
--- /dev/null
+++ b/arch/arm/lib/sections.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2013 Albert ARIBAUD <albert.u.boot@aribaud.net>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/**
+ * 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")));