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authorTom Rini <trini@ti.com>2013-03-18 12:31:00 -0400
committerTom Rini <trini@ti.com>2013-03-18 14:37:18 -0400
commit0ce033d2582129243aca10d3072a221386bbba44 (patch)
tree6e50a3f4eed22007549dc740d0fa647a6c8cec5b /arch/arm/lib
parentb5bec88434adb52413f1bc33fa63d7642cb8fd35 (diff)
parentb27673ccbd3d5435319b5c09c3e7061f559f925d (diff)
Merge branch 'master' of git://git.denx.de/u-boot-arm
Albert's rework of the linker scripts conflicted with Simon's making everyone use __bss_end. We also had a minor conflict over README.scrapyard being added to in mainline and enhanced in u-boot-arm/master with proper formatting. Conflicts: arch/arm/cpu/ixp/u-boot.lds arch/arm/cpu/u-boot.lds arch/arm/lib/Makefile board/actux1/u-boot.lds board/actux2/u-boot.lds board/actux3/u-boot.lds board/dvlhost/u-boot.lds board/freescale/mx31ads/u-boot.lds doc/README.scrapyard include/configs/tegra-common.h Build tested for all of ARM and run-time tested on am335x_evm. Signed-off-by: Tom Rini <trini@ti.com>
Diffstat (limited to 'arch/arm/lib')
-rw-r--r--arch/arm/lib/Makefile1
-rw-r--r--arch/arm/lib/bss.c39
2 files changed, 40 insertions, 0 deletions
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 24c7e7a18a..6ae161a51d 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -42,6 +42,7 @@ ifndef CONFIG_SPL_BUILD
ifndef CONFIG_SYS_GENERIC_BOARD
COBJS-y += board.o
endif
+COBJS-y += bss.o
COBJS-y += bootm.o
COBJS-$(CONFIG_SYS_L2_PL310) += cache-pl310.o
diff --git a/arch/arm/lib/bss.c b/arch/arm/lib/bss.c
new file mode 100644
index 0000000000..99eda59137
--- /dev/null
+++ b/arch/arm/lib/bss.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__((used, section(".__bss_start")));
+char __bss_end[0] __attribute__((used, section(".__bss_end")));