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From: Sascha Hauer <s.hauer@pengutronix.de>
To: barebox@lists.infradead.org
Subject: [PATCH 2/3] ARM: Add assembler function to get runtime offset
Date: Mon, 10 Sep 2012 09:56:48 +0200	[thread overview]
Message-ID: <1347263809-2620-3-git-send-email-s.hauer@pengutronix.de> (raw)
In-Reply-To: <1347263809-2620-1-git-send-email-s.hauer@pengutronix.de>

This function returns the offset between the address barebox is linked at
and the address barebox is currently running at.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/arm/include/asm/barebox-arm.h |    1 +
 arch/arm/lib/Makefile              |    2 ++
 arch/arm/lib/runtime-offset.S      |   17 +++++++++++++++++
 3 files changed, 20 insertions(+)
 create mode 100644 arch/arm/lib/runtime-offset.S

diff --git a/arch/arm/include/asm/barebox-arm.h b/arch/arm/include/asm/barebox-arm.h
index b880dd4..3639365 100644
--- a/arch/arm/include/asm/barebox-arm.h
+++ b/arch/arm/include/asm/barebox-arm.h
@@ -42,5 +42,6 @@ extern char __ll_return[];
 void board_init_lowlevel(void);
 void board_init_lowlevel_return(void);
 void arch_init_lowlevel(void);
+uint32_t get_runtime_offset(void);
 
 #endif	/* _BAREBOX_ARM_H_ */
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 9d0ff7a..2e624cd 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -16,6 +16,8 @@ obj-y	+= lib1funcs.o
 obj-y	+= ashrdi3.o
 obj-y	+= ashldi3.o
 obj-y	+= lshrdi3.o
+obj-y	+= runtime-offset.o
+pbl-y	+= runtime-offset.o
 obj-$(CONFIG_ARM_OPTIMZED_STRING_FUNCTIONS)	+= memcpy.o
 obj-$(CONFIG_ARM_OPTIMZED_STRING_FUNCTIONS)	+= memset.o
 obj-$(CONFIG_ARM_UNWIND) += unwind.o
diff --git a/arch/arm/lib/runtime-offset.S b/arch/arm/lib/runtime-offset.S
new file mode 100644
index 0000000..ffa668c
--- /dev/null
+++ b/arch/arm/lib/runtime-offset.S
@@ -0,0 +1,17 @@
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+/*
+ * Get the offset between the link address and the address
+ * we are currently running at.
+ */
+ENTRY(get_runtime_offset)
+1:	adr r0, 1b
+	ldr r1, linkadr
+	subs r0, r1, r0
+THUMB(	subs r0, r0, #1)
+	mov pc, lr
+
+linkadr:
+.word get_runtime_offset
+ENDPROC(get_runtime_offset)
-- 
1.7.10.4


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  parent reply	other threads:[~2012-09-10  7:56 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-10  7:56 [PATCH v2] ARM lowlevel Sascha Hauer
2012-09-10  7:56 ` [PATCH 1/3] ARM lowlevel: Update function documentation Sascha Hauer
2012-09-10  7:56 ` Sascha Hauer [this message]
2012-09-10  7:56 ` [PATCH 3/3] ARM lowlevel: Use get_runtime_offset Sascha Hauer
  -- strict thread matches above, loose matches on Subject: below --
2012-09-09  9:47 [PATCH 1/3] ARM lowlevel: Update function documentation Sascha Hauer
2012-09-09  9:47 ` [PATCH 2/3] ARM: Add assembler function to get runtime offset Sascha Hauer
2012-09-09 11:12   ` Jean-Christophe PLAGNIOL-VILLARD
2012-09-09 16:27     ` Sascha Hauer

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