[PATCH 3/3] arm: at91: add custom barebox-arm-head

[Jean-Christophe PLAGNIOL-VILLARD]

On at91 we need to put the size to load is the sram at the 6th exception vector

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
---
 arch/arm/Kconfig                                   |    1 +
 arch/arm/mach-at91/include/mach/barebox-arm-head.h |   33 ++++++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 arch/arm/mach-at91/include/mach/barebox-arm-head.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8b0a28d..ce32efb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -27,6 +27,7 @@ config ARCH_AT91
 	select GENERIC_GPIO
 	select CLKDEV_LOOKUP
 	select HAS_DEBUG_LL
+	select HAVE_MACH_ARM_HEAD
 
 config ARCH_EP93XX
 	bool "Cirrus Logic EP93xx"
diff --git a/arch/arm/mach-at91/include/mach/barebox-arm-head.h b/arch/arm/mach-at91/include/mach/barebox-arm-head.h
new file mode 100644
index 0000000..a9c8dd4
--- /dev/null
+++ b/arch/arm/mach-at91/include/mach/barebox-arm-head.h
@@ -0,0 +1,33 @@
+#ifndef __MACH_ARM_HEAD_H
+#define __MACH_ARM_HEAD_H
+
+#ifdef CONFIG_SHELL_NONE
+#define AT91_EXV6	".word _barebox_image_size\n"
+#else
+#define AT91_EXV6	".word _barebox_bare_init_size\n"
+#endif
+
+static inline void barebox_arm_head(void)
+{
+	__asm__ __volatile__ (
+#ifdef CONFIG_THUMB2_BAREBOX
+#error Thumb2 is not supported
+#else
+		"b reset\n"
+		"1: b 1b\n"
+		"1: b 1b\n"
+		"1: b 1b\n"
+		"1: b 1b\n"
+		AT91_EXV6				/* image size to load by the bootrom */
+		"1: b 1b\n"
+		"1: b 1b\n"
+#endif
+		".asciz \"barebox\"\n"
+		".word _text\n"				/* text base. If copied there,
+							 * barebox can skip relocation
+							 */
+		".word _barebox_image_size\n"		/* image size to copy */
+	);
+}
+
+#endif /* __ASM_ARM_HEAD_H */
-- 
1.7.10.4