[PATCH] arm: mxs: Clear CPSR V bit to activate low vectors

[Marek Vasut <marex@denx.de>]

The MXS starts with CPSR V bit set, which makes the CPU jump to high vectors
in case of an exception. Those high vectors are located at 0xffff0000, which
is where the BootROM exception table is located as well. U-Boot should handle
exceptions on its own using its own exception handling code, which is located
at 0x0, i.e. at low vectors. Clear the CPSR V bit, so that the CPU would jump
to low vectors on exception instead, and therefore run the U-Boot exception
handling code.

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: "NXP i.MX U-Boot Team" <uboot-imx@nxp.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Lukasz Majewski <lukma@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
---
 arch/arm/cpu/arm926ejs/mxs/mxs.c      | 3 +++
 arch/arm/cpu/arm926ejs/mxs/spl_boot.c | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/arch/arm/cpu/arm926ejs/mxs/mxs.c b/arch/arm/cpu/arm926ejs/mxs/mxs.c
index 4d21e3df76e..d64a8328b04 100644
--- a/arch/arm/cpu/arm926ejs/mxs/mxs.c
+++ b/arch/arm/cpu/arm926ejs/mxs/mxs.c
@@ -85,6 +85,9 @@ void mx28_fixup_vt(uint32_t start_addr)
 		/* cppcheck-suppress nullPointer */
 		vt[i + 8] = start_addr + (4 * i);
 	}
+
+	/* Make sure ARM core points to low vectors */
+	set_cr(get_cr() & ~CR_V);
 }
 
 #ifdef	CONFIG_ARCH_MISC_INIT
diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_boot.c b/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
index 5598c552ab9..4a7dfc6a2ae 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
@@ -17,6 +17,7 @@
 #include <asm/arch/sys_proto.h>
 #include <asm/gpio.h>
 #include <asm/sections.h>
+#include <asm/system.h>
 #include <linux/compiler.h>
 
 #include "mxs_init.h"
@@ -104,6 +105,9 @@ static void mxs_spl_fixup_vectors(void)
 
 	/* cppcheck-suppress nullPointer */
 	memcpy(0x0, &_start, 0x60);
+
+	/* Make sure ARM core points to low vectors */
+	set_cr(get_cr() & ~CR_V);
 }
 
 static void mxs_spl_console_init(void)
-- 
2.40.1