arm: relocate the exception vectors
This commit relocates the exception vectors.
As ARM1176 and ARMv7 have the security extensions, it uses VBAR. For
the other ARM processors, it copies the relocated exception vectors to
the correct address: 0x00000000 or 0xFFFF0000.
Signed-off-by: Georges Savoundararadj <savoundg@gmail.com>
Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
Cc: Tom Warren <twarren@nvidia.com>
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index fedd7c8..fdc05b9 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -81,12 +81,6 @@
mcr p15, 0, r0, c7, c10, 4 @ DSB
mcr p15, 0, r0, c7, c5, 4 @ ISB
#endif
-/*
- * Move vector table
- */
- /* Set vector address in CP15 VBAR register */
- ldr r0, =_start
- mcr p15, 0, r0, c12, c0, 0 @Set VBAR
bx lr
diff --git a/arch/arm/lib/relocate.S b/arch/arm/lib/relocate.S
index 8035251..b4a258c 100644
--- a/arch/arm/lib/relocate.S
+++ b/arch/arm/lib/relocate.S
@@ -6,6 +6,8 @@
* SPDX-License-Identifier: GPL-2.0+
*/
+#include <asm-offsets.h>
+#include <config.h>
#include <linux/linkage.h>
/*
@@ -52,6 +54,34 @@
cmp r2, r3
blo fixloop
+ /*
+ * Relocate the exception vectors
+ */
+#ifdef CONFIG_HAS_VBAR
+ /*
+ * If the ARM processor has the security extensions,
+ * use VBAR to relocate the exception vectors.
+ */
+ ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */
+ mcr p15, 0, r0, c12, c0, 0 /* Set VBAR */
+#else
+ /*
+ * Copy the relocated exception vectors to the
+ * correct address
+ * CP15 c1 V bit gives us the location of the vectors:
+ * 0x00000000 or 0xFFFF0000.
+ */
+ ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */
+ mrc p15, 0, r2, c1, c0, 0 /* V bit (bit[13]) in CP15 c1 */
+ ands r2, r2, #(1 << 13)
+ ldreq r1, =0x00000000 /* If V=0 */
+ ldrne r1, =0xFFFF0000 /* If V=1 */
+ ldmia r0!, {r2-r8,r10}
+ stmia r1!, {r2-r8,r10}
+ ldmia r0!, {r2-r8,r10}
+ stmia r1!, {r2-r8,r10}
+#endif
+
relocate_done:
#ifdef __XSCALE__