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 fedd7c8f7e00d0427405173849e6c0743d6b886f..fdc05b942f15bb80415c295faba6832e689d8b01 100644 (file)
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -81,12 +81,6 @@ ENTRY(c_runtime_cpu_setup)
        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 803525156314e2b4b59a73d296965f773095041a..b4a258ce5c7917ca61bbaa5896036e57673f90d2 100644 (file)
--- 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 @@ fixnext:
        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__