4 files changed, 31 insertions, 5 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 32ba00bd0a2f..b674614d090b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -72,6 +72,14 @@ config FIQ
 config ARCH_MTD_XIP
         bool
 
+config VECTORS_BASE
+        hex
+        default 0xffff0000 if MMU
+        default DRAM_BASE if REMAP_VECTORS_TO_RAM
+        default 0x00000000
+        help
+          The base address of exception vectors.
+
 source "init/Kconfig"
 
 menu "System Type"
diff --git a/arch/arm/Kconfig-nommu b/arch/arm/Kconfig-nommu
index 8ce56e5bd78f..e1574be2ded6 100644
--- a/arch/arm/Kconfig-nommu
+++ b/arch/arm/Kconfig-nommu
@@ -25,3 +25,20 @@ config FLASH_SIZE
         hex 'FLASH Size' if SET_MEM_PARAM
         default 0x00400000
 
+config REMAP_VECTORS_TO_RAM
+        bool 'Install vectors to the begining of RAM' if DRAM_BASE
+        depends on DRAM_BASE
+        help
+          The kernel needs to change the hardware exception vectors.
+          In nommu mode, the hardware exception vectors are normally
+          placed at address 0x00000000. However, this region may be
+          occupied by read-only memory depending on H/W design.
+
+          If the region contains read-write memory, say 'n' here.
+
+          If your CPU provides a remap facility which allows the exception
+          vectors to be mapped to writable memory, say 'n' here.
+
+          Otherwise, say 'y' here.  In this case, the kernel will require
+          external support to redirect the hardware exception vectors to
+          the writable versions located at DRAM_BASE.
diff --git a/arch/arm/kernel/signal.h b/arch/arm/kernel/signal.h
index 9991049c522d..27beece15502 100644
--- a/arch/arm/kernel/signal.h
+++ b/arch/arm/kernel/signal.h
@@ -7,6 +7,6 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
-#define KERN_SIGRETURN_CODE     0xffff0500
+#define KERN_SIGRETURN_CODE     (CONFIG_VECTORS_BASE + 0x00000500)
 
 extern const unsigned long sigreturn_codes[7];
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 03924bcc6129..32b0570329e7 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -688,6 +688,7 @@ EXPORT_SYMBOL(abort);
 
 void __init trap_init(void)
 {
+        unsigned long vectors = CONFIG_VECTORS_BASE;
         extern char __stubs_start[], __stubs_end[];
         extern char __vectors_start[], __vectors_end[];
         extern char __kuser_helper_start[], __kuser_helper_end[];
@@ -698,9 +699,9 @@ void __init trap_init(void)
          * into the vector page, mapped at 0xffff0000, and ensure these
          * are visible to the instruction stream.
          */
-        memcpy((void *)0xffff0000, __vectors_start, __vectors_end - __vectors_start);
-        memcpy((void *)0xffff0200, __stubs_start, __stubs_end - __stubs_start);
-        memcpy((void *)0xffff1000 - kuser_sz, __kuser_helper_start, kuser_sz);
+        memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start);
+        memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start);
+        memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz);
 
         /*
          * Copy signal return handlers into the vector page, and
@@ -709,6 +710,6 @@ void __init trap_init(void)
         memcpy((void *)KERN_SIGRETURN_CODE, sigreturn_codes,
                sizeof(sigreturn_codes));
 
-        flush_icache_range(0xffff0000, 0xffff0000 + PAGE_SIZE);
+        flush_icache_range(vectors, vectors + PAGE_SIZE);
         modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
 }