Changeset c5b69a5e in mainline

Timestamp:

2012-09-04T08:25:30Z (12 years ago)

Author:

Jan Vesely <jano.vesely@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

ecd1a0a

Parents:

936b72e

Message:

arm32: Use the same method to enable high vectors for both armv6 and armv7.

Mandatory since armv6 (including).

File:

• kernel/arch/arm32/src/exception.c (modified) (3 diffs)

kernel/arch/arm32/src/exception.c

@@ -117 +117 @@
 
 #ifdef HIGH_EXCEPTION_VECTORS
-/** Activates use of high exception vectors addresses. */
+/** Activates use of high exception vectors addresses.
+ *
+ * "High vectors were introduced into some implementations of ARMv4 and are
+ * required in ARMv6 implementations. High vectors allow the exception vector
+ * locations to be moved from their normal address range 0x00000000-0x0000001C
+ * at the bottom of the 32-bit address space, to an alternative address range
+ * 0xFFFF0000-0xFFFF001C near the top of the address space. These alternative
+ * locations are known as the high vectors.
+ *
+ * Prior to ARMv6, it is IMPLEMENTATION DEFINED whether the high vectors are
+ * supported. When they are, a hardware configuration input selects whether
+ * the normal vectors or the high vectors are to be used from
+ * reset." ARM Architecture Reference Manual A2.6.11 (p. 64 in the PDF).
+ */
 static void high_vectors(void)
 {
         uint32_t control_reg = 0;
-        
-#if defined(PROCESSOR_armv7_a)
+        // TODO CHeck the armv6 way and implement it
+#if defined(PROCESSOR_armv7_a) | defined(ROCESSOR_armv6)
         asm volatile (
                 "mrc p15, 0, %[control_reg], c1, c0"
@@ -137 +150 @@
         control_reg |= CP15_R1_HIGH_VECTORS_BIT;
         
-#if defined(PROCESSOR_armv7_a)
+#if defined(PROCESSOR_armv7_a) | defined(ROCESSOR_armv6)
         asm volatile (
                 "mcr p15, 0, %[control_reg], c1, c0"
@@ -167 +180 @@
 void exception_init(void)
 {
+        // TODO check for availability of high vectors for <= armv5
 #ifdef HIGH_EXCEPTION_VECTORS
         high_vectors();